Electric wheel and wheeled machine equipped with such a wheel

Abstract

The present disclosure relates to an electric wheel comprising a hollow body and a motor housed at least partially inside the body, a motor carrier carrying the motor, and a transmission system transmitting the rotational motion of a rotor to the body, the transmission system having a driving element rotatably driven by the rotor of the motor carrier, and a driven element positioned on the body and comprising a set of teeth that rotates inseparably with the body, the body having a hub defining an axis of rotation of the wheel, the driving element and the driven element being engageable in meshing engagement, the set of teeth comprising axial teeth projecting from a plane perpendicular to the axis of rotation of the wheel, the motor carrier being equipped with at least one guide member, the body comprising at least one circular track coaxial with the axis of rotation of the wheel, the circular track having a contact surface perpendicular to the axis of rotation of the wheel, and the guide member or at least one guide member being capable of forming a rolling or sliding bearing contact with the contact surface.

Description

Technical Field

[0001] This disclosure relates to an electric wheel and a wheeled machine equipped with such a wheel. In particular, this disclosure relates to an electric wheel comprising a hollow body, an electric motor having a rotor and a stator, an electric motor carrier supporting the electric motor, and a transmission system. Background Technology

[0002] Motorized electric wheels with an internally integrated motor are known. This differs from the electric wheel disclosed in patent CN114954712, in which the motor appears to be located outside the wheel. For this type of wheel with the motor located outside, the problems encountered with the motor being located inside the wheel do not exist. Most electric wheels include a central motor coaxial with the wheel's axis of rotation. This results in wheels that are bulky and heavy due to the diameter and thickness of the motor. As shown in documents DE19738960 and US2011 / 115343, motorized wheels with an internally integrated motor have been developed.

[0003] Other electric wheel solutions. However, the solutions for transmitting the rotational motion of the rotor to the wheel body are complex and / or bulky and / or noisy and / or demanding in terms of positioning. Therefore, manufacturers of such wheels have been researching solutions to improve the compactness of the components by using motors that are as small as possible and therefore rotate at high speeds without the disadvantages caused by such limitations. Manufacturers are particularly seeking solutions characterized by simplicity and freedom of implementation, while also providing reliable and quiet solutions. Utility Model Content

[0004] One object of this disclosure is to provide an electric wheel whose design optimizes the transmission of rotational motion from the rotor to the body.

[0005] Accordingly, according to a first aspect of this disclosure, an electric wheel is provided, comprising a hollow body, a motor having a rotor and a stator, a motor carrier supporting the motor, and a transmission system that transmits the rotational motion of the rotor to the body. The transmission system has a drive element capable of being driven to rotate by the rotor mounted on the motor carrier supporting the motor, and a driven element positioned on the body. The body defines a cavity and has a hub defining the axis of rotation of the wheel. The transmission system transmits the rotational motion of the rotor to the body, and at least a portion of the motor carrier is accommodated within the body. The drive element and the driven element of the transmission system are capable of meshing, and the driven element includes a set of teeth that rotates inseparably from the body.

[0006] Furthermore, according to another aspect of this disclosure, an electric wheel is provided, comprising a hollow body, a motor having a rotor and a stator, a motor carrier supporting the motor, and a transmission system for transmitting the rotational motion of the rotor to the body. The transmission system has a drive element capable of being rotated by the rotor mounted on the motor carrier supporting the motor, and a driven element positioned on the body. The rotor is configured to rotate about an axis called a motor axis, which is coaxial with the rotational axis of the wheel. The body defines a cavity and has a hub defining the rotational axis of the wheel. The motor transmits the rotational motion of the rotor to the body. At least a portion of the transmission system and motor carrier are housed within the main body, and the drive element and driven element of the transmission system are capable of meshing engagement. The driven element includes a set of teeth that rotates inseparably from the main body. The set of teeth is characterized by teeth, referred to as axial teeth, projecting from a plane perpendicular to the rotation axis of the wheel. The motor carrier is equipped with at least one guide member, and the main body includes at least one circular track coaxial with the rotation axis of the wheel and having a contact surface perpendicular to the rotation axis of the wheel. The guide member, or at least one of the guide members, is capable of forming rolling or sliding bearing contact with the contact surface. By making the driven element into a set of teeth with axial teeth and combining it with one or more guide members located on the motor carrier equipped with the drive element, control over motion transmission can be maintained, and a quiet, reliable, and simplified meshing engagement can be achieved.

