Wheel generator with coupling system

Abstract

The present invention relates to a wheel generator (i.e., a converter for generating electrical energy in a rolling wheel of a vehicle from a deformation of a wheel tire generated by contact with a road surface), to a system for generating electrical energy comprising said converter, and to a vehicle or wheel comprising said system.

Description

[0001] The invention relates to a wheel generator, i.e. a converter for obtaining electrical energy in a rolling wheel of a vehicle from the deformation of the wheel tyre due to contact with a road surface. In particular, the invention relates to a converter having the features of the preamble of claim 1. The invention also relates to a system for obtaining electrical energy and a vehicle or a wheel comprising such a system. Prior art

[0002] Vehicle tires, especially pneumatic tires, deform under load in the contact surface area during rolling. In the process, the tire flexes and there is energy loss due to heat during power transmission. This effect is called deflection.

[0003] The force required to flex the tire is a major component of the rolling resistance and opposes the driving force of the vehicle. On the one hand, increased flexure therefore leads directly to increased fuel consumption of the vehicle and may also further shorten the service life of the tire. On the other hand, for the purpose of increasing the traction coefficient of the vehicle, and also for the purpose of enhancing driving comfort, a certain degree of deformation of the tire and thus an increase in the contact area of ​​the tire on the ground is very desirable. Typically, therefore, the air pressure in a pneumatic tire is set as a compromise between flexure and traction of the vehicle.

[0004] Energy losses due to tire deflection are one of the main components of the total energy losses in a vehicle, along with air resistance. Therefore, especially in the field of electric vehicles, the development of systems based on utilizing the deflection of the vehicle tires for regeneration (energy recovery, in particular for powering the vehicle battery) has been of interest for many years.

[0005] Various methods and systems are known in the prior art for obtaining energy on or in a vehicle tire, primarily for supplying electrical energy to a variety of tire monitoring sensors (eg, tire pressure sensors) arranged in the tire.

[0006] WO 2015 / 054763 A1 discloses a generator in a tire, in which a reciprocating motion is generated using a slight deformation and a reduction in space in an inner portion of the tire between the wheel and the tire when the wheel contacts the ground, and a device is activated to rotate the generator.

[0007] Furthermore, EP 3 540 921 A1 discloses an energy converter for generating electrical energy in a rolling wheel of a vehicle by utilizing elastic deformation of the wheel between a driving plane and a center axis of the wheel. The energy converter has a lever element with a protruding arm mounted rotatably about an axis of rotation, wherein the lever element is configured to be arranged in a wheel for a vehicle such that deformation of the tread towards the center axis of the wheel generates a force acting on a contact surface of the protruding arm, and the force acting on the contact surface causes a rotational movement of the protruding arm in a pumping rotational direction about the axis of rotation.

[0008] However, with the converters known in the prior art, direct contact occurs between the wheel tyre and a lever or protruding arm firmly connected to the rim. It has been shown that at higher speeds (which for typical car tyres may not exceed about 50 km / h), the direct contact between the lever and the wheel tyre leads to considerable heating of the tyre material at the contact point, causing its softening and increased viscosity, damaging the wheel and thus ultimately leading to failure of the generator.

[0009] US2004 / 0130157 A1 discloses a wheeled vehicle with a mechanical pump (and preferably a hydraulic pump) in its tire. As the tire rolls, the weight of the vehicle inflates the tank. The pressure in the tank is used to drive the vehicle directly or indirectly. The pump is driven by a bracket carrying rollers. These contact specially designed beads on the inside of the tire.

[0010] In all converters known in the prior art, the lever elements are further arranged at an angle of much less than 45° to the inside surface of the tire. On the one hand, this reduces the forces that occur due to the direct contact of the lever with the inside surface of the tire at the contact point. However, on the other hand, this reduces the effective displacement of the lever elements (i.e. the angular range they sweep during movement).

[0011] Finally, many converters proposed in the prior art are very demanding in terms of the space they require inside the tire, which makes changing a tire on the rim significantly more difficult. In some cases, the wheel, in particular the rim, must be disassembled and the converter removed before the tire can be changed. It is therefore desirable that the converter be designed as compact as possible, in particular to enable a tire change on the rim without removing the converter. At the same time, however, it is necessary to ensure that the large forces acting on the lever element and need to be transmitted to the generator are always transmitted reliably. Summary of the invention

[0012] The object of the present invention is to provide a converter for obtaining electrical energy in the rolling wheel of a vehicle from the deformation of the wheel tire caused by contact with the road surface, which converter does not have the problems of the prior art and in particular guarantees reliable operation with high efficiency even at relatively high speeds and is as compact as possible, thus allowing the tire to be changed on the rim without disassembling the converter.

[0013] According to the invention, this object is achieved by a converter for obtaining electrical energy in a rolling wheel of a vehicle from the deformation of the wheel tire due to contact with a road surface, the converter comprising: at least four lever elements, the at least four lever elements being rotatably accommodated at their first end and being configured at their second end to make contact with the inner side of the wheel tire via at least one contact element, so that the deformation of the wheel tire due to contact with the road surface causes a rotational movement of the lever elements; a mechanical coupling element system, the mechanical coupling element system being suitable for transmitting the force occurring due to the rotational movement of the lever elements; and at least one generator, the at least one generator being configured to convert the force preferably transmitted by the mechanical coupling element system into electrical energy, wherein the lever elements are each pivotally mounted at their first end by means of an axis, and the axis is configured to transmit the force of the rotational movement, the mechanical coupling element system having at least two coupling elements for each axis of each lever element, the at least two coupling elements each being arranged to transmit the force of the rotational movement to the axis of an adjacent lever element or to an intermediate axis, and there being at least one planetary gear, the at least one planetary gear being arranged to transmit the rotational movement of the axis or the intermediate axis to the generator.

