WHEEL GENERATOR WITH LEVER ELEMENTS WITH DOUBLE BEARING

Description

[0001] The present invention relates to a wheel generator, namely a converter for generating electrical energy in a rolling wheel of a vehicle from the deformation of the wheel tire due to contact with the road surface. Specifically, the present invention relates to a converter having the features of the preamble of claim 1. The present invention also relates to a system for generating electrical energy, as well as a vehicle or wheel comprising the system. State of the art

[0002] Vehicle tires, especially pneumatic tires, deform in the area of ​​the contact surface during rolling under load. This process causes the tire to flex, resulting in energy loss during power transmission due to heat buildup. The work performed in this process is called flexing energy.

[0003] The force required to flex the tire is a major component of rolling resistance and counteracts the driving force of a vehicle. On the one hand, increased flexing directly results in increased fuel and energy consumption of the vehicle and can also reduce the tire's service life. On the other hand, a certain amount of deformation of the tire and thus an increase in the tire's contact area on the ground is certainly desirable for increasing the vehicle's traction coefficient and also for improving ride comfort. Therefore, the air pressure in a pneumatic tire is typically adjusted as a compromise between flexing and vehicle traction.

[0004] Energy loss due to tire flexion is, along with aerodynamic drag, one of the main components of total energy loss in a vehicle. Therefore, especially in the field of electric vehicles, the development of recuperation systems (energy recovery, especially for supplying the vehicle battery) based on the utilization of tire flexion has been of interest for several years.

[0005] Various methods and systems for generating energy on or in the vehicle tire are known in the prior art, mainly for supplying various tire monitoring sensors arranged in the tire with electrical energy, for example tire pressure sensors.

[0006] For example, WO 2015 / 054763 A1 discloses a generator in a tire in which, by utilizing the slight deformation and reduction in space that occurs in the inner part of the tire between the wheel and the tire when it is in contact with the ground, a reciprocating movement is generated 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 the elastic deformation of the wheel between the driving plane and the wheel's center axis. The energy converter comprises a lever element with a cantilever mounted for rotation about a rotational axis. The lever element is configured for such an arrangement in a wheel for a vehicle that a deformation of the running surface toward the wheel's center axis generates a force acting on a contact surface of the cantilever, and the force acting on the contact surface causes a rotational movement of the cantilever in a pumping direction about the rotational axis.

[0008] However, in the converters known in the prior art, there is direct contact between the levers or arms, which are firmly connected to the rim, and the wheel tire. It has been shown that at higher speeds, possibly as low as approximately 50 km / h for a typical car tire, the direct contact between the levers and the wheel tire leads to significant heating of the tire material at the contact point, its softening and increased stickiness, resulting in tire damage and ultimately the failure of the generator.

[0009] US2004 / 0130157 A1 discloses a wheeled vehicle with mechanical, preferably hydraulic, pumps in its tires. The weight of the vehicle inflates a reservoir as the tires roll. The pressure in the reservoir is used to propel the vehicle directly or indirectly. The pumps are driven by brackets supporting rollers. These come into contact with specially designed beads on the inside of the tire.

[0010] In these prior art converters, the lever elements are arranged at an angle significantly less than 45° to the tire's inner surface. This reduces the forces generated by the levers' direct contact with the tire's inner surface at the contact point. However, it also reduces the effective deflection of the lever elements, i.e., the angular range they cover during their movement.

[0011] WO 2022 / 167214 A1 discloses a converter for generating electrical energy in a rolling wheel of a vehicle from the deformation of the wheel rim due to contact with the road surface, which converter does not have these problems of the prior art and thus ensures, in particular, more reliable operation even at higher speeds with high efficiency. This is achieved by a contact element, for example a roller, being mounted on the second end of the lever element so that it can rotate about a rotation axis on the lever element such that the contact element mediates contact between the lever element and the wheel rim. This enables compensation for the relative movement of the lever element with respect to the inner surface of the tire, thus significantly reducing wear and stress on the tire.

[0012] However, under more demanding conditions, particularly at higher speeds, increasing wear on the inside of the tire has been observed. Without wishing to be bound by any particular theory, it is assumed that the frequent rapid changes in direction of rotation of the roller, particularly due to the inertia of the roller, lead to slippage of the roller relative to the inside of the tire. When the lever element begins to collapse due to the flexing of the tire, the direction of rotation of the roller is opposite to that of the lever element. In contrast, the direction of rotation of the lever element is reversed when it extends. It is assumed that this rapid change of direction, which occurs particularly at higher speeds, disrupts the contact between the roller and the inside of the tire and causes slippage. This latter leads to increased wear on the inside of the tire. Disclosure of the invention

[0013] It is an object of the present invention to provide a converter for generating electrical energy in a rolling wheel of a vehicle from the deformation of the wheel tire due to contact with the road surface, which converter does not have the problems of the prior art, in particular ensures reliable operation even at higher speeds with high efficiency and is as compact as possible.

[0014] This object is achieved according to the present invention with a converter for generating electrical energy in a rolling wheel of a vehicle from the deformation of the wheel tire due to contact with the road surface, comprising at least one lever element which is rotatably mounted at its first end and is configured at its second end to come into contact with the inside of a wheel tire via at least one contact element in such a way that a deformation of the wheel tire due to contact with the road surface causes a rotational movement of the lever element, at the second end of the lever element the contact element is rotatably mounted on the lever element by means of a bearing about a rotation axis in such a way that the contact element mediates the contact of the lever element with the wheel tire, and the rotation axis of the contact element runs substantially parallel to the rotation axis of the wheel, and at least one electrical generator which is configuredto convert the force generated by the rotational movement of the lever element into electrical energy, wherein the bearing comprises an intermediate ring, a first rolling bearing and a second rolling bearing such that the intermediate ring is connected to the second end of the lever element via the first rolling bearing, and the intermediate ring is connected to the contact element via the second rolling bearing.

[0015] During its flexing motion, the wheel rim performs a non-linear movement with respect to the rim. This means that, based on the rim as the reference system, the movement of a defined part of the wheel rim that comes into contact with the road surface does not follow a straight line during one wheel revolution, but rather describes a surface. During one wheel revolution, there is a relative movement between the corresponding contact surface of the wheel rim and the roller of the lever that comes into contact, with the relative direction of rotation between the roller and the lever changing rapidly. The invention is based on the discovery that in known converters, the levers or arms, which are firmly connected to the rim, have direct contact with the interior of the wheel rim, causing the roller of the lever to slip, resulting in friction and consequently strong local heat generation.