[0007] It is important to note that the torque transmitted by the motor applies a load to the gear train. This load acts in the direction that causes the driven and driven elements to separate. Even under these conditions, the guide member ensures meshing engagement.

[0008] According to one embodiment of this disclosure, at least a portion of the gear assembly and the main body are manufactured as a single piece. This design helps to simplify the transmission system.

[0009] According to one embodiment of this disclosure, the body includes two opposing walls forming a side wing or disc of a wheel, and a peripheral wall connecting the opposing walls to each other to form a rim of the wheel. A set of teeth protrudes from one of the opposing walls toward the other wall. The set of teeth is a circular set of teeth, the center of which is located on the axis of rotation of the wheel. At least one track is arranged on the opposing wall toward which the set of teeth extends. In summary, at least one of the opposing walls carries the set of teeth, while the other opposing wall carries a track or one of the tracks.

[0010] According to one embodiment of this disclosure, the gear assembly is surrounded by a track or at least one of the tracks. The position of the track or at least one of the tracks relative to the gear assembly provides effective guidance even when the wheel body deforms. In particular, in the case of two mutually facing tracks, the position of the tracks close to the rim allows for control over the distance between the two tracks, as this distance is primarily determined by the thickness of the rim. Alternatively, the gear assembly surrounds a track or at least one of the tracks. According to a particular aspect, when there is insufficient space between the gear assembly and the wheel rim, a single track is positioned facing the gear assembly, i.e., having approximately the same diameter as the gear assembly.

[0011] According to one embodiment of this disclosure, the driving element is a worm gear that meshes with the driven element. The worm gear directly meshes with the driven element.

[0012] According to one embodiment of the present disclosure, the worm has at least one helical thread having at least one turn, the thread or each thread being formed by two opposing tooth flanks connected by tooth crests, and the worm is a worm with a cylindrical profile, at least in the region where it meshes with the gear set.

[0013] The resulting transmission system offers numerous advantages. It features a circular gear set with axial teeth that directly mesh with a cylindrical worm gear. Specifically, the worm gear has an outer diameter or radius measured at the crest of each thread, which remains constant from one turn of the thread to the next. The axial teeth facilitate the manufacture of the gear set, particularly through injection molding, thus simplifying the overall manufacturing process. Similarly, the cylindrical profile of the worm allows for arbitrary axial positioning relative to the gear set, meaning no positional precision is required, further simplifying the transmission system. Furthermore, this worm gear can be manufactured by deforming and displacing the material using tools such as thread rolling dies. Finally, this transmission device is characterized by low noise compared to other types of transmission devices and high reliability, even when the wheel must move on uneven ground. Additionally, the cylindrical profile of the worm allows for positioning along its axis of rotation with a large degree of freedom, simplifying assembly without adversely affecting operation. Therefore, this design makes it easy to manufacture the transmission system while achieving a large reduction ratio, thus enabling the use of a compact motor.

[0014] According to one embodiment of this disclosure, the worm, referred to as a single-start worm, includes a single helical thread, and the thread of the worm has a helix angle and a thread pressure angle. The helix angle is greater than 10°, preferably greater than 15°, and the thread pressure angle corresponds to the angle formed by one of the tooth flanks of the thread and a plane orthogonal to the axis of rotation of the worm. The thread pressure angle is preferably greater than 25°. The pressure angle is non-zero.

[0015] The size of the helix angle promotes reversibility and makes the transmission system more efficient. Preferably, each tooth flank of the thread, or at least one of the threads, is in permanent contact with the gear assembly. Alternatively, one or the other tooth flank 112 may be in contact with the gear assembly, but not simultaneously, preferably selected according to the load direction corresponding to whether the worm is driven or driven and / or the rotation direction of the driving / driven element. Advantageously, backlash, also known as slop, is maintained to prevent any interference caused by dimensional changes in the elements when the gear assembly is in its assembled state within the gear. This arrangement allows motion to be transmitted in both rotational directions of the worm or gear assembly.

