In-wheel motor wheel and wheeled mowing vehicle provided with such a wheel

Abstract

The invention relates to an in-wheel motor wheel (3) comprising - a hollow body housing - an electric motor (7) - a support (15) for the motor, and - a motion transmission system (9) for transmitting motion between a driving element (11, endless screw) fixed to the rotor and a driven element (12) arranged on the body and comprising a toothing (10) with axial teeth. The body has a hub (5) defining an axis of rotation (XX') of the wheel. The rotor rotates about the motor axis (Y-Y'). The axis of the wheel is not coaxial with the motor axis. The driving element (11) and the driven element (12) are able to mesh with one another. The motor support (15) is provided with at least one guide member (18). The body comprises at least one circular track (17) that has a contact surface (170) perpendicular to the axis of the wheel with which the guide member is in rolling bearing contact.

Description

Description ELECTRIC WHEEL AND MOWING MACHINE EQUIPPED WITH SUCH A WHEEL

[0001] The present invention relates to an electric wheel and a rolling machine equipped with such a wheel.

[0002] It relates in particular to an electric wheel comprising a hollow body, a motor with a rotor and a stator, a support for said motor and a system for transmitting the rotational movement from the rotor to the body with a driving element capable of being driven in rotation by the rotor equipping the support for said motor and a driven element disposed on the body, said body delimiting a cavity and having a hub defining an axis of rotation of the wheel, the system for transmitting the rotational movement from the rotor to the body and at least a part of the motor support being housed inside said body and the driving and driven elements of the transmission system being capable of engaging by meshing, the driven element comprising teeth fixed in rotation to the body.

[0003] Motorized electric wheels that integrate a motor inside the wheel are known. This is not the case with patent CN 114954712, which describes an electric wheel where the motor appears to be positioned outside the wheel. For this type of wheel, where the motor is positioned externally, the problems encountered with a motor located inside the wheel are not present. Most electric wheels include a central motor coaxial with the wheel's axis of rotation. This results in a bulky and heavy wheel due to the motor's diameter and thickness. Other electric wheel solutions integrating a motor inside the wheel have been developed, as illustrated by documents DE19738960 and US 2011 / 115343. However, the chosen solutions for transmitting the rotor's rotational motion to the wheel body are complex and / or bulky and / or noisy and / or demanding in terms of positioning.Manufacturers of such wheels are therefore constantly searching for solutions to minimize the overall size by using the smallest possible motor, which can then rotate quickly without the drawbacks resulting from this constraint. Manufacturers are particularly looking for solutions characterized by... their simplicity, the freedom of execution they provide while offering a reliable and silent solution.

[0004] One aim of the invention is to provide an electric wheel whose design allows for optimization of the transmission of the rotational movement from the rotor to the body.

[0005] To this end, the invention relates to an electric wheel comprising a hollow body, a motor with a rotor and a stator, a support for said motor and a system for transmitting the rotational movement from the rotor to the body with a driving element adapted to be driven in rotation by the rotor equipping the support for said motor and a driven element disposed on the body, the rotor being configured to rotate about an axis called the motor axis, the motor axis and the axis of rotation of the wheel being non-coaxial, said body delimiting a cavity and having a hub defining an axis of rotation of the wheel, the motor, the system for transmitting the rotational movement from the rotor to the body and at least a part of the motor support being housed inside said body and the driving and driven elements of the transmission system being adapted to mesh, the driven element comprising teeth fixed in rotation to the body,characterized in that said gear teeth comprise axial teeth projecting from a plane perpendicular to the axis of rotation of the wheel, in that the drive support is equipped with at least one guide element, in that the body comprises at least one circular track coaxial with the axis of rotation of the wheel having a contact surface perpendicular to the axis of rotation of the wheel with which the one or at least one of the guide elements is capable of making contact by rolling or sliding support. The implementation of the driven element in the form of gear teeth with axial teeth, combined with the presence of one or more guide elements arranged on the drive support which is equipped with the driving element, makes it possible to control the transmission of motion and to have a quiet, reliable, and simplified meshing system.

