Three-Wheeled Vehicle With Multipart Frame

Abstract

A vehicle, such as a cargo bike, may include a multipart frame, a single wheel, and a wheel pair which comprises two mutually spaced wheels, where the single wheel is connected to a first frame part of the frame, and the two wheels of the wheel pair are rotatably mounted on a second frame part of the frame about a common axis. The first frame part and the second frame part may be connected by at least one joint and can be rotated relative to each other about a pivot axis defined by the at least one joint, and the pivot axis may run through a contact point of the single wheel.

Description

BACKGROUND AND SUMMARY

The invention relates to a three-wheeled vehicle, in particular a cargo bike, which has a multi-part frame, in particular a frame divided into two, the frame parts thereof being connected by at least one joint, and the at least one joint thereof defining a pivot axis about which the frame parts are pivotable relative to one another, or mutually pivotable, respectively.

Cargo bikes nowadays, and against the background of new concepts and solutions for individual mobility being required, are becoming ever more popular. Therefore, a multiplicity of implementations relating to these cargo bikes and to three-wheeled vehicles in general are already known in the prior art.

For example, there are two-wheeled and three-wheeled cargo bikes, wherein in the case of three-wheeled cargo bikes a pair of wheels having two wheels may be disposed at the front or the rear. Such cargo bikes, or generally such three-wheeled vehicles, include not only purely pedal-driven bikes but likewise e-bikes which support the mechanical drive by an electric drive, but also other three-wheeled vehicles which are exclusively motor-driven, for example.

However, cargo bikes, bicycles or e-bikes having a plurality of wheels are typically long, heavy and difficult to steer. In particular when a load is additionally being carried it may arise that this load, as a moving mass, acts on the vehicle and counteracts the steering movements, which may lead to critical or even dangerous and uncontrollable steering maneuvers and thus to accidents.

Apart from the difficult steering, the frame can be set in vibration by the moving mass during load reversals, which over time can be detrimental to the stiffness and stability of the frame such that the frame may break.

It follows from this disadvantageous behavior, which is unexpected for many drivers, that the cargo bikes, or three-wheeled vehicles, respectively, that are known in the prior art cannot be intuitively operated by drivers who are used to a customary bicycle. Accordingly, many drivers require some initial familiarization and training before the cargo bikes can be safely driven, or before the cargo bikes are to be driven in traffic.

In the case of bicycles having two wheels, or a pair of wheels, at the front, complex axle steering is required in some instances. Variants of cargo bikes having two wheels, or a pair of wheels, at the rear, such as conventional rikshaws, for example, are often of a rigid embodiment such that the frame of the bicycle cannot lean into the curve.

However, there are also variants of three-wheeled vehicles in which the entire frame, or at least part thereof, and in particular the front part of the frame, is laterally pivotable and, as a result, can lean into the curve when cornering, this being fundamentally intended to enable a more ergonomic and more dynamic driving style and also corresponding to the behavior of a “normal” bicycle.

Such vehicles, having an at least partially pivotable frame, are known from documents DE 10 2014 113 710 A1, DE 10 2016 115 803 A1, EP 3 205 564 B1, DE 10 2016 120 697 B4, FR 3 020 335 B1, JP 5995434 B2, KR 10-1197628, US 3 605 929 A, US 6 104 154 A, and WO 2011/107674 A1, for example, which are each hereby incorporated by reference in their entireties.

However, the pivoting in the known solutions, as a result of the respective superstructure, leads to lateral forces potentially engaging on the front wheel when leaning into the curve, the front wheel by these forces being steered out its track such that the front wheel is offset in relation to its previous track relative to the pair of wheels on the rear axle (the rear wheels), this having a negative effect on the steering behavior.

Moreover, a lever action as a result of the pivoting is often generated on the front wheel, as a result of which the latter is pushed downward while negotiating curves, this increasing the probability of the frame, or the pivotable front part of the frame, tilting. This lever action, or the force caused by the lever action, respectively, is moreover dependent on the payload such that the behavior of the vehicle can vary heavily as a function of the payload, or as a function of the moving masses, respectively, this adding to the unpredictability of the vehicle.

Therefore, in at least one aspect, the invention is based on the object of overcoming the aforementioned disadvantages and of providing a three-wheeled vehicle which has a driving behavior similar to that of a conventional bicycle and makes it possible to lean into curves.