[0016] According to the invention, it has now surprisingly been found that this problem can be solved by means of a special bearing provided between the roller and the lever element. According to the invention, this bearing has an intermediate ring, a first rolling bearing and a second rolling bearing such that the intermediate ring is connected to the second end of the lever element via the first rolling bearing, and the intermediate ring is connected to the contact element via the second rolling bearing. This is therefore a double, nested bearing comprising two rolling bearings. The intermediate ring acts as a connecting link and is in contact with both the lever element and the contact element, preferably a roller, via a separate rolling bearing. The lever element and the contact element are therefore not in direct contact, but only via the intermediate ring. The latter is therefore rotatable relative to both the lever element and the roller.In other words, even with a fixed lever element and fixed roller, the intermediate ring remains rotatable. It is assumed that due to the additional degree of freedom of rotation (compared to the intermediate ring) and possibly also reduced inertia, the roller can perform faster changes of direction, or is less prone to slipping relative to the inside of the tire due to the rapid counter-rotational changes of the lever element.

[0017] The invention will now be described in further detail with reference to preferred embodiments.

[0018] The converter according to the invention for generating electrical energy in a rolling wheel of a vehicle from the deformation of the wheel tire due to contact with the road surface comprises at least one lever element that is rotatably mounted at its first end and configured at its second end to contact the inside of the wheel tire via at least one contact element such that deformation of the wheel tire due to contact with the road surface causes a rotational movement of the lever element. The wheel typically comprises a rim and a wheel tire that can be filled with compressed air.

[0019] The rotational movement of the lever element is typically understood to mean a partial rotation (pivoting movement) of the lever element about the axis of rotation N at the first end. The lever element is therefore specifically designed to detect deformations of the wheel tire in the region of the contact surface that occur during the rolling process of the loaded wheel rolling on a substantially flat driving plane by means of the contact element and to translate these deformations into a rotational movement about the axis of rotation N at the first end of the lever element. The lever element therefore has no contact with the inside of the tire, but is only in contact with it via the at least one contact element. According to one embodiment of the converter, this 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 inside of the tire of the wheel.

[0020] Each lever element is rotatably mounted at its first end, preferably on the support structure or the rim of the wheel. In principle, the axis of rotation N at the first end of the lever element can have any direction that runs essentially parallel to its corresponding contact surface on the inside of the wheel tire, since the flexion movement of the inside of the wheel tire, i.e., a movement toward the rim, can thus lead to a partial rotation of the lever element. In a preferred embodiment, the axis of rotation of the lever element runs essentially parallel to the axis of rotation of the wheel.

[0021] In the context of the present invention, substantially parallel preferably means a deviation from the parallel of less than 10°, more preferably less than 5°.

[0022] In a preferred embodiment, the lever element is one-piece. In this case, it preferably carries one, in particular only one, contact element which is rotatably mounted thereon. In an alternative, equally preferred embodiment, the lever element is at least divided into two parts, i.e. it consists of at least two, preferably only two, parts which are mechanically connected and preferably partially rotatable relative to one another. For example, the first part of the lever element forms the first end, on which the lever element is rotatably mounted, and the second part represents the second end which carries the contact element(s). The partial rotatability of the first part relative to the second part allows the rotational movement (rocking movement) of the lever element to be compensated for when the contact elements come into contact with the inside of the tumbled tire, while at the same time maintaining contact between the contact elements and the inside of the tire.In this alternative embodiment, the lever element, preferably each lever element, preferably carries at least two, in particular only two, contact elements that are rotatably mounted on the lever element, in particular the second part. Particularly preferably, in the alternative embodiment, the lever element thus consists of a first part with the first end, and the second part, which represents a holding element for at least two, preferably two contact elements, and thus preferably represents a roller carriage. The latter is configured such that both contact elements can come into contact with the inside of the wheel rim (surface of the inside of the tire) simultaneously. In this way, the contact area on the inside of the wheel rim can be increased, and thus the point force and thus the point load on the wheel rim can be reduced.The second part (hereinafter also referred to as the "slide") is mounted on the lever element in such a way that it can rotate partially, so that when the lever element is "folded out," e.g., from the rest position, contact of all contact elements carried by the slide with the wheel tire is possible. In a preferred embodiment, the distance between the axes of rotation of the contact elements carried by the (each) slide is approximately equal (±10%, preferably ±5%) to the distance between the axes of rotation of two adjacent contact elements of second (immediately) adjacent lever elements when the contact elements are in contact with the inside of the wheel tire. For example, the distance between the axes of rotation of second contact elements, which each of the slides of the preferably 8 or 12 lever elements carries, is preferably approximately equal (±10%, preferably ±5%) to the distance between the axes of rotation of a contact element of a first slide and the axis of rotation of the nearest contact element of the (immediately) adjacent slide.In other words, the angle β spanned by the two axes of rotation of the contact elements of a carriage relative to the axis of rotation of the wheel is preferably approximately 360° / 2*n, where n is the number of lever elements or carriages. The angle β spanned by the two axes of rotation of the contact elements of a carriage relative to the axis of rotation of the wheel is therefore approximately (±10%, preferably ±5%) half the angle α between two lever elements. The angle α is the angle spanned by the axes of rotation of two adjacent lever elements (as in the . Figure 9shown), that is, with the lever elements in the same position, the axes of rotation of the carriages also span relative to the axis of rotation of the wheel. The angle α thus corresponds to 360° / n, where n is the number of lever elements. In this embodiment, the force is distributed evenly across the wheel rim (surface of the inside of the tire), since the contact elements contact the wheel rim at approximately the same distance. With 12 lever elements and two rollers per carriage, 24 contact elements are in contact with the inside of the tire at approximately the same distance (±10%, preferably ±5%) (the angle β between adjacent contact elements, both between two contact elements of a carriage and between the adjacent contact elements of two adjacent carriages, is then approximately 15° (±10%, preferably ±5%)).Contact elements that are approximately equally and therefore evenly spaced across the inside of the tire also lead to a more even energy transfer to the lever elements, since in typical flexion deformations, for example of car or truck tires, at least two lever elements always experience a deflection via their slides at the same time.

[0023] In one embodiment, the preferably two contact elements of a carriage, preferably when designed as rollers, are spanned or rotated by a belt or band. The belt or band runs, for example, directly around both rollers, or additionally around a deflection roller, which can also be arranged on the carriage. The spanned contact elements, preferably rollers, come into contact with the inside of the tire via the belt or band. This increases the effective contact area of ​​the contact elements with the inside of the tire and thus reduces the point load and thus the stress on the tire. The belt can be designed, for example, as a V-belt or V-ribbed belt to prevent it from running off the rollers.