[0006] It should be noted that the torque transmitted by the motor generates forces in the gear teeth. These forces pull the driven and driving elements apart. The guide components ensure proper meshing even under these conditions.

[0007] According to one embodiment of the invention, the teeth and at least part of the body are made from a single piece. This design contributes to simplifying the transmission system.

[0008] According to one embodiment of the invention, the body comprises two facing walls forming the sides or rims of the wheel and a circumferential peripheral wall connecting said facing walls and forming the rim of the wheel, in that the teeth project from one of the two facing walls towards the other of said facing walls, in that the teeth are circular teeth with a circle whose center is located on the axis of rotation of the wheel, and in that one or at least one of the guide tracks is located on the facing wall towards which the teeth extend. In summary, at least one of the facing walls carries the teeth and the other of the facing walls carries one or more of the guide tracks.

[0009] According to one embodiment of the invention, the teeth are surrounded by one or at least one of the tracks. The position of one or more of the tracks relative to the teeth ensures effective guidance, even in the event of deformation of the wheel body. In particular, when two tracks are positioned opposite each other, their proximity to the rim allows for precise control of the distance between them, as this distance is primarily determined by the rim thickness. Alternatively, the teeth surround one or at least one of the tracks. In a specific configuration, a single track is positioned opposite the teeth, i.e., approximately on the same diameter as the teeth, when there is insufficient space between the teeth and the wheel rim.

[0010] According to one embodiment of the invention, the driving element is a worm gear meshing with the driven element. The worm gear is directly meshed with the driven element.

[0011] According to one embodiment of the invention, the worm screw has at least one helical thread with at least one turn, the thread or threads are formed of two opposite flanks joined at one vertex and the worm screw is, at least in its area of ​​engagement with the teeth, a worm screw with a cylindrical profile. The construction of a transmission system with circular gears featuring axial teeth directly meshing with a cylindrical worm gear—that is, one with a constant outer diameter or radius measured at the crest of the thread(s) from one turn to the next—offers numerous advantages. The axial teeth facilitate the manufacturing of the gear teeth, particularly by injection molding, and thus simplify the production of the transmission system. Similarly, the cylindrical worm gear allows for arbitrary axial positioning relative to the teeth, eliminating the need for precise positioning and further simplifying the transmission system's construction. Furthermore, such a worm gear can be manufactured by material displacement using counterforming tools.Finally, this type of gear is characterized by its reduced noise compared to other types of gears and by its reliability, even when the wheel has to move over uneven ground. Furthermore, thanks to its cylindrical profile, the worm gear can be positioned along its axis of rotation with a significant degree of freedom, which facilitates assembly without affecting operation. This design therefore allows for easy manufacturing of the transmission system while achieving a high reduction ratio, enabling the use of a compact motor.

[0012] According to one embodiment of the invention, the single-threaded worm comprises a single helical thread and the worm thread has a helix angle greater than 10°, preferably greater than 15°, and a thread pressure angle corresponding to the angle formed by one of the thread flanks with a plane orthogonal to the axis of rotation of the worm, preferably greater than 25°. The pressure angle is non-zero.

[0013] The helix angle value allows for reversibility and improved efficiency of the transmission system. Preferably, the flanks of the thread(s) or at least one of the threads are each in permanent contact with the teeth. Alternatively, one or the other of the flanks 112 are in contact with the teeth, but not simultaneously; preferably alternately, according to the direction of the forces corresponding to the driving or driven state of the worm gear and / or the direction of rotation of the driving / driven element. Advantageously, what is called a backlash is maintained. The toothing, also known as backlash, prevents interference due to dimensional variations in the assembled components of the gear within the wheel. This arrangement allows for the transmission of motion in both directions of rotation of the worm gear or the teeth.

[0014] According to one embodiment of the invention, the motor support comprises a housing inside which the driving element is mounted freely for rotation, this driving element being coupled to the motor rotor, a part of the motor other than the rotor being positioned in contact against a part of the motor support forming a stop for immobilizing in rotation a part of the motor other than the rotor.