[0014] The invention is based on the recognition that, in the case of known generators, the levers or protruding arms of the generator, which are firmly connected to the rim, cause friction when they come into direct contact with the inside of the wheel tire and thus generate a large amount of local heat. During its flexural movement, the wheel tire moves non-linearly relative to the rim, i.e., starting from the rim as a reference system, the movement of the defined part of the wheel tire that comes into contact with the road surface during the rotation of the wheel is not in a straight line, but around a surface. In the case of a lever or protruding arm that is only rotatably mounted, when the wheel rotates, the wheel tire and the corresponding contact surface of the contact lever or protruding arm thus move relative to each other, resulting in friction therebetween. The latter seems to lead to malfunctions of the known generator, in particular at higher speeds (down to above about 50 km / h for typical car tires). In addition, the lever element is arranged at an angle of much less than 45° to the inside surface of the tire. On the one hand, this reduces the forces and therefore the friction that occur due to the direct contact of the lever with the wheel tire at the contact point. However, on the other hand, this reduces the effective displacement of the lever element (i.e., the angular range they sweep during the movement).

[0015] Secondly, the systems known in the prior art are very demanding in terms of the space they require inside the tire, which makes it significantly more difficult to change a tire on the rim. In some cases, the wheel, in particular the rim, must be disassembled and the converter removed before the tire can be changed.

[0016] According to the invention, it has now surprisingly been found that these problems can be solved by means of a combination of measures, namely by means of the fact that, on the one hand, at least one contact element, typically a roller or a part of a roller (roller segment), is rotatably accommodated at the second end of the lever element, such that the contact element establishes contact between the lever element and the wheel tyre, and the axis of rotation of the contact element extends substantially parallel to the axis of rotation of the wheel. The contact element is rotatably accommodated at the second end of the lever element about the axis of rotation and establishes contact between the lever element and the wheel tyre. Due to its rotatable mounting, it is able to compensate for relative movements between the wheel tyre and the lever element via its own rolling movement and thus minimize or prevent friction between the wheel tyre and the lever element.

[0017] On the other hand, it has been found that by means of a specific arrangement of a mechanical coupling element system with at least two coupling elements for each shaft of each lever element, said coupling elements being arranged to transmit the force (energy) of the rotational movement to the shaft of an adjacent lever element or to an intermediate shaft, an extremely compact design is possible, which also allows a reliable transmission of larger forces. If at least one planetary gear is additionally present, which is arranged to transmit the rotational movement of the shaft to the generator, it is possible to achieve a power transmission from the mechanical coupling element system to the generator with minimal space requirements, while achieving an appropriate gear ratio.

[0018] The present invention will now be described in further detail based on preferred embodiments.

[0019] The converter for obtaining electrical energy in a rolling wheel of a vehicle from the deformation of the wheel tire due to contact with a road surface according to the invention comprises: at least four lever elements, which are rotatably accommodated at their first end and are configured at their second end to make contact with the inner side of the wheel tire via at least one contact element, so that the deformation of the wheel tire due to contact with the road surface causes a rotational movement of the lever elements. The wheel typically comprises a rim and a wheel tire that can be filled with compressed air.

[0020] A rotational movement of the lever element is typically understood as a partial rotation (pivoting movement) of the lever element at the first end about the axis of rotation N. The lever element is therefore particularly designed to detect deformations of the wheel tire occurring in the area of ​​the contact surface during the rolling of the loaded wheel on a substantially flat driving surface by means of the contact element and to convert them into a rotational movement about the axis of rotation N at the first end of the lever element. The lever element itself therefore has no direct contact with the inside of the tire, but is in contact therewith only via at least one contact element. According to one embodiment of the converter, it or the lever element is therefore configured such that the contact surface of the contact element of the lever element is designed to establish contact with the inner surface of the wheel tire.

[0021] Each lever element is rotatably mounted at its first end, preferably on a support structure or a rim of the wheel. In principle, the direction of rotation N at the first end of the lever element may have any direction extending substantially parallel to its corresponding contact surface on the inside of the wheel tire, since a flexural movement of the inside of the wheel tire (i.e. a movement towards the rim) may thereby result in a partial rotation of the lever element. In a preferred embodiment, the fulcrum of the lever element extends substantially parallel to the rotation axis of the wheel.

[0022] In the context of the present invention, substantially parallel preferably means a deviation from parallel of less than 10°, more preferably less than 5°.