[0016] According to one embodiment of this disclosure, the motor carrier includes a housing, and the drive element is rotatably mounted within the housing. The drive element is coupled to the rotor of the motor, and a portion of the motor other than the rotor is positioned to support and contact a portion of the motor carrier that serves as an end stop, for fixing the portion of the motor other than the rotor in a non-rotatable manner.

[0017] According to one embodiment of this disclosure, the motor carrier includes at least two guide members capable of forming a support contact with the same track, the guide members extending on both sides of a plane radial to the track and passing through the engagement area between the driven element and the driving element.

[0018] According to one embodiment of this disclosure, there are at least two circular tracks positioned facing each other.

[0019] According to one embodiment of the present disclosure, the body includes two mutually facing walls forming a side wing or disc of a wheel and a peripheral wall connecting the mutually facing walls to each other to form a rim of the wheel, wherein at least two circular tracks are positioned facing each other on the mutually facing walls of the body.

[0020] According to one embodiment of this disclosure, the wheel includes an axle called a wheel hub, around which a wheel hub is mounted, the wheel hub supporting a motor carrier that is at least partially disposed within the body.

[0021] According to one embodiment of this disclosure, the motor carrier is mounted on the axle with a gap so that it can swing about an axis orthogonal to the axis of rotation of the wheel.

[0022] According to one embodiment of this disclosure, the motor axis and the rotation axis of the wheel are not parallel, and preferably do not intersect.

[0023] According to one embodiment of the present disclosure, the motor is arranged inside an imaginary cylindrical body, the axis of which coincides with the axis of rotation of the wheel, and the diameter of the imaginary cylindrical body is equal to the maximum diameter of the circular gear set.

[0024] Furthermore, according to another aspect of this disclosure, a wheeled lawnmower is provided, comprising at least one mowing component and at least one electrically driven wheel, characterized in that the wheel or at least one wheel is of the type described above. Attached Figure Description

[0025] This disclosure will be clearly understood by reading the following description of exemplary embodiments with reference to the accompanying drawings, in which:

[0026] Figure 1 A perspective view of an electric wheel according to the present disclosure is shown, wherein the constituent elements of the electric wheel are shown in an exploded view;

[0027] Figure 2 A perspective view of the electric wheel according to this disclosure in its assembled state is shown;

[0028] Figure 3 A schematic diagram of an electric wheel according to this disclosure is shown to illustrate the concept of a virtual or hypothetical cylindrical body;

[0029] Figure 4 A partial view of the cross-section of the electric wheel according to this disclosure is shown;

[0030] Figure 5 A partial view of the cross-section of the electric wheel according to this disclosure is shown;

[0031] Figure 6 A partial view of the longitudinal section of the electric wheel according to this disclosure is shown;

[0032] Figure 7 A partial view of the electric wheel according to the present disclosure in its electrically connected state to a power source is shown;

[0033] Figure 8 Two schematic partial cross-sectional views of an electric wheel according to this disclosure are shown, illustrating the oscillation of the motor-bearing component;

[0034] Figure 9 A perspective view of the motor carrier, motor, worm gear, and axle is shown, wherein the components are shown in an exploded view;

[0035] Figure 10 Various examples of guide components are shown schematically;

[0036] Figure 11 A partial cross-sectional view and two detailed views of the electric wheel according to this disclosure are shown;

[0037] Figure 12 A perspective view of a wheeled machine equipped with electric wheels according to this disclosure is shown;

[0038] Figure 13 The diagram shows how a part of the motor is secured by abutting against a motor carrier, with one view showing the assembled state and the other showing the unassembled state.

[0039] Figure 14 A partial perspective view of the interior of the electric wheel according to this disclosure is shown;

[0040] Figure 15 It shows Figure 14 Partial exploded view of some components;

[0041] Figure 16 A schematic partial view of the worm gear is shown, incorporating triangles to illustrate the helix angle. Detailed Implementation

[0042] As stated above, this disclosure relates to Figure 1 and Figure 2 Electric wheels of the type shown are 3. (e.g.) Figure 12 As shown, the electric wheel 3 can be coupled to the wheeled machine 1. In this example, the wheeled machine 1 is a lawnmower, which includes, for example, at least one mowing component 2 formed by rotating blades and at least one, preferably at least two, electrically driven wheels 3.