[0024] In a preferred embodiment, the converter has at least six lever elements, in particular at least 6 to 16, most preferably 8 to 12.

[0025] In a preferred embodiment, the converter has the lever elements arranged rotationally symmetrically around the rotation axis of the wheel, in particular at least 6 to 16, most preferably 8 to 12.

[0026] 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 deformation of the wheel tire due to contact with the road surface causes a (partial) rotational movement of the lever element. This means that the (each) lever element has at least one contact element at its second end, rotatably mounted in or on the lever element in such a way that the contact element mediates contact between the lever element and the wheel tire.

[0027] According to the invention, the contact element is rotatably mounted on the second end of the lever element by means of a bearing. This means that the bearing is fastened on the one hand to the second end of the lever element and on the other hand to the contact element. The bearing enables the contact element to rotate relative to the lever element. According to the invention, the bearing has an intermediate ring, a first rolling bearing and a second rolling bearing such that the intermediate ring is connected to the second end of the lever element via the first rolling bearing, and the intermediate ring is connected to the contact element via the second rolling bearing. In other words, the bearing has at least two rolling bearings which are connected via an intermediate ring. The axes of rotation of the bearings are preferably the same, i.e. they lie on top of one another. The two rolling bearings, i.e. the first and the second, are not directly connected.Rolling bearings are bearings in which, in contrast to the lubrication in plain bearings, rolling bodies reduce frictional resistance between an inner ring and an outer ring. According to the invention, the intermediate ring is thus connected to at least the inner ring or the outer ring of the first rolling bearing and to the inner ring or the outer ring of the second rolling bearing, or is implemented as such. Preferably, the intermediate ring is connected to the inner ring of the second rolling bearing and the outer ring of the first rolling bearing, or is implemented as such. In this embodiment, when the outer ring of the second rolling bearing (which is preferably fastened to the contact element) and the inner ring of the first rolling bearing (which is preferably fastened to the lever element) are fixed, the intermediate ring remains rotatably mounted and can rotate independently of the lever and contact element.During rapid changes in the direction of rotation of the lever and contact element, the intermediate ring thus allows an additional degree of rotational freedom without increasing the inertia of the contact element, as it can rotate independently of it. The experimental setup has shown that the use of the inventive "double bearing," i.e., the combination of the first and second rolling bearings with an intermediate ring, can reduce slippage, i.e., the loss of contact between the contact element and the tire's inner surface.

[0028] In a preferred embodiment, the first rolling bearing and the second rolling bearing are designed as roller bearings or ball bearings, preferably ball bearings. Suitable roller bearings or ball bearings are known in the art and commercially available, e.g. from Schäffler KG (FAG) or SKF. Preferably, the first rolling bearing and the second rolling bearing each comprise at least two cylindrical roller bearings or deep groove ball bearings spaced apart with respect to the rotational axis of the contact element. A cylindrical roller bearing or deep groove ball bearing usually comprises a cage and a set of rolling elements. Usually, a bearing used to support an axle, in this case a rolling bearing, comprises two, or possibly more, cylindrical roller bearings or deep groove ball bearings, for example two sets of cages and rolling elements. These can be arranged next to one another or at a distance from one another, with a spaced-apart arrangement increasing the stability of the mounted axle.

[0029] Preferably, the first rolling bearing and the second rolling bearing are arranged substantially within the contact element, preferably substantially within each other. This means that, according to the invention, the inner ring and the outer ring of the first (inner) rolling bearing are preferably arranged within the contact element (i.e., within the cylinder defined by the outer surface of the contact element).

[0030] In a preferred embodiment, the first rolling bearing comprises two deep groove ball bearings W1a and W1b and the second rolling bearing comprises two deep groove ball bearings W2a and W2b, and the arrangement of the deep groove ball bearings, seen along the common rotation axis Q, is W1a - W2a - W2b - W1b, see Figure 4 .

[0031] In a preferred embodiment, the difference between the radii of the first rolling bearing and the second rolling bearing is less than 50%, more preferably less than 20%, in particular less than 10%. The radius of the bearing is understood to be the radius of the outer edge of the outer ring relative to the bearing's rotational axis, i.e., usually half the outer diameter of the bearing.

[0032] The intermediate ring is a component that rotates around the rotational axis Q of the bearing and is suitable for being connected at least to the inner ring or the outer ring of the first rolling bearing and to the inner ring or the outer ring of the second rolling bearing. If one of the rolling bearings, e.g. the first rolling bearing, comprises two deep groove ball bearings W1a and W1b and / or the second rolling bearing comprises two deep groove ball bearings W2a and W2b, the intermediate ring preferably connects a pair of deep groove ball bearings, for example W1a with W2a and W1b with W2b. For this purpose, the intermediate ring can be designed in one piece or in two parts. Typically, the intermediate ring is arranged within the contact element (i.e. within the cylinder spanned by the outer surface of the contact element).

[0033] In a further preferred embodiment of the converter, the (each) lever element does not come into direct contact with the inside of the wheel tire at any position of rotation about its axis of rotation N at its first end (during normal operation), i.e., it does not touch it. Rather, only the contact element(s) come into contact with the inside of the wheel tire, i.e., touches it, provided that the lever element has rotated accordingly about the axis of rotation at the first end towards the tire surface (away from the rim). The axis of rotation N of the contact element(s) is substantially parallel to the axis of rotation M of the wheel. If more than one contact element is present on a lever element, their axes of rotation are arranged parallel.The possibility that the contact element is, on the one hand, rotatably mounted on the lever element and, on the other hand, can rotate about an axis that is essentially parallel to the axis of rotation of the wheel, makes it possible to compensate for the relative movement between the wheel rim and the lever element, thus minimizing friction between the wheel rim and the lever element. Preferably, the contact element is, with regard to its dimensions, at least in the area that comes into contact with the inside of the wheel rim, essentially rotationally symmetrical with respect to its axis of rotation. In particular, it is therefore a roller or partial roller (roller segment). The roller is essentially cylindrical (the axis of rotation of the contact element then corresponds to the cylinder axis), optionally with a circular, outwardly curved cylinder surface (barrel-shaped roller).Typical suitable radii of the contact element, i.e. preferably roller radii, are those in which the ratio of the radius of the contact element to the radius of the inside of the wheel rim R (around the wheel center) is in the range from 0.04 to 0.08, preferably 0.05 to 0.07. Typical suitable roller radii, in particular for a car tire, are therefore in the range from 18 mm to 30 mm. The contact element is preferably freely rotatable with respect to its axis of rotation, in particular freely rotatable through 360°. This means that the contact element can preferably rotate freely around the axis of rotation around which it is rotatably mounted and fastened on / in the lever element or in the carriage, in particular completely around its own axis. This ensures uniform contact between the contact element and the inside of the wheel rim during operation, even at higher speeds.