[0023] In a preferred embodiment, the lever element is designed in one piece. In this embodiment, it preferably supports one (in particular only one) contact element, which is rotatably mounted thereon. In an alternative embodiment, which is also preferred, the lever element is formed in at least two parts (i.e., consists of at least two (preferably only two) parts), which are mechanically connected and preferably partially rotatable relative to each other. For example, a first part of the lever element forms a first end, at which the lever element is rotatably mounted, and a second part constitutes a second end supporting the one or more contact elements. The partial rotatability of the first part relative to the second part enables a rotational movement (rocking movement) of the lever element to be compensated during the contact of the contact element with the inner side of the deflecting tire and at the same time maintains the contact of the contact element with the inner side of the tire. In this alternative embodiment, the lever element (preferably each lever element) preferably supports at least two (in particular only two) contact elements, which are rotatably mounted on the lever element, in particular on the second part. Particularly preferably, in the alternative embodiment, the lever element thus consists of a first part having a first end and a second part, which constitutes a holding element for at least two, preferably two contact elements, and thus preferably constitutes a rolling slide. The latter is configured so that both contact elements can be in contact with the inside of the wheel tire (the surface of the inside of the tire) at the same time. In this way, the contact surface on the inside of the wheel tire can be increased and the point forces and thus the point loads of the wheel tire can be reduced. The second part (hereinafter also referred to as "slider") is mounted partially rotatable on the lever element in such a way that when the lever element is "pulled out" from the rest position, for example, all contact elements carried by the slider are in contact with the wheel tire. In a preferred embodiment, when the contact elements are in contact with the inside of the wheel tire, the distance between the axes of rotation of the contact elements carried by (each) slider is approximately equal to (±10%, preferably ±5%) the distance between the axes of rotation of two adjacent contact elements of the second (directly) adjacent lever element. For example, the distance between the axes of rotation of the second contact elements carried by each slider of preferably 8 or 12 lever elements is preferably approximately equal to (±10%, preferably ±5%) the distance between the axes of rotation of the contact element of the first slider and the axis of rotation of the nearest contact element of the (directly) adjacent slider. In other words, the angle β that the two rotation axes of the contact element of the slider cover relative to the rotation axis of the wheel is preferably approximately 360° / 2*n, wherein n is the number of lever elements or sliders. Thus, the angle β that the two rotation axes of the contact element of the slider cover relative to the rotation axis of the wheel is preferably approximately half (±10%, preferably ±5%) of the angle α between the two lever elements.The angle α is the angle spanned by the axis of rotation of two adjacent lever elements (in other words, the lever elements are identically located and are also the axis of rotation of the slide, as shown in FIG6 ) relative to the axis of rotation of the wheel. The angle α therefore corresponds to 360° / n, where n is the number of lever elements. In this embodiment, the force distribution is uniform over the wheel tire (the surface on the inside of the tire) when the contact elements contact the wheel tire at approximately the same distance. In the case of 12 lever elements and two rollers per slide, 24 approximately equally (±10%, preferably ±5%) spaced contact elements are in contact with the inside of the tire (the angle β between the corresponding adjacent contact elements (both the two contact elements of one slide and the corresponding adjacent contact elements of two adjacent slides) is then approximately 15° (±10%, preferably ±5%)). The approximately equally spaced contact elements on the inside of the tire also result in a more uniform transfer of energy to the lever elements, since this means that in a typical flexural deformation (e.g. of a car or truck tire), at least two lever elements are always displaced simultaneously via their slides.

[0024] In one embodiment, the (preferably two) contact elements of the slider (preferably when they are designed as rollers) are surrounded or wrapped by a belt or strip. For example, the belt or strip extends directly around the two rollers or also around a deflection roller, which can also be arranged on the slider. In this case, the surrounded contact elements (preferably rollers) are in contact with the inside of the tire via the belt or strip. This increases the effective contact surface of the contact elements with the inside of the tire and thus reduces the point loads and thus the loads on the tire. For example, the belt can be designed as a V-belt or a multi-V belt to prevent it from detaching from the rollers.

[0025] In a preferred embodiment, the converter has at least six (in particular at least 6 to 16, most preferably 8 to 12) lever elements.

[0026] In a preferred embodiment, the converter has, in particular at least 6 to 16, most preferably 8 to 12, lever elements which are arranged rotationally symmetrically about the axis of rotation of the wheel.

[0027] The lever element of the converter according to the invention comprises at least one contact element. The lever element comes into contact with the inner side of the tire via the contact element, so that the deformation of the wheel tire caused by the contact with the road surface causes a (partial) rotational movement of the lever element. This means that (each) lever element has at least one contact element, which is rotatably mounted in or on the lever element at the second end, so that the contact element establishes contact between the lever element and the wheel tire.

[0028] The (each) lever element preferably does not come into direct contact with the inside of the wheel tyre in any position of its rotation about its rotation axis N at its first end (under normal operation), i.e. it does not contact the inside of the wheel tyre. In contrast, if the lever element has been rotated accordingly at the first end about the rotation axis towards the tyre surface (away from the rim), only the one or more contact elements come into contact with the inside of the wheel tyre, i.e. it contacts the inside of the wheel tyre. The rotation axis of the one or more contact elements is substantially parallel to the rotation axis of the wheel. If more than one contact element is present on the lever element, their rotation axes are parallel. The possibility of the contact element being rotatably mounted on the lever element on the one hand and rotatable about an axis substantially parallel to the rotation axis of the wheel on the other hand enables relative movements between the wheel tyre and the lever element to be compensated and thus minimizes friction between the wheel tyre and the lever element. The contact element is preferably substantially rotationally symmetrical with respect to its rotation axis in terms of its dimensions, at least in the region in which it comes into contact with the inside of the wheel tyre. In particular, it is therefore a roller or a partial roller (roller segment). The roller has a substantially cylindrical shape (the axis of rotation of the contact element then corresponds to the cylinder axis), possibly with a cylindrical outer surface that is curved outwards in a circular manner (barrel-shaped roller). A typical suitable radius of the contact element (i.e. a preferred roller radius) is a radius for which the ratio of the radius of the contact element to the radius of the inside of the wheel tyre R (around the wheel centre) is in the range of 0.04 to 0.08, preferably 0.05 to 0.07. Thus, in particular for car tyres, a typical suitable roller radius is in the range of 18 mm to 30 mm. The contact element is preferably freely rotatable relative to its fulcrum, in particular freely rotatable through 360°. This means that the contact element is preferably freely rotatable around the axis of rotation, in particular completely around its own axis, around which the contact element is rotatably mounted and fixed on / in the lever element or the slide. This ensures uniform contact of the contact element with the inside of the wheel tyre even when running at relatively high speeds.

[0029] According to a preferred embodiment, the ratio (A / R) of the distance A of the fulcrum N of the lever element from the wheel center M to the inner radius R of the wheel tire is in the range of 0.55 to 0.60, preferably 0.56 to 0.59.

[0030] According to a preferred embodiment, the ratio (B / R) of the distance B from the fulcrum N of the lever element to the contact point K between the contact element and the inner side of the wheel tire (when each lever element has multiple contact elements, the one with the largest distance from the fulcrum N) to the inner radius R of the wheel tire is in the range of 0.44 to 0.55, preferably 0.45 to 0.53, and in particular 0.46 to 0.50.