[0043] The lawnmower 1 can be an autonomous machine of the robotic type, i.e., an operatorless machine as shown in the figure, or a lawnmower with an operator walking behind it (such as a grass cutter), or a lawnmower with an onboard operator (such as a ride-on lawnmower). Obviously, other applications of the electric wheels, which will be described below, are conceivable without departing from the scope of this disclosure.

[0044] This wheeled machine can be equipped with an electric wheel 3, or at least one electric wheel is a drive wheel. The electric wheel 3 includes a hollow body 4 with a hub 5, which can be mounted on an axle 14 called a wheel axle. The hub 5 forms a circular recess. The hub 5 defines the axis of rotation XX' of the wheel 3. The hollow body 4 defines a cavity 6, within which is housed an electric motor 7 having a rotor 8 capable of rotating about the motor axis YY', and a transmission system 9 that transmits the rotational motion of the rotor 8 to the body 4 to cause the body 4 to rotate about the axis of rotation XX' of the wheel 3.

[0045] "The rotor of the electric motor 7" refers to the rotating elements of the electric motor, including the motor shaft (if such a shaft exists).

[0046] The motor 7 also includes a stator 24, which in this example covers all the static elements of the motor 7.

[0047] like Figure 4 As shown, the transmission system 9 that transmits the rotational motion of the rotor 8 to the main body 4 includes: a driven element 12 in the form of a gear set 10 that rotates indissociatively with the main body 4, and a drive element 11 that can be rotated by the motor 7.

[0048] The electric wheel 3 also includes a motor carrier 15 that carries the motor 7. The transmission system 9 that transmits the rotational motion of the rotor 8 to the main body 4 and at least part of the motor carrier 15 are housed within the main body 4. The drive element 11 and driven element 12 of the transmission system 9 are capable of meshing.

[0049] As described above, the driven element 12 includes a gear set 10 that rotates inseparably from the main body 4. Figure 6 As shown, the gear set 10 includes a tooth 120, referred to as an axial tooth, which protrudes from a plane P2 perpendicular to the rotation axis XX' of the wheel 3.

[0050] Gear set 10 is a circular gear set, and its center is located on the rotation axis XX' of wheel 3.

[0051] At least a portion of the tooth assembly 10 and the main body 4 are made of a single piece, for example, a synthetic material.

[0052] exist Figure 7 In the example shown, the main body 4 includes two facing walls 19 and a peripheral wall 20. The two facing walls 19 form the side wings or disc of the wheel 3, and the peripheral wall 20 connects the facing walls 19 to each other to form the rim of the wheel 3. The peripheral wall 20 may be fitted with a tread band, or the tread band may be attached to the peripheral wall 20.

[0053] exist Figure 11 In the example shown, a tread belt as indicated by reference numeral 200 is installed. With the peripheral wall 20 and the wall 19 forming the side wing of the wheel 3 connected, a portion of the tread belt 200, made of elastic material, is clamped between a portion of the peripheral wall 20 and a portion of one of the walls of the wall 19 forming the side wing of the wheel 3. This clamping provides a fluid seal for the cavity 6 defined by the body 4 at this location. In the example shown, the connection is performed using screws 27.

[0054] The opposing walls and peripheral walls can be made of composite materials, and the tooth assembly 10 is made as a single piece with one of the two opposing walls 19. Therefore, the teeth protrude from the surface of the wall toward the opposing wall. Here, the drive element 11 takes the form of a worm gear 110 that can be rotated by the motor 7.

[0055] Therefore, the worm 110 cannot rotate independently of the rotor 8 of the motor 7; that is, the worm is configured to be driven by the rotor's rotation. The worm 110 directly meshes with the gear set 10. The worm 110 and the motor axis YY' can be coaxial. Therefore, the worm can directly engage with the rotor 8 of the motor 7. This connection can be permanent or implemented in a way that allows for engagement / disengagement. In the example shown, the rotor is coupled to the motor shaft, and the worm is positioned in an extension of the motor shaft. Alternatively, the worm can be indirectly engaged, for example, via a gear that meshes with the rotor 8 of the motor 7.