[0034] According to a preferred embodiment, the ratio of the distance A of the axis of rotation of the lever element N from the wheel center M to the wheel of the inside of the wheel tire R (A / R) is in the range of 0.55 to 0.65, preferably 0.56 to 0.63, in particular 0.58 to 0.62.

[0035] According to a preferred embodiment, the ratio of the distance B of the rotational axis of the lever element N from the contact point K of the contact element with the inside of the wheel rim (in the case of several contact elements per lever element, the one with the greatest distance from the rotational axis N) to the radius of the inside of the wheel rim R (B / R) is in the range from 0.44 to 0.55, preferably 0.45 to 0.53, in particular 0.46 to 0.50.

[0036] In the converter according to the invention, the lever element, which is rotatably mounted at its first end, can contact the inner side of the wheel rim via the at least one contact element. This means that the sum of the distance A of the rotational axis of the lever element N from the wheel center M and the distance B of the rotational axis N from the contact point K of the contact element with the inner side of the wheel rim (in the case of multiple contact elements per lever element, the contact point is the one with the greatest distance from the rotational axis N) (A+B) is greater than the radius of the inner side of the wheel rim R ((A+B) / R)>1).

[0037] Preferably, the deflection of the lever elements, i.e. the angular range they cover during their movement, is significantly increased by the sum (A+B) of the distance A of the axis of rotation N of the lever element from the wheel center M and the distance B of the axis of rotation N from the contact point K of the contact element with the inside of the wheel rim, in the case of multiple contact elements per lever element, the contact point with the greatest distance from the axis of rotation N, in relation to the radius of the inside of the wheel rim R ((A+B) / R)) being in the range of 102% to 112%, preferably in the range of 103% to 110%, in particular 104% to 107%. This value range for (A+B) / R means a significantly more "stretched" arrangement of the lever elements compared to the prior art, so that they are arranged almost perpendicular to the inside of the tire.Although this increases the forces and the relative movement between the wheel rim and the lever element, it enables a high level of efficiency, since only by increasing the angular range covered by the lever elements during their movement can an effective drive of the generators be ensured.

[0038] The radius R always refers to the radius of the unloaded tire from the wheel center to the inside of the tire (the surface of the tire's inner side). The rotation axis of the lever element N refers to the rotation axis of the lever element at its first end.

[0039] The converter according to the invention preferably further comprises a mechanical coupling element system. This is typically configured and suitable for transmitting the force (energy) arising from the rotational movement of the lever elements, preferably to the generator(s). The mechanical coupling element system typically comprises at least two coupling elements per shaft of each lever element. Typical suitable coupling elements are gears and axles, belts, chains, and the like. Preferably, the coupling element comprises at least one chain or belt, in particular toothed belts and / or V-ribbed belts. The mechanical coupling element system typically also comprises corresponding means for the engagement of the coupling elements on the shafts of the lever elements, e.g., gears, grooved wheels, and the like.

[0040] Preferably, the force (energy) of all lever elements of the converter is transmitted to the (common) mechanical coupling element system, for example, a set of chains or belts, in particular toothed belts and / or V-ribbed belts. The mechanical coupling element system preferably comprises at least two coupling elements per shaft of each lever element, wherein all shafts of the lever elements are non-positively connected by the mechanical coupling element system to the adjacent shafts of the lever elements or via intermediate shafts via a coupling element each. Since the lever elements are preferably arranged rotationally symmetrically around the wheel's axis of rotation, i.e., in a ring shape, a "ring connection" is preferably created, i.e., all shafts of the lever elements are non-positively connected by the mechanical coupling element system to the adjacent shafts of the lever elements via a coupling element each.The number of coupling elements in the mechanical coupling element system therefore preferably corresponds to the number of shafts of the lever elements. This means that intermediate shafts are preferably not present.

[0041] The mechanical coupling element system thus enables the frictional connection of all lever elements of the converter. This allows for more continuous drive of the generator(s). Preferably, the mechanical coupling element system is also frictionally connected to several, most preferably all, generators of the converter. By distributing the total energy generated by the lever elements across several generators, these can be operated continuously, allowing for efficient energy recovery with minimal material consumption.

[0042] In a preferred embodiment, the converter thus comprises a mechanical coupling element system which, via belts, in particular V-belts, toothed belts, or V-grooved belts, establishes the frictional connection between all lever elements, preferably 8 or in particular 12, of the converter and all generators, preferably three, four, or six. It is preferred that a belt is guided around a roller or gear connected to the shaft of a lever element and around a roller or gear connected to the shaft of an adjacent lever element. In one embodiment, one or more intermediate freewheel rollers or rollers on intermediate shafts may be provided, which are connected via coupling elements. Preferably, no intermediate freewheel rollers or rollers that are not connected to a shaft of a lever element and / or only to a generator are provided.In the most preferred embodiment, the converter thus comprises a mechanical coupling element system that comprises 12 belts, in particular V-belts, toothed belts or V-groove belts, which effect the frictional connection of all shafts of the 12 lever elements.

[0043] Finally, the converter according to the invention comprises at least one electrical generator configured to convert the force (energy) generated by the rotational movement of the lever element(s), preferably transmitted through the mechanical coupling element system, into electrical energy. In a preferred embodiment, the converter has at least two generators arranged rotationally symmetrically around the rotational axis of the wheel, in particular at least 2 to 12, most preferably 3 to 8, for example three or four. Preferably, the number of lever elements corresponds to a multiple of the number of generators.