[0031] In the converter according to the invention, the lever element rotatably accommodated at its first end can come into contact with the inside of the wheel tire via at least one contact element. This means that the sum (A+B) of the distance A from the fulcrum N of the lever element to the wheel center M and the distance B from the fulcrum N to the contact point K of the contact element with the inside of the wheel tire (in the case of multiple contact elements per lever element, the contact point is the contact point with the greatest distance from the fulcrum N) is greater than the radius R of the inside of the wheel tire ((A+B) / R)>1).

[0032] The displacement of the lever elements, i.e. the angular range they sweep during their movement, is preferably significantly increased if the ratio (A+B) of the sum of the distance A of the fulcrum N of the lever element from the wheel center M and the distance B of the fulcrum N from the contact point K of the contact element with the inside of the wheel tire (in the case of a plurality of contact elements per lever element, the contact point being the contact point with the greatest distance from the fulcrum N) to the radius R of the inside of the wheel tire is in the range of 102% to 110%, in particular 103% to 107%. This value range of (A+B) / R means that the arrangement of the lever elements is significantly more "stretched" than in the prior art, so that they are arranged almost vertically relative to the inside of the tire. Although this increases the forces and relative movements between the wheel tire and the lever elements, it achieves a high efficiency, since only by increasing the angular range swept by the lever elements during their movement can an efficient drive of the generator be ensured.

[0033] The radius R here always refers to the radius of the unloaded tire from the wheel center to the inside of the wheel tire (inside tire surface). The fulcrum N of the lever element refers to the fulcrum of the lever element at its first end.

[0034] The converter according to the present invention further comprises a mechanical coupling element system. The mechanical coupling element system is configured and adapted to transmit the force (energy) occurring due to the rotational movement of the lever element, i.e. preferably to the one or more generators. In this case, the mechanical coupling element system comprises at least two coupling elements for each axis of each lever element. Typical suitable coupling elements are gears and axles, belts, chains, etc. The coupling element preferably comprises at least one chain or belt, in particular a toothed belt and / or a multi-V belt. In this case, the mechanical coupling element system typically also comprises corresponding means for engaging the coupling element with the axis of the lever element, for example, gears, grooved gears, etc.

[0035] The forces (energy) of all lever elements of the converter are preferably transmitted to a (common) mechanical coupling element system, for example a set of chains or belts, in particular toothed belts and / or poly-V belts. The mechanical coupling element system preferably comprises at least two coupling elements for each axis of each lever element, wherein all axes of the lever elements are frictionally connected with the corresponding adjacent axes of the lever elements in each case via coupling elements or via intermediate shafts by means of the mechanical coupling element system. Since the lever elements are preferably arranged rotationally symmetrically around the axis of rotation of the wheel (i.e. in a ring shape), a "ring closure" is preferably established, which means that all axes of the lever elements are frictionally connected with the corresponding adjacent axes of the lever elements around the wheel via coupling elements by means of the mechanical coupling element system. Therefore, the number of coupling elements of the mechanical coupling element system preferably corresponds to the number of axes of the lever elements. In other words, preferably there are no intermediate shafts.

[0036] Thus, the mechanical coupling element system enables frictional connection between all lever elements of the converter. This allows the one or more generators to be driven more continuously. The mechanical coupling element system is preferably also frictionally connected to a plurality of generators (most preferably all generators) of the converter. By distributing the total energy generated by the lever elements to several generators, they can be operated continuously, which allows efficient recovery of energy with minimal material input.

[0037] In a preferred embodiment, the converter therefore comprises a system of mechanical coupling elements, which is designed as a belt, in particular a V-belt, a toothed belt or a multi-V belt, and which establishes a friction connection of all lever elements of the converter (preferably 8 or in particular 12) with all generators (preferably three or four). In this case, it is preferred that the belts are respectively guided around rollers or gears connected to the shafts of the lever elements and around rollers or gears connected to the shafts of adjacent lever elements. In one embodiment, there may be one or more inserted free-rotating rollers or rollers on intermediate shafts connected via coupling elements. Preferably, there are no inserted free-rotating rollers or rollers that are not connected to the shafts of the lever elements and / or are only connected to the generators. Therefore, in a most preferred embodiment, the converter comprises a system of mechanical coupling elements, which comprises 12 belts, in particular V-belts, toothed belts or multi-V belts, and provides a friction connection of all shafts of the 12 lever elements.

[0038] Finally, the converter according to the invention comprises at least one generator configured to convert the force (energy) obtained by the rotational movement of the one or more lever elements, preferably transmitted by the system of mechanical coupling elements, into electrical energy. In a preferred embodiment, the converter has at least two (in particular at least 2 to 12, most preferably 3 to 8, for example three or four) generators arranged rotationally symmetrically around the axis of rotation of the wheel. The number of lever elements is preferably a multiple of the number of generators.

[0039] According to the invention, at least one planetary gear is provided, which is arranged to transmit the rotational movement of the shaft of the lever element to the generator. Planetary gears (also referred to as epicyclic gears in the prior art) are gear or friction gear systems that, in addition to a fixed shaft, have an axis that revolves in a circular orbit around a fixed frame. Therefore, a distinction is made between a central gear or sun gear mounted on a fixed shaft and an orbit, planetary gear or star gear mounted on a rotation axis. The star gear rotating on the rotation axis orbits around the central gear, similar to the way the planet orbits around the sun. The bracket that holds the rotation axis itself rotates around the fixed axis. Suitable materials (e.g., stainless steel) for suitable planetary gears, in particular for the planetary gears used according to the invention, are known in the prior art. Planetary gears are gears of compact design, the special feature of which is that the fixed shafts (or shafts for torque transmission) are aligned with each other. Therefore, planetary gears are particularly advantageous for the converter according to the invention.