[0056] The worm 110 extends in a plane P that is substantially perpendicular to the axis of rotation XX' of the wheel, meaning that in each case, the angular deviation of plane P relative to the direction perpendicular to the axis of rotation XX' does not exceed 10°. The worm 110 directly meshes with the gear set 10. Therefore, it can be understood that the rotation of the worm 110, which meshes with the rotor 8 of the motor 7, is driven by the meshing engagement of the worm 110 with the gear set 10, thereby rotating the body 4 of the wheel 3.

[0057] The worm 110 has at least one helical thread 111, which has at least one turn, that is, extends at least one full turn around its axis. For example... Figure 16 As shown, the thread, or each thread 111, is formed by two opposing tooth flanks 112, which are connected by tooth crests 113. Ideally, a worm, referred to as a single-start worm, comprises only one thread. The thread 111 is preferably a trapezoidal thread. When viewed in cross-section and as... Figure 16 As shown, the tooth flank 112 is preferably symmetrical about a plane intersecting the axis of rotation of the worm. Ideally, the worm thread 111 has a helix angle β greater than 10°, preferably greater than 15°, and a non-zero thread pressure angle α greater than 25°, which corresponds to the angle formed by one tooth flank of the thread and a plane orthogonal to the axis of rotation of the worm. The size of the helix angle promotes good worm / worm wheel reversibility and makes the transmission more efficient. Figure 16 As shown in the triangle, the tangent of the helix angle is equal to the pitch p of the thread divided by the product π×dp, where dp corresponds to the pitch circle diameter of the worm.

[0058] The worm 110 is a worm with a cylindrical profile, at least in the region where it meshes with the gear set 10; that is, at least one outer diameter de or radius of the worm 110, measured at the tooth crest of the gear set, remains constant. This provides greater freedom in positioning the worm along the longitudinal axis. In this region of meshing engagement, the pitch circle diameter dp and the module of the worm 110 remain constant.

[0059] Similarly, the inner diameter di of the worm (corresponding to the diameter of the cylindrical body of the worm's carrying helical thread) is constant. This helical thread of the worm forms helical ribs surrounding the cylindrical body of the worm. The cylindrical body of the worm defines a cylindrical journal that carries the thread. According to one embodiment, the tooth flanks 112 of the thread 111 are in permanent contact with the tooth set.

[0060] Alternatively, the tooth flank 112 of the thread 111 selectively contacts the tooth set according to the load direction corresponding to whether the worm is driven or driven and / or the rotation direction of the driving / driven element. Ideally, the axis of rotation of the worm 110 is separated from the plane parallel to the axis of rotation of the worm and passing through the axis of rotation XX' of the wheel 3 by a distance smaller than the maximum radius of the circular tooth set 10, expressed in millimeters, preferably less than or equal to half of the maximum diameter of the tooth set in millimeters minus 30 millimeters.

[0061] To ensure engagement even when the body 4 of wheel 3 deforms, the body 4 includes at least one circular track 17 arranged within the cavity 6 of the body 4 and rotating inseparable from the body 4. The center of the track is substantially located on the axis of rotation XX' of wheel 3, extending coaxially with the gear set 10. Typically, the track 17 surrounds the gear set 10. The track 17 is therefore as close as possible to the rim. The motor carrier 15 is equipped with one or more guide members 18 for each track. Each guide member 18 (such as a rolling bearing or pad) is capable of rolling or sliding contact with the track 17. The circular track 17, coaxial with the axis of rotation XX' of wheel 3, has a contact surface 170 perpendicular to the axis of rotation XX' of wheel 3, with the guide member 18 associated with the track 17 capable of rolling or sliding contact with this contact surface.

[0062] exist Figure 4 and Figure 5 In the example, two guide members 18 are provided, each formed by a rolling bearing. Each rolling bearing is connected to the motor carrier 15 by a threaded fastener. To provide optimal guidance without requiring additional guide members 18, the guide members 18 extend on both sides of a plane P1, which is radial to the track 17 and passes through the meshing engagement area between the worm gear 110 and the gear set 10.

[0063] Figure 10 Examples of guide members 18 are provided. Each guide member 18 can be a guide member that functions by scrolling or sliding, and can be rotating or non-rotating. Figure 10 As shown, each guide member 18 can be made as a single piece with another guide member.

[0064] The guide component can be installed as an attachment on the common load-bearing component.