[0015] According to one embodiment of the invention, the motor support comprising at least two guide members capable of making contact with the same track, said guide members extend on either side of a radial plane to the track passing through the area of ​​engagement of the driven and driving elements.

[0016] According to one embodiment of the invention, there are at least two circular tracks arranged opposite each other.

[0017] According to one embodiment of the invention, the body comprising two facing walls forming the sides or sails of the wheel and a circumferential peripheral wall connecting said facing walls to each other and forming the rim of the wheel, the circular tracks, which are at least two in number, are arranged facing each other on the facing walls of the body.

[0018] According to one embodiment of the invention, the wheel comprises a shaft called the wheel shaft around which the hub is mounted, this shaft carrying the motor support disposed at least partially inside the body.

[0019] According to one embodiment of the invention, the motor support is mounted with play on said wheel shaft so as to be able to oscillate around an axis orthogonal to the axis of rotation of the wheel.

[0020] According to one embodiment of the invention, the drive shaft and the rotation shaft of the wheel are not parallel and preferably do not intersect.

[0021] According to one embodiment of the invention, the motor is arranged inside a fictitious cylinder whose axis coincides with the axis of rotation of the wheel and whose diameter is equal to the largest diameter of the circular teeth.

[0022] The invention also relates to a wheeled mowing machine comprising at least one mowing element and at least one electric drive wheel, characterized in that the wheel or at least one of the wheels is of the type mentioned above. Brief description of the drawings

[0023] The invention will be better understood upon reading the following description of exemplary embodiments, with reference to the attached drawings in which:

[0024] [Fig. 1] represents an exploded perspective view of the constituent elements of an electric wheel according to the invention;

[0025] [Fig. 2] represents a perspective view of an electric wheel according to the invention in the assembled state;

[0026] [Fig. 3] represents a schematic view of an electric wheel according to the invention to illustrate the concept of an imaginary or fictitious cylinder;

[0027] [Fig. 4] represents a partial cross-sectional view of an electric wheel according to the invention;

[0028] [Fig. 5] represents a partial cross-sectional view of an electric wheel according to the invention;

[0029] [Fig. 6] represents a partial longitudinal cross-sectional view of an electric wheel according to the invention;

[0030] [Fig. 7] represents a partial view of an electric wheel according to the invention in the state electrically connected to a power supply;

[0031] [Fig. 8] represents two schematic partial cross-sectional views of an electric wheel according to the invention to illustrate the oscillation of the motor support;

[0032] [Fig. 9] represents a perspective view of the motor support, the motor, the worm gear, and the wheel shaft, in exploded view of said elements;

[0033] [Fig. 10] represents, in schematic form, different examples of guiding elements;

[0034] [Fig. 11] represents a partial cross-sectional view of an electric wheel according to the invention associated with two detail views;

[0035] [Fig. 12] represents a perspective view of a rolling machine equipped with an electric wheel according to the invention;

[0036] [Fig. 13] represents, in the form of two views, one in the assembled state, the other in the unassembled state, the immobilization in rotation of a part of the motor by stop with the motor support;

[0037] [Fig. 14] represents a partial perspective view of the inside of an electric wheel according to the invention;

[0038] [Fig. 15] represents a partial exploded view of some of the elements in figure 14;

[0039] [Fig. 16] represents a partial schematic view of a worm gear associated with a triangle to illustrate the helix angle.

[0040] As mentioned above, the invention relates to an electric wheel 3 of the type shown in Figures 1 and 2. This electric wheel 3 is suitable for equipping a rolling machine 1, as illustrated in Figure 12. This rolling machine 1 is here a mowing machine which includes at least one mowing element 2 formed, for example, by a rotating blade and at least one, preferably at least two electric drive wheels 3.

[0041] This mowing machine 1 can be an autonomous machine of the robot type, i.e., without a driver as illustrated, or a mowing machine with a driver walking behind it, such as a lawnmower, or a mowing machine with an onboard driver, such as a riding mower. Obviously, other applications of the electric wheel, which will be described later, can be considered without departing from the scope of the invention.