[0040] In a preferred embodiment, the planetary gear system used in the present invention comprises at least one ring gear (serving as sun gear) and several planet gears, the rotation axis of which is parallel to the rotation axis of the ring gear and supported by means of a carrier. The planet gears preferably rotate around the (inner) sun gear, wherein the sun gear shares the rotation axis of the ring gear and is parallel to the rotation axis of the planet gears. According to the present invention, the planetary gear system preferably operates in a so-called two-shaft mode, in particular a fixed transmission, i.e. the carrier is stationary and fixed in position, and the two sun gear shafts (in other words, the ring gear and the sun gear) rotate. Preferably, the planet gears and the (inner) sun gear are arranged inside the ring gear. This arrangement allows the planetary gear system to have an extremely compact design. Typically, there are 2 to 4 planet gears, in particular three planet gears per ring gear. The size is set preferably so that the planetary gear system converts the rotational movement of the ring gear into a faster rotation of the sun gear, with a gear ratio of about 1:4 to 1:10, in particular 1:5 to 1:8.

[0041] The generator is preferably arranged and configured so that the force (energy) transmitted by the planetary gear system is converted into electrical energy. It is further preferred that the planetary gear system (preferably its ring gear) is coupled to the shaft of the lever element and is particularly arranged directly between the shaft of the lever element and the generator. It is also preferred that the shaft of the lever element is connected to the ring gear, or preferably is integrally formed with the ring gear. The axes of the planetary gears are usually fixed, that is, they are directly or indirectly connected to the frame. The sun gear is preferably directly connected to the generator drive shaft, or even integrally formed with the generator drive shaft. By this arrangement, a preferred embodiment can be achieved, in which the planetary gear system converts the rotational movement of the shaft of the lever element into a faster rotation directed toward the generator, and the gear ratio is preferably approximately 1:4 to 1:10, in particular 1:5 to 1:8. In a particularly preferred embodiment, the planetary gear system is substantially integrated into the ring gear on the shaft or intermediate shaft of the lever element, which means that the planetary gear and the sun gear are substantially accommodated in the ring gear, and the ring gear is preferably part of the shaft or intermediate shaft of the corresponding lever element. Preferably, the coupling element of the mechanical coupling element system extends through the ring gear. This allows an extremely compact design of the mechanical coupling element system and the gearbox of the generator. In this case, it is preferred that the generator is arranged directly behind (ie directly adjacent to) the planetary gear system, in particular on the side opposite to the axis of the lever element.

[0042] The rotor of the generator is typically moved or driven via a system of mechanical coupling elements and a planetary gear, the stator of the generator being connected to the support element / rim of the wheel. As explained above, the carrier of the planetary gear supporting the planetary gear axis preferably forms the static part of the planetary gear. The axis of the sun gear then represents the axis on which the generator rotor is arranged.

[0043] All generators of the converter are preferably driven simultaneously in a coupled manner via a mechanical coupling element. This means that preferably all generators are driven via corresponding planetary gears arranged on the shafts of corresponding lever elements, wherein the shafts of the lever elements are frictionally connected via the mechanical coupling element system. In this case, the ring gear of the planetary gear system preferably forms part of the mechanical coupling element system, wherein the coupling element in particular extends through the ring gear.

[0044] Alternatively, the rotor of the generator moves via a direct connection to the intermediate shaft, for example, a connection element attached or coupled thereto, for example a connection wheel; the stator of the generator is connected to the support element / rim of the wheel. In this embodiment, the force of the lever element is transmitted to all intermediate shafts via a system of mechanical coupling elements and via these intermediate shafts to the generators, preferably simultaneously, and these generators are driven thereby.

[0045] For example, in order to enable the generator to be driven at a suitable speed even if the displacement of the lever element and therefore the movement of the mechanical coupling element system is relatively small, the converter has a planetary gear system. Where appropriate, preferably each generator can have an additional gearbox or transmission, which is configured to generate an additional limited transmission between the planetary gear system and the rotational movement of the generator rotor. For example, the gearbox and / or the transmission is configured to generate a transmission between the planetary gear system and the rotational movement of the rotor towards a higher speed of the rotor, in particular a transmission with a ratio greater than 1 to 1:4, preferably 1:2 to 1:3. However, it is preferred that the generator has no additional gearbox in addition to the planetary gear system.

[0046] In order to ensure a continuous movement of the mechanical coupling element and thus a power transmission, it is preferred that the one or more lever elements transmit the force to the shaft of the lever element via a freewheel clutch (i.e. a clutch that depends on the direction of rotation). Therefore, the converter preferably has a freewheel clutch for each lever element, which is configured for coupling according to the direction of rotation, i.e. has a coupling direction for producing an active coupling and an idling direction. Typically, the freewheel clutch is configured so that a friction connection occurs when the lever element moves towards the axis of rotation of the wheel, and correspondingly, idling occurs when the lever element moves away from the axis of rotation of the wheel. The lever element, the freewheel clutch, the mechanical coupling element system, the planetary gear system and the generator are preferably arranged and configured in such a way that the rotational movement of the lever element is transmitted via the freewheel clutch in the coupling direction via the mechanical coupling element system to the one or more rotors of the one or more generators and converted into electrical energy.

[0047] According to a further preferred embodiment, the converter according to the invention has a biasing means, in particular a spring, for the one or more lever elements, which biases the rotation of the lever element about its first end by means of a force in the rotational movement of the lever element, the force being caused by the deformation of the wheel tire due to contact with the road surface, i.e. in the direction of rotation of the lever element towards the wheel rotation axis. The biasing element ensures that the one or more lever elements are not in contact with the wheel tire when the wheel is at rest or when the wheel is only moving at a low speed, i.e. the one or more lever elements remain in a "retracted" state. The latter makes it easier to repair the wheel and change the tire on the wheel. The biasing means is then suitably configured so that, starting from an appropriate rotational speed of the wheel, a movement of the lever element away from the wheel rotation axis is allowed (the centrifugal force therefore exceeds the biasing force) and the contact element of the lever element can come into contact with the wheel tire. The biasing means is preferably configured so that, starting from a wheel rotation speed of at least 100 rpm, more preferably at least 120 rpm, a movement of the lever element away from the wheel rotation axis is allowed. A typical rotational speed is about 125 rpm, which corresponds to a speed of about 15 km / h (in a car).