[0065] Each circular track 17 is arranged to face the other circular track. The circular tracks 17 are thus arranged to face each other on the opposing walls 19 of the body 4, such that the guide member 18 is held and captured between the tracks.

[0066] To allow the wheel body 4 to be driven about the rotational axis XX' of the wheel 3, the wheel 3 includes an axle called axle 14, around which the hub 5 is mounted. Seals (such as...) Figure 11 (As shown in Figure 23) A fluid seal is provided between the axle 14 and the hub 5. Therefore, when the electric wheel 3 is in the assembled state, the cavity defined by the body is a sealed cavity. The axle 14 supports a motor carrier 15, which is at least partially arranged within the cavity of the body 4. The hub 5 is formed by a simple circular opening in at least one of the mutually facing walls 19 of the body 4 of the wheel 3, into which a portion of the axle 14 is inserted. The axle 14 supports the motor carrier 15, to which the motor 7 is directly or indirectly connected. The assembly formed by the axle 14 and the motor carrier 15 is a rotationally fixed assembly about which the body 4 of the wheel rotates. Figure 9 An example of the motor carrier 15 is given in the document.

[0067] like Figure 8 As shown, the motor carrier 15 includes a through housing, allowing it to slide onto the axle 14 to form an assembly with the axle, the two parts of which cannot move independently of each other. For this purpose, the housing may include slots for the axial ribs of the axle 14 to be inserted. The motor carrier 15 is preferably a component made of a composite material. Alternatively, the motor carrier 15 may be made of metal, particularly aluminum alloy. Here, the motor carrier 15 has an overall triangular shape, but its shape can vary. The motor carrier 15 will be at least partially housed within the cavity 6 of the body 4.

[0068] To allow the main body 4 to be mounted to have the ability to rotate about the wheel shaft 14, rolling bearing components are provided. These rolling bearing components are... Figure 8 As can be seen in the text.

[0069] The motor support component 15 includes a housing 16 (in Figure 1 As can be seen in the image, the axis of housing 16 is orthogonal to the axis of the receiving wheel shaft 14 that passes through the housing. Housing 16 is used to receive the drive element 11 (particularly the worm gear 110), which is mounted via at least one rolling bearing 22 and is capable of free rotation within housing 16. Figure 4 As shown, the rolling bearing or these rolling bearings 22, in addition to allowing the worm 110 to rotate relative to the motor carrier 15, also connect the worm 110 to the motor carrier 15 via the outer circumferential shoulder of the worm 110. For example... Figure 9 and Figure 13As shown, the associated rolling bearing 22 is axially secured in the housing 16 using locking members (such as U-clamps 26). Figure 13 As shown, the portion 71 of the motor 7, excluding the rotor 8, is positioned in support contact with the portion 151 of the motor carrier 15, which serves as a stop, to prevent this portion of the motor from being rotatably immobilized. Therefore, the non-rotating portion of the motor is non-rotatably immobilized through simple support contact with the motor carrier 15. The motor 7 is a cantilever extension of the worm gear 110.

[0070] To optimize the position of motor 7, such as Figure 3 As shown, the motor 7 is arranged inside an imaginary cylindrical body 13 (i.e., a virtual or fictitious cylindrical body), the axis of which coincides with the rotation axis XX' of the wheel 3, and its diameter is equal to the maximum diameter of the circular gear set 10. Ideally, the motor 7 is arranged inside the imaginary cylindrical body 13 (i.e., a virtual or fictitious cylindrical body), the axis of which coincides with the rotation axis XX' of the wheel 3, and its diameter is equal to the minimum diameter of the circular gear set 10.

[0071] like Figure 8 As shown, the motor carrier 15 is mounted on the axle 14 with a gap so that it can swing about an axis orthogonal to the rotation axis XX' of the wheel 3. This gap exists at a through-shell of the motor carrier 15, allowing it to slide on the axle 14. Therefore, even if the wheel 3 is deformed, the guide member 18 can still be supported on the body of the wheel 3 at the track 17. Thus, the guide member 18 provides guidance in parallel through support contact with the track 17, thereby ensuring the possibility of connection via the meshing engagement of the gear set 10 and the worm gear 110.