[0044] According to the invention, at least one planetary gear is preferably present, which is arranged to transmit the rotary movement of a shaft of a lever element to an electric generator. Planetary gears, also referred to in the prior art as epicyclic gears, are gear or friction gears which, in addition to shafts fixed to the frame, also have axes that rotate on circular paths within the frame. Accordingly, a distinction is made between the central or sun gears mounted on the axes fixed to the frame and the epicyclic, planetary, or star gears mounted on the rotating axes. The star gears rotating on the rotating axes orbit a central wheel in much the same way as planets orbit the sun. The web, which carries the rotating axes, in turn rotates about an axis fixed to the frame. Suitable planetary gears and, in particular, suitable materials for the planetary gear used according to the invention, e.g., stainless steel, are known in the prior art.Planetary gears are compact transmissions with the special feature that the frame-mounted axes (or shafts for torque transmission) are aligned. Therefore, the planetary gear is particularly advantageous for the converter according to the invention.

[0045] In a preferred embodiment, the planetary gear used according to the invention comprises at least one ring gear (as a central gear) and several epicyclic gears whose axes of rotation are parallel to the axis of rotation of the ring gear and which are supported by a web. The epicyclic gears preferably rotate around an (inner) sun gear, the latter dividing the axis of rotation of the ring gear, which is parallel to the axes of rotation of the epicyclic gears. According to the invention, the planetary gear is preferably used in so-called two-shaft operation, specifically as a stationary transmission, i.e. the web is stationary and fixed, and the two central gear shafts, i.e. the ring gear and the sun gear, rotate. The epicyclic gears and the (inner) sun gear are preferably arranged within the ring gear. This latter arrangement enables an extremely compact design of the planetary gear. Typically, there are 2 to 4 epicyclic gears, in particular three epicyclic gears per ring gear.The dimensioning is preferably such that the planetary gear translates the rotational movement of the ring gear towards the sun gear into high speed, preferably with a ratio of approximately 1:4 to 1:10, in particular 1:5 to 1:8.

[0046] The electric generator is preferably arranged and configured such that the force (energy) transmitted by the planetary gear is converted into electrical energy. It is further preferred that the planetary gear, preferably its ring gear, is coupled to a shaft of a lever element, and in particular is arranged directly between the shaft of a lever element and the generator. It is also preferred that the shaft of the lever element is connected to the ring gear or is formed as such, preferably in one piece. The axes of the planetary gears are typically fixed, i.e. directly or indirectly connected to the rim. The sun gear is preferably directly connected to the generator drive shaft or even formed as such.This arrangement enables such a preferred embodiment in which the planetary gear system rapidly translates the rotary movement of the shaft of the lever element to the generator, preferably with a ratio of 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 of the lever element or an intermediate shaft, i.e., the planetary gears and the sun gear are preferably located substantially within the ring gear, which is preferably part of the shaft of the corresponding lever element or an intermediate shaft. The coupling elements of the mechanical coupling element system preferably run via the ring gear. This enables an extremely compact design of the mechanical coupling element system and the transmission for the generator. The generator is preferably located directly after, i.e.adjacent to the planetary gear, in particular on the side facing away from the shaft of the lever element.

[0047] Typically, the generator rotor is moved or driven via the mechanical coupling element system and the planetary gear system, while the generator stator is connected to the carrier element / rim of the wheel. Preferably, as explained above, the planetary gear carrier, which supports the axes of the planetary gears, forms the static part of the planetary gear system. The axis of the sun gear then represents the axis on which the generator rotor is mounted.

[0048] Preferably, all generators of the converter are driven simultaneously via the mechanical coupling element system. This means that all generators are preferably driven via corresponding planetary gears arranged on the shafts of corresponding lever elements, with the shafts of the lever elements being frictionally connected via the mechanical coupling element system. Preferably, the ring gears of the planetary gears form part of the mechanical coupling element system; in particular, coupling elements run via the ring gears.

[0049] Alternatively, the generator rotor is moved via direct coupling to intermediate shafts, for example, a connecting element attached or coupled to them, such as a connecting wheel. The generator stator is connected to the carrier element / rim of the wheel. In this embodiment, the force of the lever elements is transmitted through the mechanical coupling element system to all intermediate shafts, and via these to the generators, preferably all generators simultaneously, thereby driving them.

[0050] So that the electric generator can be driven at suitable speeds, for example by relatively small deflections of a lever element and thus small movement of the mechanical coupling element system, the converter preferably has the planetary gear. If necessary, a further gear or a transmission, preferably per generator, can be present to generate an additional defined transmission ratio between the planetary gear and the rotational movement of the rotor of the generator. For example, the gear and / or the transmission is configured to generate a transmission ratio between the planetary gear and the rotational movement of the rotor towards higher speeds of the rotor, in particular a transmission ratio with a ratio greater than 1 to 1:4, preferably 1:2 to 1:3. However, preferably no further gear is present for the generator besides the planetary gear.

[0051] To ensure continuous movement and thus power transmission of the mechanical coupling element system, it is preferred that the lever element(s) transmit the power via a one-way clutch, i.e., a clutch dependent on the direction of rotation, for example, to the shaft of the lever element. Thus, the converter preferably has one one-way clutch per lever element, configured for a clutch dependent on the direction of rotation, i.e., having a clutch direction for establishing an active clutch and a freewheeling direction. Typically, the one-way clutch is configured such that the frictional connection occurs when the lever element moves toward the wheel's axis of rotation, and correspondingly, freewheeling occurs when the lever element moves away from the wheel's axis of rotation.The lever element, the one-way clutch, the mechanical coupling element system, the planetary gear and the electric generator are preferably arranged and configured such that the rotational movement of the lever element is transmitted via the one-way clutch in the coupling direction via the mechanical coupling element system to the rotor(s) of the electric generator(s) and converted into electrical energy.

[0052] According to a further preferred embodiment, the converter according to the invention comprises a preloading means for the lever element(s), in particular a spring, which biases the rotation of the lever element about its first end with a force toward the rotational movement of the lever elements caused by the deformation of the wheel tire due to contact with the road surface, i.e., toward the rotation of the lever element toward the wheel's rotational axis. The preloading element ensures that the lever element(s) are not in contact with the wheel tire when the wheel is stationary or at only low wheel speeds, i.e., they remain in a "retracted" state. This simplifies wheel repair and tire replacement on the wheel.The preloading means is then expediently configured such that, at suitable wheel speeds, movement of the lever element away from the wheel's rotational axis is permitted (i.e., the centrifugal force exceeds the preload force), and the contact element of the lever element can come into contact with the wheel tire. Preferably, the preloading means is configured such that, at wheel speeds of at least 100 rpm, more preferably at least 120 rpm, movement of the lever element away from the wheel's rotational axis is permitted. Typical speeds are approximately 125 rpm, which corresponds to a speed of approximately 15 km / h (for a car).