[0048] In order to prevent the forces acting on the lever element from damaging the converter or its components due to excessive impact and / or excessive deformation of the wheel tread, corresponding protection mechanisms, in particular overload protection devices, are preferably provided. Preferably, the freewheel clutch, the clutch in or connected to the mechanical coupling element and / or the clutch connected to the generator is a safety clutch with overload protection, which allows rotation without effective coupling if a defined maximum force is exceeded.

[0049] The invention further relates to a system for obtaining electrical energy in a rolling wheel of a vehicle from the deformation of the wheel tyre due to contact with a road surface, said system comprising a converter as described above and a support element / wheel rim as a support structure. In a preferred embodiment, the lever element comprising the contact element does not protrude above the rim flange, i.e., does not protrude above the outer surface of the cylinder defined by the rim flange.

[0050] In one embodiment, the system has a converter as described above and a support structure, wherein the support structure is typically configured to hold the energy converter in a fixed arrangement around the center axis of the wheel. In particular, the support structure itself can be designed as a rim of the wheel or integrated therein, or the system has a rim (specially arranged in combination with the support structure) configured to receive the support structure in a fixed manner. The rim is preferably designed as one part.

[0051] According to a further embodiment, the system has a multi-part rim, which can simplify the installation of the converter or the support structure in the wheel. For example, the multi-part rim is designed as a two-part rim with a rim well and a rim sleeve, or as a three-part rim with a rim well, a rim sleeve and a rim star structure. In this case, the converter or the support structure and the multi-part rim can be configured, for example, so that the converter or the support structure is mounted on the rim well of the multi-part rim.

[0052] Finally, the invention relates to a land vehicle, preferably a motor vehicle or a truck, or a wheel comprising the above system. In one embodiment, the wheel comprises a wheel hub motor.

[0053] The present invention will now be described based on the accompanying drawings.

[0054] FIG. 1 shows a perspective view of a converter according to the invention with a system of lever elements and mechanical coupling elements on the rim.

[0055] FIG. 2 shows a perspective view of a converter according to the invention with a system of lever elements and mechanical coupling elements on the rim.

[0056] FIG. 3 shows a perspective view of a system of mechanical coupling elements, including a planetary gear system of a converter according to the invention.

[0057] FIG. 4 shows a perspective view of the planetary gears inside (A) and outside (C) the gears of the shaft.

[0058] FIG. 5 shows a perspective view through the shaft (B) of the lever element without the planetary gears.

[0059] FIG. 6 shows a schematic side view of a converter according to the invention with a lever element and a system of mechanical coupling elements on the rim.

[0060] FIG. 7 shows a cross section of a converter according to the invention having a lever element, a system of mechanical coupling elements, a planetary gear system and a generator.

[0061] FIG. 8 shows a perspective section through the shaft of the lever element, the system of mechanical coupling elements, the planetary gear system and the generator.

[0062] FIG. 9 shows a perspective view of a lever element including a contact element.

[0063] FIG. 10 shows a perspective view of a lever element including a contact element.

[0064] FIG. 11 shows the ratio of the distances of the axis of rotation N of the lever element from the wheel center M and the contact point K.

[0065] FIG. 12 shows three embodiments of the lever element.

[0066] The converter according to the invention is shown in FIG1 and comprises a lever element 1, which comprises a contact element 2 (in this case a roller), and a system of mechanical coupling elements 4. The converter is mounted on a wheel rim 7. The deformation of the tire (not shown) due to contact with the road surface causes the lever element 1 to partially rotate at its first end around the axis of rotation of the lever element and therefore around the shaft of the lever element, which rests on the inside of the tire via the contact element in the area of ​​contact with the road surface. The lever element 1 performs a "rocking movement" during operation. After passing through the deformation section of the tire due to its compression, the restoring force that returns the lever to the "extended" position is generated due to the centrifugal force of the wheel rotation. The lever element 1 is mounted on its shaft via a freewheel clutch, which ensures that the shaft rotates only in one direction, in particular when the lever element is pushed towards the axis of rotation of the wheel. This rotation of the shaft also turns the drive roller 18. The generated force is transmitted from the drive roller 18 to the adjacent roller via the coupling system 4 (in particular via the corresponding toothed belt 5). Each drive roller 18 and the adjacent rollers preferably carry two toothed belts, forming a "closed loop", which means that all axes of the lever elements are frictionally connected to the adjacent axes of the lever elements around the wheel by a mechanical coupling element system 4 using corresponding coupling elements 5. Three generators 6 are attached to a planetary gear system (not visible) respectively integrated into the drive rollers 18. The lever elements 1 and the generators 6 are arranged rotationally symmetrically around the axis of rotation of the wheel to avoid imbalance of the wheel. Due to the movement of a single lever element 1, all drive rollers 18 rotate, thereby also driving all three generators 6.

[0067] FIG2 shows a converter according to the invention similar to FIG1 , but in which the lever element 1 is in a retracted state (in other words, is shown folded over the rim 7), for example due to the limited effect of centrifugal forces when the wheel is stationary or rotating only at a low speed. When the influence of centrifugal forces is small, such as when the wheel is stationary or rotating only at a low speed, a return element (not shown, such as a return spring) causes the lever element to fold inwards, for example to allow changing a tire on the rim, or to avoid damage when driving over uneven terrain, such as a curb.