[0072] To maximize the compactness of the width (i.e., thickness) of the electric drive wheel 3 without adversely affecting its operation, the motor axis YY' and the rotation axis XX' of the wheel 3 are non-axial and non-parallel. Furthermore, the motor axis YY' and the rotation axis XX' of the wheel 3 do not intersect.

[0073] In fact, the motor axis YY' extends substantially perpendicular to the rotation axis XX' of the electric wheel 3 in plane P. That is, in each case, the deviation of plane P from the direction perpendicular to the rotation axis XX' of the electric wheel 3 does not exceed 10°. Figure 3 As shown, the motor axis YY' and the rotation axis XX' of the electric wheel 3 are orthogonal to each other, which allows for increased compactness in the width direction of the electric wheel 3.

[0074] Motor 7 is an electric motor of the smallest possible size. Ideally, for a robot, the motor has a total diameter of less than 40 mm; for a lawnmower, less than 50 mm; for a snowplow, less than 70 mm; and for a ride-on lawnmower, less than 120 mm. This motor 7 is a high-speed motor. Therefore, a speed reducer is absolutely necessary for the transmission system 9 that transmits the rotational motion of the rotor 8 of motor 7 to the body 4 of wheel 3. This speed reduction is achieved through the design of the transmission device that transmits the motion.

[0075] Wire 21 is used to supply power to motor 7. For example... Figure 7 and Figure 15 As shown, the wire 21 specifically passes through the axle and hub. When the battery supplying power to the motor is located outside the body 4, the wire 21 provides a connection to the power supply battery. When the battery 210 supplying power to the wheel motor is housed inside the cavity 6 of the body 4, the wire 21 allows for recharging of the power supply battery. It is evident that the same wheel can include one or more motors. Figure 14 and Figure 15 The control unit 25, visible in the diagram, controls the motor 7. This control unit 25 is in the form of an electronic computer system, including, for example, a microprocessor and working memory. Depending on a particular aspect, the control unit may be in the form of a programmable controller. In other words, the described functions and steps can be implemented in the form of a computer program or via hardware components (e.g., a programmable gate array). Specifically, the functions and steps performed by the control unit or its modules can be performed by an instruction set or computer module implemented in a processor or controller, or by components of the type of dedicated electronic components or programmable logic circuits (or FPGA, i.e., field-programmable gate array) or application-specific integrated circuits (ASIC). Computer components and electronic components can also be combined. When a designated unit or one or more means or modules of said unit are configured to perform a given operation, this means that the unit includes computer instructions and corresponding execution means that allow the operation to be performed, and / or the unit includes corresponding electronic components.

[0076] The control unit 25 and the battery 210 are fixed to the motor carrier 15 when they are located in the cavity 6 of the main body 4.

[0077] This type of wheel is simple to operate. Powering the motor 7 causes the rotor 8 to rotate, and the rotor itself drives the worm 110 to rotate. The worm engages with the gear set 10, which rotates inseparable from the body 4 of the wheel 3. Parallel guide members 18 provide guidance through load-bearing contact with the track 17, thereby ensuring the possibility of engagement via the meshing of the gear set and the worm.

Claims

1. An electric wheel (3) comprising a hollow body (4), a motor (7) having a rotor (8) and a stator (24), a motor carrier (15) carrying the motor (7), and a transmission system (9) for transmitting rotational motion of the rotor (8) to the body (4), the transmission system having a drive element (11) capable of being rotated by the rotor (8) mounted on the motor carrier (15) carrying the motor (7), and a driven element (12) positioned on the body (4), the rotor (8) being configured to rotate about an axis called a motor axis (YY'), the motor axis (YY') and the... The rotation axis (XX') of the electric wheel (3) is not coaxial, the body (4) defines a cavity (6) and has a hub (5) defining the rotation axis (XX') of the electric wheel (3), at least a portion of the motor (7), the transmission system (9) that transmits the rotational motion of the rotor (8) to the body (4) and the motor carrier (15) are housed within the body (4), and the drive element (11) and the driven element (12) of the transmission system (9) are capable of meshing, the driven element (12) comprising a set of teeth (10) that rotates inseparably from the body (4), characterized in that, The gear set (10) includes teeth (120) protruding from a plane (P2) perpendicular to the rotation axis (XX') of the electric wheel (3), the motor carrier (15) is equipped with at least one guide member (18), and the body (4) includes at least one circular track (17), the at least one circular track being coaxial with the rotation axis (XX') of the electric wheel (3) and having a contact surface (170) perpendicular to the rotation axis (XX') of the electric wheel (3), and the guide member (18) or at least one of the guide members being capable of forming a rolling or sliding bearing contact with the contact surface (170).