[0053] To prevent excessive impacts and / or excessive deformation of the wheel's running surface from damaging the converter or its components due to forces acting on the lever element, a corresponding protective mechanism, particularly overload protection, is preferably provided. For example, the overrunning clutches, the clutches within or to the mechanical coupling element system, and / or the clutches to the generators are preferably safety clutches with overload protection, which allow rotation without effective coupling when defined maximum forces are exceeded.

[0054] The present invention further relates to a system for generating electrical energy in a rolling wheel of a vehicle from the deformation of the wheel rim due to contact with the road surface, comprising a transducer as described above and a support element / wheel rim as the support structure. In a preferred embodiment, the lever elements, including contact elements, do not protrude beyond the rim flanges, i.e., beyond the lateral surface of a cylinder defined by the rim flanges.

[0055] In one embodiment, the system comprises 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 the rim of the wheel or integrated into it, or the system comprises a rim—specifically intended for combination with the support structure—configured for fixedly receiving the support structure. Preferably, the rim is a single piece.

[0056] According to a further embodiment, the system comprises 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 spider. In this case, the converter or the support structure and the multi-part rim can be configured, for example, such that the converter or the support structure is mounted on a rim well of the multi-part rim.

[0057] Finally, the present invention relates to a land vehicle, preferably a motor vehicle or a truck, or a wheel comprising a system as described above. In one embodiment, the wheel also comprises a rim motor.

[0058] The invention will now be described with reference to the drawings. Figure 1shows a perspective view of a converter according to the invention with unfolded lever elements on a rim. Figure 2 shows a perspective view of a converter according to the invention with folded lever elements on a rim. Figure 3 shows a schematic side view of a section of a converter according to the invention and the interaction of the lever elements with the wheel tire. Figure 4 shows a section along the section line AA from Figure 3 by the contact element on the wheel tire. Figure 5 shows a schematic side view of the double bearing according to the invention consisting of an outer and inner bearing. Figure 6 shows a perspective view of a mechanical coupling element system including the planetary gears of a converter according to the invention. Figure 7 shows a perspective view of a planetary gear inside (A) and outside (C) the gear of a shaft. Figure 8shows a perspective section through a shaft (B) of a lever element without planetary gear. Figure 9 shows a schematic side view of a converter according to the invention with lever elements on a rim. Figure 10 shows a section through a converter according to the invention with lever elements, the mechanical coupling element system, the planetary gear and the generator. Figure 11 shows a perspective section through a shaft of a lever element, the mechanical coupling element system, the planetary gear and the generator. Figure 12 shows a perspective view of a lever element including contact element. Figure 13 shows a perspective view of a lever element including contact element. Figure 14 illustrates the relationships between the distances of the rotation axis of the lever element N from the wheel center M and the contact point K. Figure 15 illustrates three embodiments of a lever element.

[0059] A converter according to the invention is Figure 1shown, which comprises lever elements 1 including contact elements 2, here rollers, as well as a mechanical coupling element system 10. The converter is mounted on a rim 7. Due to the deformation of the tire (not shown) due to contact with the road surface, the lever elements 1, which rest on the inside of the tire in the area of ​​contact with the road surface via the contact element, are partially rotated around the axis of rotation of the lever element at their first end, and thus around the shaft of the lever element. During operation, the lever elements 1 thus perform a "rocking motion." The restoring force to the "stretched" state, after passing through the part of the tire deformed by the flexion of the tire, results from the centrifugal force due to the rotation of the wheel. The lever elements 1 are attached to their shaft via a freewheel clutch, whereby the shaft rotates in only one direction, namely when the lever element is pressed towards the axis of rotation of the wheel.The resulting force is transmitted to the adjacent rollers via the coupling element system 10, in particular via the respective toothed belts. Each drive roller, and also the adjacent rollers, preferably carry two toothed belts each, thus creating a "ring connection," i.e., all shafts of the lever elements are non-positively connected to the adjacent shafts of the lever elements by the mechanical coupling element system 10 via a coupling element each. Three generators 4 are attached to planetary gears (not visible) integrated into the drive rollers. The lever elements 1 and the generators 4 are arranged rotationally symmetrically around the wheel's rotational axis to prevent wheel imbalance. The movement of a lever element 1 rotates all drive rollers, and thus also drives all generators 4.

[0060] Figure 2 shows a converter according to the invention according to Figure 1 However, the lever elements 1 are shown in the retracted state, for example due to insufficient influence of centrifugal force when stationary or at only a low rotational speed of the wheel, i.e. folded against the rim 7. If the influence of centrifugal force when stationary or at only a low rotational speed of the wheel is minimal, a return element (not shown), for example a return spring, causes the folding in, for example to enable a tire change on the rim, or to avoid damage when driving over uneven terrain, such as a curb.

[0061] Figure 3shows a section of a converter according to the invention, which comprises lever elements 1 including contact elements 2, here rollers. The converter is mounted on a rim 7. Due to the deformation of the tire 8 as illustrated (undeformed tire is indicated by dashed lines) due to contact with the road surface, the lever elements 1, which rest on the inside of the tire 8 in the area of ​​contact with the road surface via the contact element, are partially rotated about the axis of rotation of the lever element at their first end, and thus about the shaft of the lever element. During operation, the lever elements 1 thus perform a "rocking motion." When the vehicle moves in the direction of travel B, i.e., the tire rotates in the direction of rotation C, the lever elements 1, which are in contact with the inside of the tire via the contact element 2, are rotated from position P1, here clockwise as indicated for position P1. From approximately position P2, i.e.From approximately the maximum rotation of the lever elements, they begin to extend again due to centrifugal force, rotating in the opposite direction—in this case, counterclockwise. The rapid changes in rotation direction between lever element 1 and contact element 2 must be compensated for by the bearing used according to the invention (not shown here).