[0068] FIG3 shows a mechanical coupling element system 4, comprising a drive roller 18 on the shaft 9 of the lever element and a corresponding coupling element 5 (embodied here as a toothed belt). There are three embodiments of the shaft 9 and the corresponding drive roller 18: A, B and C. In embodiment A of the shaft, the planetary gear system 11 is arranged inside the drive roller 18. A generator (not shown) is driven via a generator shaft 17, which also forms the axis of the sun gear of the planetary gear system. Embodiment C of the shaft corresponds to embodiment A of the shaft, but without the planetary gear system 11, since usually not every drive roller 18 (for example only every fourth drive roller) is provided with a generator. Typically, every second drive roller 18 (as indicated in embodiment B of the shaft) is not equipped with a planetary gear, but is equipped with means for attaching (and possibly also tensioning) the coupling element 5 (in this case a toothed belt) when installed.

[0069] FIG. 4 shows a detail of a drive roller 18, which in embodiments A and C is located on the shaft 9 of the lever element (as depicted in FIG. 3 ). In an alternative embodiment of the converter according to the invention, the shaft can also represent an intermediate shaft 10 which does not carry a lever element. In embodiment A of the shaft, the planetary gear system 11 is arranged inside the drive roller 18. A generator (not shown) is driven via a generator shaft 17, which also forms the axis of the sun gear of the planetary gear system. Inside the roller 18, the ring gear 19 of the planetary gear system is firmly connected to the roller 18, and in some cases the roller 18 itself also forms the ring gear 19 of the planetary gear system. The axes of the planetary gears 20 are fixedly arranged on a carrier 22. The axis of the sun gear 21 of the planetary gear system is (integrally) formed as a generator drive shaft 17. Embodiment C of the shaft corresponds to embodiment A of the shaft, but without the planetary gear system 11, since usually only every fourth drive roller 18 is equipped with a generator.

[0070] FIG5 shows a detail of a drive roller 18 which, in embodiment B, is located on the shaft 9 of the lever element (as also depicted in FIG3 ). Instead of a planetary gear system, the roller 18 is equipped with means for attaching (and possibly also tensioning) the coupling element 5 (in this case a toothed belt) during its installation. For this purpose, the roller is preferably designed in two parts. The first part of the roller 18 holds the coupling element 5 (in this case designed as a toothed belt). The second part is attached separately to the first part of the roller and possibly also to the shaft 9, so that it is preferably added after the coupling element 5 is mounted on the first part of the roller 18. The second part of the roller 18 also carries the coupling element 5 (in this case designed as a toothed belt). Preferably, the arrangement of the rollers 18 in the converter alternates around the wheel, with embodiments A and C alternating and embodiment B in between. Thus, every second roller is embodiment B, equipped with means for attaching and possibly tensioning the coupling element (5) (in this case a toothed belt) during its installation. This configuration allows simple handling and proper tensioning of the toothed belt on the drive roller 18 of the converter according to the invention.

[0071] FIG6 shows a side view of a converter according to the invention, as shown in FIG2 , comprising a lever element 1 comprising a contact element 2, in this case a roller, and a mechanical coupling element system 4. The lever elements are shown in a retracted state, for example due to the limited influence of centrifugal forces when the wheel is stationary or rotating at a low speed, which means that they are folded over the rim 7. Also depicted is the mechanical coupling element system 4, which comprises a drive roller 18 and a corresponding coupling element 5, in this case designed as a toothed belt. The lever elements 1 and the generator 6 are arranged rotationally symmetrically around the rim 7 in order to avoid imbalance of the wheel. The angle α spanned by the axes of two adjacent lever elements 1 relative to the axis of rotation of the wheel is 360° / number of lever elements, in this case 360° / 12=30°.

[0072] FIG7 shows a section AA through the rim 7 and the converter according to the invention as indicated in FIG6 . The lever element 1 is mounted on the shaft 9 via a freewheel clutch 3 . This clutch transmits the rotational movement generated by the rocking movement of the lever element to the drive roller 18 and the corresponding coupling element 5 , which in this case is designed as a toothed belt. The rotation is gradually accelerated by the planetary gear system 11 and transmitted to the generator drive shaft 17 on the rotor 23 of the generator 6 .

[0073] FIG8 shows in perspective a section AA through the rim 7 and the converter according to the invention as indicated in FIG6 . The shaft 9 transmits the rotational movement generated by the rocking movement of the lever element to the drive roller 18 and the corresponding coupling element 5 (designed in this case as a toothed belt). The rotation is accelerated stepwise by the planetary gear system 11 and transmitted to the generator drive shaft 17 of the generator 6. Inside the drive roller 18, the planetary gear system 11 is provided for this purpose. Inside the roller 18, the ring gear 19 of the planetary gear is firmly connected to the roller 18, and in some cases the roller 18 itself forms the ring gear 19 of the planetary gear system. The axis of the planetary gear 20 is fixedly arranged on a carrier 22. The shaft of the sun gear 21 of the planetary gear system is (integrally) formed as the generator drive shaft 17. This shaft carries the rotor 23 of the generator. The stator 24 of the generator is connected to the rim 7.

[0074] FIG9 shows a detailed view of an embodiment of a lever element 1 with a contact element 2, in this case designed as a roller. The force is transmitted via the shaft 9 at the first end of the lever element 1 to the drive roller 18. The drive roller transmits the force to a mechanical coupling element (not shown). The freewheel clutch 3 transmits the movement of the lever element only in one direction of rotation; the overload protection device 12 ensures that no excessive forces are transmitted.

[0075] FIG10 shows a detailed view of an embodiment of a lever element 1 with a contact element 2, designed in this case as a roller. The force is transmitted via the shaft 9 at the first end of the lever element 1 to the drive roller 18. The drive roller then transmits the force to a mechanical coupling element (not shown). The freewheel clutch 3 transmits the movement of the lever element only in one direction of rotation; the overload protection device 12 ensures that no excessive forces are transmitted. A spring serves as a biasing element 13.