2. The electric wheel (3) according to claim 1, characterized in that, At least a portion of the tooth assembly (10) and the main body (4) are made as a single piece.

3. The electric wheel (3) according to any one of claims 1 and 2, characterized in that, The main body (4) includes two mutually facing walls (19) forming the side wings or disc of the electric wheel, and a peripheral wall (20) connecting the mutually facing walls (19) to each other and forming the rim of the electric wheel. The gear set (10) protrudes from one of the two mutually facing walls (19) toward the other of the two mutually facing walls (19). The gear set (10) is a circular gear set, the center of which is located on the rotation axis (XX') of the electric wheel (3). The track (17) or at least one of the tracks is arranged on the facing wall (19) toward which the gear set (10) extends.

4. The electric wheel (3) according to any one of claims 1 and 2, characterized in that, The gear set (10) is surrounded by the track (17) or at least one of the tracks.

5. The electric wheel (3) according to any one of claims 1 and 2, characterized in that, The driving element (11) is a worm (110) that meshes with the driven element (12).

6. The electric wheel (3) according to claim 5, characterized in that, The worm (110) has at least one helical thread (111) having at least one turn, the thread (111) or each thread being formed by two opposing tooth flanks (112) connected by tooth crests (113), and the worm (110) is a worm with a cylindrical profile, at least in the region where it meshes with the set of teeth.

7. The electric wheel (3) according to claim 6, characterized in that, The worm (110), referred to as a single-start worm, includes a single helical thread (111), and the thread (111) of the worm (110) has a helix angle (β) and a thread pressure angle (α), the helix angle being greater than 10°, and the thread pressure angle (α) corresponding to the angle formed by one of the tooth flanks (112) of the thread and a plane orthogonal to the axis of rotation of the worm (110), the thread pressure angle being greater than 25°.

8. The electric wheel (3) according to any one of claims 1 and 2, characterized in that, The motor carrier (15) includes a housing (16), and the drive element (11) is rotatably mounted in the housing. The drive element (11) is connected to the rotor (8) of the motor (7). A portion (71) of the motor (7) other than the rotor (8) is positioned to support and contact a portion (151) of the motor carrier (15) that serves as a stop, so as to fix the portion of the motor (7) other than the rotor (8) in a non-rotatable manner.

9. The electric wheel (3) according to any one of claims 1 and 2, characterized in that, The motor support (15) includes at least two guide members (18) capable of forming a support contact with the same track (17), the guide members (18) extending on both sides of a plane (P1) that is radial to the track (17) and passes through the engagement area between the driven element (12) and the drive element (11).

10. The electric wheel (3) according to any one of claims 1 and 2, characterized in that, There are at least two circular tracks (17) positioned facing each other.

11. The electric wheel (3) according to any one of claims 1 and 2, characterized in that, The main body (4) includes two facing walls (19) forming the side wings or disc of the electric wheel (3) and a peripheral wall (20) connecting the facing walls (19) to each other and forming the rim of the electric wheel, wherein at least two of the circular tracks (17) are positioned facing each other on the facing walls (19) of the main body (4).

12. The electric wheel (3) according to any one of claims 1 and 2, characterized in that, The electric wheel (3) includes an axle referred to as a wheel axle (14), around which the hub (5) is mounted, and the wheel axle (14) supports the motor carrier (15) which is arranged at least partially within the body (4).

13. The electric wheel (3) according to claim 12, characterized in that, The motor carrier (15) is mounted on the axle (14) with a gap so that it can swing about an axis orthogonal to the rotation axis of the electric wheel (3).

14. The electric wheel (3) according to any one of claims 1 and 2, characterized in that, The motor axis (YY') is not parallel to and does not intersect with the rotation axis (XX') of the electric wheel (3).

15. A wheeled machine (1) comprising at least one mowing component (2) and at least one electric wheel (3), characterized in that, The electric wheel (3) or at least one electric wheel is an electric wheel according to any one of claims 1 to 14.

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