[0062] Figure 4 shows a section along the section line AA from Figure 3by the contact element 2 and the bearing 3 according to the invention. According to the invention, the bearing 3 has an intermediate ring 3a, a first rolling bearing 5 and a second rolling bearing 6 such that the intermediate ring 3a is connected to the second end of the lever element 1 via the first rolling bearing 5, and the intermediate ring 3a is connected to the contact element 2 via the second rolling bearing 6. In other words, the bearing 3 has two rolling bearings 5, 6 which are connected via an intermediate ring 3a. The axes of rotation Q of the bearings lie on top of one another. The two rolling bearings 5, 6 are not connected directly, but via the intermediate ring 3a. The intermediate ring 3a is connected to the inner ring 6b of the second rolling bearing and the outer ring 5a of the first rolling bearing.In the embodiment shown, when the outer ring 6a of the second rolling bearing, which is fastened to the contact element 2, and the inner ring 5b of the first rolling bearing, which is fastened to the lever element 1, are fixed, the intermediate ring 3a remains rotatably mounted and can rotate independently of the lever and contact element. The two rolling bearings 5 ​​and 6 each comprise two deep groove ball bearings, here the first rolling bearing W1a and W1b and the second rolling bearing W2a and W2b, and the arrangement of the deep groove ball bearings, seen along the common axis of rotation Q, is W1a - W2a - W2b - W1b. During the rapid changes of direction of rotation of the lever element 1 and contact element 2, as in . Figure 3As explained, the intermediate ring 3a thus allows an additional degree of freedom of rotation without increasing the inertia of the contact element 2, since it can rotate independently of it. The experimental setup has shown that the use of the "double bearing" according to the invention, i.e., the combination of the first and second rolling bearings with an intermediate ring, can reduce slippage, i.e., the loss of contact between the contact element and the tire's inner surface.

[0063] Figure 5shows a section perpendicular through the contact element 2 along the lever element 1 through the bearing 3 according to the invention. The bearing 3 has the intermediate ring 3a, the first rolling bearing 5, and the second rolling bearing 6 such that the intermediate ring 3a is connected to the second end of the lever element 1 (via the central fastening) via the first rolling bearing 5, and the intermediate ring 3a is connected to the contact element 2 via the second rolling bearing 6. The two rolling bearings 5, 6 are not connected directly, but via the intermediate ring 3a. The intermediate ring 3a is connected to the inner ring 6b of the second rolling bearing and the outer ring 5a of the first rolling bearing. In the embodiment shown, when the outer ring 6a of the second rolling bearing, which is fastened to the contact element 2, and the inner ring 5b of the first rolling bearing, which is fastened to the lever element 1, are fixed, the intermediate ring 3a remains rotatably mounted and can rotate independently of the lever and contact element.

[0064] Figure 6shows a mechanical coupling element system 10, comprising the drive rollers 18, which are located on the shafts 9 of the lever elements, as well as corresponding coupling elements 10a, here designed as toothed belts. The shafts 9 and the corresponding drive rollers 18 come in three designs A, B and C. In the design of shaft A, a planetary gear 11 is provided inside the drive roller 18. A generator (not shown) is driven via the generator shaft 17, which also forms the axis of the sun gear of the planetary gear. The design of shaft C corresponds to that of shaft A, but without planetary gear 11, since typically not every drive roller 18 has a generator, e.g. only every fourth drive roller 18.Typically, every second drive roller 18, as indicated in the design of the shaft B, is equipped with means for fastening and possibly also for tensioning the coupling elements 10a, here toothed belts, when the latter are placed on, instead of with a planetary gear.

[0065] Figure 7 shows details of the drive roller 18, which are located on the shafts 9 of the lever elements, in versions A and C, according to Figure 3In an alternative embodiment of the converter according to the invention, the shafts can also represent intermediate shafts 9a that do not carry a lever element. In the design of shaft A, a planetary gear 11 is provided inside the drive roller 18. A generator (not shown) is driven via the generator shaft 17, which also forms the axis of the sun gear of the planetary gear. Inside the roller 18, the ring gear 19 of the planetary gear is fixedly connected to the roller 18; if necessary, the roller 18 itself also forms the ring gear 19 of the planetary gear. The axes of the planetary gears 20 are fixedly arranged on the web 22. The shaft of the sun gear 21 of the planetary gear is designed (in one piece) as the generator drive shaft 17. The design of shaft C corresponds to that of shaft A, but without planetary gear 11, since typically only every fourth drive roller 18 has a generator provided.

[0066] Figure 8shows details of the drive roller 18, which is located on the shaft 9 of a lever element, in version B, as well as in Figure 6Instead of the planetary gear, the roller 18 is equipped with means for fastening and possibly also for tensioning the coupling elements 10a, in this case a toothed belt, when the latter is placed on top. For this purpose, the roller is preferably designed in two parts. The first part of the roller 18 carries a coupling element 10a, here designed as a toothed belt. The second part is separately fastened to the first part of the roller and possibly also to the shaft 9, so that it can preferably be attached after the coupling element 10a has been placed on the first part of the roller 18. The second part of the roller 18 also carries a coupling element 10a, here designed as a toothed belt. The arrangement of the rollers 18 in the converter is preferably arranged around the wheel as versions A and C alternating, with a version B in between.Thus, every second roller is of design B, which is equipped with means for fastening and possibly also for tensioning the coupling elements 10a, in this case, toothed belts, when the latter are applied. This enables easy application of the toothed belts with appropriate tension to the drive rollers 18 of the converter according to the invention.

[0067] Figure 9 shows a converter according to the invention as in Figure 2shown in side view, comprising lever elements 1 including contact elements 2, here rollers, as well as a mechanical coupling element system 10. The lever elements are shown in the retracted state, for example due to insufficient influence of centrifugal force when stationary or at only a low rotational speed of the wheel, i.e. folded against the rim 7. Also shown is the mechanical coupling element system 10 comprising the drive rollers 18 and corresponding coupling elements 10a, here designed as a toothed belt. The lever elements 1 and the generators 4 are arranged rotationally symmetrically around the rim 7 in order to prevent an imbalance of the wheel. The angle α that two shafts of two adjacent lever elements 1 span with respect to the axis of rotation of the wheel is 360° / number of lever elements, here 360° / 12 = 30°.

[0068] Figure 10 shows the section AA, as in Figure 9indicated by the rim 7 and the converter according to the invention. The lever element 1 is attached to the shaft 9 via the overrunning clutch 25. This transfers the rotation generated by the rocking movement of the lever element to the drive roller 18 and corresponding coupling elements 10a, here designed as a toothed belt. The rotation is translated into high-speed via the planetary gear 11 to the generator drive shaft 17 on the rotor 23 of the generator 4.

[0069] Figure 11 shows a section of section AA, as in Figure 9indicated by the rim 7 and the converter according to the invention in a perspective view. The shaft 9 transmits the rotation generated from the rocking movement of the lever element to the drive roller 18 and corresponding coupling elements 10a, here designed as a toothed belt. The rotation is translated into speed via the planetary gear 11 to the generator drive shaft 17 of the generator 4. A planetary gear 11 is provided for this purpose inside the drive roller 18. Inside the roller 18, the ring gear 19 of the planetary gear is firmly connected to the roller 18; if necessary, the roller 18 itself forms the ring gear 19 of the planetary gear. The axes of the planetary gears 20 are fixedly arranged on the web 22. The shaft of the sun gear 21 of the planetary gear is designed (in one piece) as the generator drive shaft 17. The latter carries the rotor 23 of the generator. The stator 24 of the generator is connected to the rim 7.