[0042] One or more of the electric wheels 3 suitable for equipping such a rolling machine is a drive wheel. This electric wheel 3 comprises a hollow body 4 with a hub 5 suitable for mounting on a shaft 14, called the wheel shaft. This hub 5 forms a circular recess. This hub 5 defines an axis XX' of rotation for the wheel 3. The hollow body 4 delimits a cavity 6 inside which is housed an electric motor 7 with a rotor 8 capable of rotating around a motor axis YY' and a system 9 for transmitting the rotational movement of the rotor 8 to the body 4 to rotate the body 4 around the axis XX' of rotation of the wheel 3.

[0043] By "rotor of the electric motor 7", we mean here the rotating elements of said motor, these rotating elements including the motor shaft, when such a shaft is present.

[0044] Motor 7 also includes a stator 24 which here groups together all the static elements of motor 7.

[0045] As can be seen in figure 4, the system 9 for transmitting the rotational movement of the rotor 8 to the body 4 includes a driven element 12 in the form of a toothed gear 10 fixed in rotation to the body 4 and a driving element 11 suitable for being driven in rotation by the motor 7.

[0046] The electric wheel 3 also includes a support 15 for the motor 7. The system 9 for transmitting the rotational movement of the rotor 8 to the body 4 and at least part of the motor support 15 are housed inside said body 4. The driving elements 11 and driven elements 12 of the transmission system 9 are capable of engaging by meshing.

[0047] As mentioned above, the driven element 12 includes a toothing 10 fixed in rotation to the body 4. This toothing 10 includes axial teeth 120 which extend in projection from a plane P2 perpendicular to the axis of rotation XX' of the wheel 3 as shown in figure 6.

[0048] The tooth 10 is a circular tooth with a circle whose center is located on the axis of rotation XX' of the wheel 3.

[0049] The teeth 10 and at least part of the body 4 are made from a single piece, for example from synthetic material.

[0050] In the example shown in Figure 7, the body 4 comprises two facing walls 19 forming the sides or rims of the wheel 3 and a circumferential peripheral wall 20 connecting said facing walls 19 to each other and forming the rim of the wheel 3. The circumferential peripheral wall may incorporate a tread or this tread may be attached.

[0051] In the example shown in Figure 11, the tread, represented as 200, is attached. A portion of this tread 200, which is made of elastic material, is sandwiched between a portion of the circumferential peripheral wall 20 and a portion of one of the walls 19 forming a flank of the wheel 3 in the coupled state of the peripheral wall 20 and the wall 19 forming a flank of the wheel 3. This sandwiching ensures the sealing of the cavity 6 delimited by the body 4 at this point. The coupling is achieved, in the example shown, by means of screws 27.

[0052] The facing walls and the circumferential wall can be made of a synthetic material, and the teeth 10 are formed in one piece with one of the two facing walls 19. Thus, the teeth project from the face of said wall towards the facing wall. The driving element 11 is in the form of a worm gear 110 capable of being driven in rotation by the motor 7.

[0053] This worm gear 110 can therefore be rotationally coupled to the rotor 8 of the motor 7, meaning it is configured to be driven in rotation by the rotor. This worm gear 110 engages directly with the teeth 10. This worm gear 110 and the motor shaft YY' can be coaxial. Thus, the worm gear can directly engage with the rotor 8 of the motor 7. This connection can be permanent or made in a switchable / disconnectable manner. In the example shown, the rotor incorporates a motor shaft along the extension of which the worm gear is located. Alternatively, the worm gear can engage indirectly with the rotor 8 of the motor 7, for example, via a gear.

[0054] This worm gear 110 extends in a plane P substantially perpendicular to the axis of rotation XX' of the wheel, that is to say, perpendicular to within ±10° of said axis of rotation XX'. The worm gear 110 engages directly with the teeth 10. It is therefore understood that the rotation of the worm gear 110 engaged with the rotor 8 of the motor 7 drives, by meshing of the worm gear 110 with said teeth 10, the rotation of the body 4 of the wheel 3.