[0076] Figure 11 shows that the length A is the distance of the fulcrum N of the lever element from the wheel center M, and the length B is the distance of the fulcrum N of the lever element from the contact point K. The latter is the maximum distance of the contact element from the fulcrum N of the lever element, which makes or can make contact with the inside of the wheel tire.

[0077] 12 shows detailed views of three embodiments of a lever element 1 having one or more contact elements 2, in this case designed as rollers. In embodiment A, the lever element 1 supports a roller as contact element 2. In embodiment B, the lever element 1 supports a slide 14 (second part), which supports two rollers as contact elements 2. In embodiment C, the lever element 1 also supports a slide 14 (second part), which supports two rollers as contact elements 2. In embodiment C, the two rollers as contact elements 2 are surrounded by a belt 15, which is also guided to another roller (not shown) mounted on the slide.

[0078] List of reference numerals:

[0079] 1 Lever element

[0080] 2 Contact elements

[0081] 3 Freewheel clutch

[0082] 4 Mechanical connection component system

[0083] 5 Connecting elements

[0084] 6. Generator

[0085] 7 Rim

[0086] 8 Tires

[0087] 9 Lever element shaft

[0088] 10 Intermediate shaft

[0089] 11 Planetary gear system

[0090] 12 Overload protection device

[0091] 13 Biasing element

[0092] 14 Slide

[0093] 15 Strip on contact element

[0094] 16 Deflection roller

[0095] 17 Generator drive shaft

[0096] 18 Drive roller

[0097] 19 Planetary gear system ring gear

[0098] 20 Planetary Gear System Planetary Gear

[0099] 21 Planetary gear system sun gear

[0100] 22 Planetary gear system bracket

[0101] 23 Generator rotor

[0102] 24 Generator stator

Claims

1. A converter for obtaining electrical energy from a rolling wheel of a vehicle from the deformation of the wheel tire due to contact with a road surface, the converter comprising a) at least four lever elements (1) which are rotatably accommodated at their first end and are configured at their second end to come into contact with the inner side of a wheel tyre via at least one contact element (2), so that deformation of the wheel tyre due to contact with the road surface causes a rotational movement of the lever elements, b) a system of mechanical coupling elements (4) adapted to transmit the forces arising from the rotational movement of the lever element (1), and c) at least one generator (6) configured to convert the force transmitted by the mechanical coupling element system (4) into electrical energy, It is characterized in that The lever elements (1) are each pivotally mounted at their first end by means of a shaft (9), and the shaft (9) is configured to transmit the force of the rotational movement, The mechanical coupling element system (4) has at least two coupling elements (5) for each shaft (9) of each lever element (1), each of which is arranged to transmit the force of the rotational movement to the shaft (9) of an adjacent lever element (1) or to an intermediate shaft (10), and There is at least one planetary gear system (11) which is arranged to transmit the rotational movement of the shaft (9) of the lever element or the intermediate shaft (10) to the generator (6).

2. The converter according to claim 1, characterized in that The generator (6) is configured to convert the force transmitted by the planetary gear system into electrical energy.

3. The converter according to claim 1, characterized in that The planetary gear system is arranged such that it converts the rotational movement of the shaft (9) into a faster rotation directed towards the generator, the gear ratio preferably being approximately 1:4 to 1:

10.

4. A converter according to any one of the preceding claims, characterized in that The coupling elements (5) in the coupling element system (4) are arranged in such a way that they can bring about a friction connection of the shafts (9) of all lever elements (1) via an intermediate shaft (10).

5. A converter according to any one of the preceding claims, characterised in that The coupling elements (5) are each arranged in pairs in a rotationally symmetrical manner about the rotation axis of the wheel.

6. A converter according to any one of the preceding claims, characterised in that The coupling element (5) comprises a chain or a belt, in particular a toothed belt.

7. A converter according to any one of the preceding claims, characterised in that The lever element (1) is arranged rotationally symmetrically about the rotation axis of the wheel.

8. A converter according to any one of the preceding claims, characterised in that The converter has at least two generators (6) which are arranged rotationally symmetrically about the axis of rotation of the wheel.

9. A converter according to any one of the preceding claims, characterised in that The lever element (1) transmits force to the shaft (9) via a freewheel clutch (3).

10. A converter according to any one of the preceding claims, characterised in that The ratio ((A+B) / R) of the sum of the distance A from the fulcrum N of the lever element (1) to the center M of the wheel and the distance B from the fulcrum N to the contact point K between the contact element and the inner side of the wheel tire to the radius R of the inner side of the wheel tire is in the range of 102% to 110%, wherein, in the case where each lever element has multiple contact elements, the contact point is the contact point with the largest distance from the fulcrum N.

11. A converter according to any one of the preceding claims, characterised in that At the second end of the lever element (1), the contact element (2) is rotatably accommodated on the lever element around a rotation axis, so that the contact element (2) establishes contact between the lever element and the wheel tire, and the rotation axis of the contact element (2) extends essentially parallel to the rotation axis of the wheel, and the contact element (2) has a basically rotationally symmetrical shape with respect to rotation around its fulcrum and particularly represents a roller.

12. A converter according to any one of the preceding claims, characterised in that In terms of rotation, the contact element (2) can rotate freely around its fulcrum.

13. A converter according to any one of the preceding claims, characterised in that The converter also has a biasing device for the lever element (1), which uses the force in the rotational movement of the lever element caused by the deformation of the wheel tire due to contact with the road surface to bias the rotation of the lever element (1) around its first end.

14. A system for obtaining electrical energy in a rolling wheel of a vehicle from the deformation of the wheel tyre due to contact with a road surface, the system comprising a converter according to any of the preceding claims and a wheel rim as a supporting structure.

15. A vehicle or wheel comprising a system according to claim 14.

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