[0070] Figure 12shows a detailed view of an embodiment of a lever element 1 with a contact element 2, here designed as a roller. The force is transmitted to the drive roller 18 via the shaft 9 at the first end of the lever element 1. The latter transfers the force to the mechanical coupling elements (not shown). The overrunning clutch 25 transmits the movement of the lever element in only one direction of rotation, and the overload protection 12 ensures that excessive forces are not transmitted.

[0071] Figure 13shows a detailed view of an embodiment of a lever element 1 with a contact element 2, here designed as a roller. The force is transmitted to the drive roller 18 via the shaft 9 at the first end of the lever element 1. The latter transmits the force to the mechanical coupling elements (not shown). The overrunning clutch 25 transmits the movement of the lever element in only one direction of rotation, and the overload protection 12 ensures that excessive forces are not transmitted. A spring serves as a preload element 13.

[0072] Figure 14 illustrates the length A as the distance of the rotational axis of the lever element N from the wheel center M and the length B as the distance of the rotational axis of the lever element N from that of the contact point K. The latter is the greatest distance of the contact element from the rotational axis of the lever element N that comes or can come into contact with the inside of the wheel tire.

[0073] Figure 15shows detailed views of three embodiments of lever elements 1 with contact element(s) 2, here designed as a roller. In embodiment A, the lever element 1 carries a roller as contact element 2. In embodiment B, the lever element 1 carries a carriage 14 (second part) which carries two rollers as contact elements 2. In embodiment C, the lever element 1 also carries a carriage 14 (second part) which carries two rollers as contact elements 2. In embodiment C, the two rollers as contact elements 2 are spanned by a belt 15, which is guided over another roller (not shown) mounted on the carriage. Reference character list:

[0074] 1 Lever element 2 Contact element 3 Bearing 3a Intermediate ring 4 Generator 5 First rolling bearing 5a Outer ring of the first rolling bearing 5b Inner ring of the first rolling bearing 6 Second rolling bearing 6a Outer ring of the second rolling bearing 6b Inner ring of the second rolling bearing 7 Rim 8 Tire 9 Shaft Lever element 9a Intermediate shaft 10 Mechanical coupling element system 10 Mechanical coupling element 11 Planetary gear 12 Overload protection 13 Pre-tensioning element 14 Carriage 15 Belt on contact elements 16 Deflection pulley 17 Generator drive shaft 18 Drive pulley 19 Planetary gear ring gear 20 Planetary gear planetary gear 21 Planetary gear sun gear 22 Planetary gear web 23 Generator rotor 24 Generator stator 25 Overrunning clutch

Claims

1. Transducer for obtaining electrical energy in a rolling wheel of a vehicle from the deformation of the wheel's tire by contact with the carriageway, comprising a) at least one lever element (1) which is rotatably mounted at its first end and at its second end is configured to come into contact with the inside of a tire by means of at least one contact element (2) such that a deformation of the tire due to contact with the carriageway causes a rotational movement of the lever element, b) at the second end of the lever element (1) the contact element (2) is rotatably mounted about an axis of rotation on the lever element by means of a bearing (3) such that the contact element (2) facilitates the contact of the lever element with the tire, and the axis of rotation of the contact element (2) runs substantially parallel to the axis of rotation of the wheel, and c) at least one electrical generator (4) configured to convert the power generated by the rotational movement of the lever element (1) into electrical energy, characterized in that the bearing (3) has an intermediate ring (3a), a first rolling bearing (5) and a second rolling bearing (6) such that the intermediate ring (3a) is connected to the second end of the lever element (1) by means of the first rolling bearing (5), and the intermediate ring (3a) is connected to the contact element (2) by means of the second rolling bearing (6).

2. Transducer according to claim 1, characterized in that the first rolling bearing (5) and the second rolling bearing (6) are designed as roller bearings or ball bearings.

3. Transducer according to claim 1 or 2, characterized in that the first rolling bearing (5) and the second rolling bearing (6) each comprise at least two cylindrical roller bearings or grooved ball bearings spaced apart with respect to the axis of rotation of the contact element (2).

4. Transducer according to one of the preceding claims, characterized in that the intermediate ring (3a), the first rolling bearing (5) and the second rolling bearing (6) are arranged within the contact element (2) .

5. Transducer according to one of the preceding claims, characterized in that the difference in the radii of the first rolling bearing (5) and of the second rolling bearing (6) is less than 10%.

6. Transducer according to one of the preceding claims, characterized in that the contact element (2) has a shape substantially rotationally symmetrical with respect to rotation about its axis of rotation, and in particular represents a roller.

7. Transducer according to one of the preceding claims, characterized in that the contact element (2) is freely rotatable with respect to rotation about its axis of rotation, in particular is freely rotatable through 360° about its axis of rotation.

8. Transducer according to one of the preceding claims, characterized in that the transducer has at least two lever elements (1) arranged rotationally symmetrically about the axis of rotation of the wheel.

9. Transducer according to one of the preceding claims, characterized in that the transducer has at least two electrical generators (4) arranged rotationally symmetrically about the axis of rotation of the wheel.

10. Transducer according to one of the preceding claims, characterized in that the transducer further has a mechanical coupling element system (10), which is suitable for transmitting the power generated by the rotational movement of the lever element(s) (1) and the electrical / electrical generator (s) (4) is / are configured to convert the power transmitted by the mechanical coupling element system (10) into electrical energy.

11. Transducer according to claim 10, characterized in that all the lever elements (1) transmit the power to a common mechanical coupling element system (10) comprising mechanical coupling elements (10a).

12. Transducer according to claim 10 or 11, characterized in that the mechanical coupling element system (10) is configured such that it can transmit the power experienced by the lever elements (1) to all electrical generators (4).

13. Transducer according to one of the preceding claims 11 or 12, characterized in that the coupling element (10a) is a chain or a belt, in particular a toothed belt.

14. System for obtaining electrical energy in a rolling wheel of a vehicle from the deformation of the tire by contact with the carriageway, comprising a transducer according to any one of the preceding claims and a wheel rim as a support structure.

15. Vehicle or wheel comprising a system according to claim 14.