[0055] The worm screw 110 has at least one helical thread 111 with at least one turn, i.e., at least one revolution. Each thread 111 is formed of two opposing flanks 112 joined by a vertex 113, as illustrated in Figure 16. Ideally, the single-threaded worm screw comprises only one thread. This thread 111 is preferably trapezoidal. The flanks 112 are preferably shown in cross-section and, as illustrated in Figure 16, symmetrical with respect to a plane intersecting the axis of rotation of the worm screw. Ideally, the worm gear thread 111 has a helix angle p greater than 10°, preferably greater than 15°, and a thread pressure angle a corresponding to the angle formed by one of the thread flanks with a plane orthogonal to the worm gear's axis of rotation that is non-zero and preferably greater than 25°. The helix angle value ensures good worm gear reversibility and improved gear efficiency.The tangent of this helix angle is equal to the pitch p of the thread divided by the product fl x dp with dp corresponding to the pitch diameter of the worm gear, as illustrated by the triangle in Figure 16.

[0056] The worm 110 is, at least in its meshing zone with the teeth 10, a worm with a cylindrical profile, meaning that it has at least a constant diameter or outer radius measured at the tip of the thread. This provides a greater degree of freedom in terms of position along the longitudinal axis of the worm. The pitch diameter dp and the module of the worm 11 are constant in this meshing zone.

[0057] Similarly, the inner diameter di of the worm gear, corresponding to the diameter of the cylindrical body of the worm gear carrying the helical thread, is constant. This helical thread of the worm gear forms a helical rib around the cylindrical body of the worm gear. This cylindrical body of the worm gear defines a cylindrical bearing surface carrying said thread. In one embodiment, the flanks 112 of the thread 111 are each in permanent contact with the teeth.

[0058] Alternatively, the flanks 112 of the thread 111 are selectively in contact with the teeth according to the direction of the forces corresponding to the driving or driven state of the worm and / or the direction of rotation of the driving / driven element. Ideally, the axis of rotation of the worm 110 is offset by a plane parallel to the axis of rotation of the worm and passing through the axis XX' of rotation of the wheel 3 of a distance less than the largest radius of the circular toothing 10, this distance expressed in millimeters being preferably less than or equal to half the maximum diameter of the toothing expressed in millimeters minus 30.

[0059] To allow meshing, even when the wheel body 3 is deformed (4), the wheel body 4 includes, located inside the cavity 6 of the wheel body 4 and rotationally fixed to the wheel body 4, at least one circular track 17 with center located substantially on the axis XX' of rotation of the wheel 3, extending coaxially with the teeth 10. Generally, the track 17 surrounds the teeth 10. The track 17 is thus located as close as possible to the rim. The motor support 15 is equipped with one or more guide elements 18 for each track. Each guide element 18, such as a bearing or a pad, is suitable for making rolling or sliding contact with said track 17. This circular track 17, coaxial with the axis of rotation XX' of the wheel 3, has a contact surface 170, perpendicular to the axis of rotation XX' of the wheel 3, with which the guide elements 18 associated with said track 17 are suitable for making rolling or sliding contact.

[0060] In the example of Figures 4 and 5, two guide members 18 are provided, each formed by a bearing. Each bearing is screwed to the motor support 15. To ensure optimal guidance without having to multiply the guide members 18, the guide members 18 extend on either side of a radial plane P1 to the track 17 and passing through the meshing area of ​​the worm gear 110 and the teeth 10.

[0061] Examples of guide elements 18 are provided in Figure 10. Each guide element 18 can be a rolling or sliding guide element and may or may not be rotary. Each guide element 18 can be made in one piece with another guide element, as illustrated in Figure 10.

[0062] The guiding elements can be mounted in a separate manner on a common support.

[0063] Each circular track 17 is arranged opposite another circular track. The circular tracks 17 are thus arranged opposite each other on the walls 19 opposite the body 4 for the confinement of the guide elements 18 between said tracks.

[0064] To allow the wheel body 4 to rotate around the axis XX' of rotation of the wheel 3, the wheel 3 includes a shaft called the wheel shaft 14, around which the hub 5 is mounted. A seal, shown as 23 in Figure 11, provides a seal between the wheel shaft 14 and the hub 5. The cavity defined by the body is therefore, in the assembled state of the electric wheel 3, a closed cavity. The shaft 14 carries the motor support 15, which is at least partially located inside the cavity of the body 4. The hub 5 is formed by a simple circular opening inside at least one of the walls 19 facing the wheel body 4, into which a portion of the wheel shaft 14 is inserted. This wheel shaft 14 carries the motor support 15, to which the motor 7 is coupled directly or indirectly. The wheel shaft 14 / motor support 15 assembly forms a fixed rotating assembly around which the wheel body 4 rotates.An example of motor mount 15 is provided in figure 9.

[0065] As can be seen in Figure 8, the motor support 15 includes a through-hole so that it can be threaded onto the wheel shaft 14, forming a fixed assembly with it during movement. For this purpose, the hole may have grooves into which axial ribs of the wheel shaft 14 fit. This motor support 15 is preferably made of a synthetic material. Alternatively, this motor support 15 may be made of metal, in particular aluminum alloy. This motor support 15 is generally triangular in shape, but its shape may vary. This motor support 15 is housed at least partially inside the cavity 6 of the body 4.

[0066] To allow the body 4 to rotate around the wheel shaft 14, bearing elements are provided. These bearing elements are visible in Figure 8.

[0067] The motor support 15 includes a housing 16, visible in Figure 1, with an axis orthogonal to the axis of the through housing for receiving the wheel shaft 14. This housing 16 serves to receive the driving element 11, in particular the worm gear 110, which is mounted to rotate freely via at least one bearing 22 inside the housing 16. This bearing or these bearings 22 allow, in addition to the rotation of the worm gear 110 relative to the motor support 15, the coupling of the worm gear 110 to the motor support 15 by means of a peripheral shoulder. The external circumferential bearing of the worm gear 110 is visible in Figure 4. The associated bearing 22 is axially secured in the housing 16 by means of a locking device, such as a clip 26, visible in particular in Figures 9 and 13. A portion 71 of the motor 7, other than the rotor 8, is positioned in contact with a portion 151 of the motor support 15, which acts as a stop to prevent the rotation of said portion of the motor, as can be seen in Figure 13. Thus, the non-rotating portion of the motor is prevented from rotating by simple contact with the motor support 15. The motor 7 extends cantilevered from the worm gear 110.

[0068] To optimize the position of the motor 7, as illustrated in Figure 3, the motor 7 is arranged inside a fictitious cylinder 13, that is, an imaginary or virtual cylinder, whose axis coincides with the axis XX' of rotation of the wheel 3 and whose diameter is equal to the largest diameter of the circular teeth 10. Ideally, the motor 7 is arranged inside a fictitious cylinder 13, that is, an imaginary or virtual cylinder, whose axis coincides with the axis XX' of rotation of the wheel 3 and whose diameter is equal to the smallest diameter of the circular teeth 10.

[0069] As can be seen in Figure 8, the motor support 15 is mounted with clearance on the wheel shaft 14 to allow it to oscillate around an axis orthogonal to the axis XX' of rotation of the wheel 3. This clearance is present at the through-hole of the motor support 15, allowing the motor support 15 to be threaded onto the wheel shaft 14. Thus, even in the event of deformation of the wheel 3, the guide elements 18 can bear against the body of the wheel 3 at the level of the tracks 17. The guide elements 18 therefore simultaneously provide, through contact with the tracks 17, guidance that guarantees the possibility of coupling by meshing between the teeth 10 and the worm gear 110.

[0070] To minimize the width (i.e., thickness) of the electric drive wheel 3 without hindering its operation, the motor shaft YY' and the rotation axis XX' of wheel 3 are non-coaxial and non-parallel. Furthermore, the motor shaft YY' and the rotation axis XX' of wheel 3 do not intersect.

[0071] In practice, the motor axis YY' extends in a plane P that is substantially perpendicular, that is to say perpendicular to within ±10°, to the axis XX' rotation of the electric wheel 3. The motor axis YY' and the rotation axis XX' of the wheel 3 are orthogonal to each other as can be seen in figure 3, which allows to reduce the width of the electric wheel 3.

[0072] The motor 7 is an electric motor of the smallest possible dimensions. Ideally, the motor has an overall diameter of less than 40 mm for a robot, 50 mm for a lawnmower, 70 mm for a snowplow, and 120 mm for a tractor. Such a motor 7 rotates at high speed. It is therefore essential that the system 9 for transmitting the rotational motion from the rotor 8 of the motor 7 to the wheel body 4 incorporates a speed reducer. This speed reduction is achieved through the design of the gear that transmits the motion.

[0073] To supply power to the motor 7, an electrical wiring harness 21 is provided. This wiring harness 21, visible in Figures 7 and 15, passes through the wheel shaft and the hub. This harness 21 allows connection to the power supply battery when the motor's power supply battery is located outside the body 4. This wiring harness 21 allows recharging of the power supply battery when the wheel motor's power supply battery 210 is housed inside the cavity 6 of the body 4. Naturally, a single wheel can include one or more electric motors. The control of the motor(s) 7 is achieved using a control unit 25, visible in Figures 14 and 15. This control unit 25 is an electronic and computer system that includes, for example, a microprocessor and working memory.In one particular aspect, the control unit can take the form of a programmable logic controller (PLC). In other words, the functions and steps described can be implemented as a computer program or via hardware components (e.g., programmable gate arrays). In particular, the functions and steps performed by the control unit or its modules can be carried out by instruction sets or computer modules implemented in a processor or controller, or by dedicated electronic components, or by components such as field-programmable gate arrays (FPGAs), or application-specific integrated circuits. ASIC stands for Application-Specific Integrated Circuit. It is also possible to combine computer and electronic components. When it is specified that the unit, or means or modules of said unit, are configured to perform a given operation, this means that the unit includes computer instructions and the corresponding execution means to perform said operation, and / or that the unit includes corresponding electronic components.

[0074] The control unit 25 and the battery 210 are, when arranged inside the cavity 6 of the body 4, fixed to the motor support 15.

[0075] The operation of such a wheel is simple. The supply of electricity to the motor 7 causes a rotation of the rotor 8 which in turn drives the rotation of the worm gear 110 which meshes with the teeth 10 which are fixed in rotation to the body 4 of the wheel 3. The guide members 18 ensure in parallel, by contact with the tracks 17, a guidance guaranteeing a possibility of coupling by meshing between the worm gear and the teeth.

Claims

Demands

1. An electric wheel (3) comprising a hollow body (4), a motor (7) with a rotor (8) and a stator (24), a support (15) for said motor (7), and a system (9) for transmitting the rotational motion from the rotor (8) to the body (4), including a driving element (11) adapted to be driven in rotation by the rotor (8) and mounted on the support (15) of said motor (7), and a driven element (12) disposed on the body (4), the rotor (8) being configured to rotate about an axis called the motor axis (YY'), the motor axis (YY') and the axis of rotation (XX') of the wheel (3) being non-coaxial, said body (4) defining a cavity (6) and having a hub (5) defining an axis of rotation (XX') of the wheel (3), the motor (7), the system (9) for transmitting the rotational motion from the rotor (8) to the body (4), and at least a portion of the support (15) motor being housed inside said body (4) and the driving elements (11) and driven elements (12) of the transmission system (9) being capable of engaging by meshing,the driven element (12) comprising a toothed section (10) rotationally fixed to the body (4), characterized in that said toothed section (10) comprises axial teeth (120) which project from a plane (P2) perpendicular to the axis of rotation (XX') of the wheel (3), in that the motor support (15) is equipped with at least one guide member (18) and in that the body (4) comprises at least one circular track (17), coaxial with the axis of rotation (XX') of the wheel (3), having a contact surface (170), perpendicular to the axis of rotation (XX') of the wheel (3), with which the or at least one of the guide members (18) is able to come into contact by rolling or sliding support.

2. Electric wheel (3) according to claim 1, characterized in that the teeth (10) and at least part of the body (4) are made of a single piece.

3. Electric wheel (3) according to claim 1 or 2, characterized in that the body (4) comprises two facing walls (19) forming the sides or rims of the wheel and a circumferential peripheral wall (20) connecting said facing walls (19) to each other and forming the rim of the wheel, in that the teeth (10) project from one of the two facing walls (19) towards the other of said facing walls (19), in that the toothing (10) is a circular toothing of circle center disposed on the axis of rotation (XX') of the wheel (3) and that the or at least one of the tracks (17) is disposed on the opposite wall (19) in the direction of which the toothing (10) extends.

4. Electric wheel (3) according to any one of claims 1 to 3, characterized in that the toothing (10) is surrounded by the or at least one of the tracks (17).

5. Electric wheel (3) according to any one of claims 1 to 4, characterized in that the driving element (11) is a worm screw (110) meshed with the driven element (12).

6. Electric wheel (3) according to claim 5, characterized in that the worm (110) has at least one helical thread (111) with at least one turn, in that the thread or each thread (111) is formed of two opposite flanks (112) joined by a vertex (113) and in that the worm (110) is, at least in its area of ​​engagement with the teeth, a worm with a cylindrical profile.

7. Electric wheel (3) according to any one of claims 5 or 6, characterized in that the single-threaded worm (110) comprises a single helical thread (111) and in that the thread (111) of the worm (110) has a helix angle (0) greater than 10°, preferably greater than 15°, and a thread pressure angle (a) corresponding to the angle formed by one of the flanks (112) of the thread with a plane orthogonal to the axis of rotation of the worm (110) preferably greater than 25°.

8. Electric wheel (3) according to any one of claims 1 to 7, characterized in that the motor support (15) comprises a housing (16) inside which the driving element (11) is mounted freely for rotation, this driving element (11) being coupled to the rotor (8) of the motor (7), a part (71) of the motor (7) other than the rotor (8) being positioned in support contact against a part (151) of the motor support (15) forming a stop for immobilizing in rotation a part of the motor (7) other than the rotor (8).

9. Electric wheel (3) according to any one of claims 1 to 8, characterized in that the motor support (15) comprises at least two guide members (18) adapted to make contact with the same track (17), said guide members (18) extending on either side of a plane (P1) radial to the track (17) passing through the area of ​​engagement of the driven elements (12) and leading elements (11).

10. Electric wheel (3) according to any one of claims 1 to 9, characterized in that the circular tracks (17) are at least two in number and are arranged opposite each other.

11. Electric wheel (3) according to any one of claims 1 to 10, characterized in that the body (4) comprising two facing walls (19) forming the sides or sails of the wheel (3) and a circumferential peripheral wall (20) connecting said facing walls (19) to each other and forming the rim of the wheel, the circular tracks (17) which are at least two in number are arranged facing each other on the facing walls (19) of the body (4).

12. Electric wheel (3) according to any one of claims 1 to 11, characterized in that the wheel (3) comprises a shaft called wheel shaft (14) around which the hub (5) is mounted, this shaft (14) carrying the motor support (15) disposed at least partially inside the body (4).

13. Electric wheel (3) according to claim 12, characterized in that the motor support (15) is mounted with clearance on said wheel shaft (14) so ​​as to be able to oscillate around an axis orthogonal to the axis of rotation (XX') of the wheel (3).

14. Electric wheel (3) according to any one of claims 1 to 13, characterized in that the motor shaft (YY') and the rotation shaft (XX') of the wheel (3) are non-parallel and, preferably, do not intersect.

15. Rolling mowing machine (1) comprising at least one mowing element (2) and at least one electric drive wheel (3), characterized in that the wheel or at least one of the wheels (3) conforms to any one of claims 1 to 14.

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