This object is achieved by the combination of features according to the claims.

Proposed according to the invention is a vehicle, in particular a cargo bike, which has a multi-part frame, preferably a two-part frame, a single wheel, and a pair of wheels. Apart from a cargo bike which is operated purely by muscular power, inter alia three-wheeled e-bikes, purely electrically driven three-wheeled vehicles or hybrid solutions are also understood to be such a vehicle which is three-wheeled on account of the single wheel and the pair of wheels. A single wheel is in particular understood to be a singular wheel, wherein a plurality of wheels that substantially act as one wheel may also represent a single wheel, this being the case, for example, when these wheels are embodied as a twin wheel, or the spacing between the wheel or tire contact faces, respectively, is very minor and below 5 cm, for example. The pair of wheels has in particular two wheels which are mutually spaced apart in a transverse direction of the vehicle. The single wheel is connected to a first frame part of the multi-part frame, and the two wheels of the pair of wheels are mounted on a second frame part of the frame so as to be rotatable about a common axis. The connection between the single wheel and the first frame part is preferably embodied by way of an intermediate element, such as a wheel fork, for example, such that the single wheel, in particular as the front wheel, is fixed to the first frame part with the wheel fork and with the latter is pivotable about a steering axis. Accordingly, the single wheel is assigned to the first frame part, and the pair of wheels is assigned to the second frame part. It is furthermore provided that the first frame part and the second frame part are connected by at least one joint and are mutually rotatable, or able to be twisted or pivoted, respectively, about a pivot axis defined by the at least one joint, such that the first frame part can thus be moved relative to the second frame part about the pivot axis. According to the invention, the pivot axis runs through a contact point of the single wheel. Since wheels in an ideal case, which at best is absent in reality, contact a hard surface or the carriageway only at a single one-dimensional point, the contact point, which may also be referred to as the wheel contact point, is not understood to be only a one-dimensional point but rather also the contact area, or an idealized contact point of the single wheel within the contact area, on a carriageway or a hard surface.

As a result of the pivot axis running through the contact point, a rotation of the single wheel during pivoting of the frame parts takes place about the contact point such that no track offset and no leverage arise. As a result, riding without holding the handlebars is also possible, for example. As a result of the rear structure, or the rear or second frame part, respectively, being decoupled from the pivot axis, the weight of a load bearing on the second frame part is neither steered nor does the latter lean into the curve, so that these masses do not act as a moving mass and have no negative effect on the behavior of the front or first frame part, or the driving behavior of the vehicle, respectively.

The pivot axis preferably runs in a symmetry plane of the vehicle, or in a symmetry plane of the frame, or at least of the first frame part, respectively.

As has been mentioned above, the single wheel is preferably a front wheel which on a wheel fork is connected to the first frame part so as to be pivotable about a steering axis. Accordingly, the wheels of the pair of wheels form the rear wheels of the vehicle. Since the contact point forms the lowest point of the single wheel, or front wheel, respectively, the pivot axis, proceeding from the rear of the vehicle, slopes downward in the direction of the front wheel.

One advantageous refinement provides that the first frame part and the second frame part are connected by at least two joints which are disposed so as to be mutually spaced apart on the pivot axis. While the frame parts are preferably connected exclusively by the joints, and/or devices for the transmission of torque or control devices, such as chains, brake cables, electrical lines or the like, for example, can extend between the frame parts. A first joint of the two joints is a ball joint, a radial bearing or an elastomer element which is in particular flexible and reversibly deformable. Furthermore, a second j oint of the two joints is a ball j oint, a radial bearing or an elastomer element which is likewise in particular flexible and reversibly deformable. This gives rise to various advantageous combinations. For example, the first and indeed the second joint can in each case be a ball joint, in each case be a radial bearing, or in each case be an elastomer element, wherein hybrid forms in which the first joint is an elastomer element and the second joint is a ball joint, for example, are also possible. Elastomer elements moreover have the advantage that the latter not only permit pivoting but at the same time also absorb impacts and shocks and transmit the latter less intensely to the vehicle frame.

In order for the profile of the pivot axis to be able to be adjusted, for example when replacing the wheel of the single wheel or in any other situation that displaces the contact point in relation to the pivot axis, in one particularly advantageous refinement the position of the first joint and/or of the second joint in relation to the first frame part and/or the second frame part is adjustable. The position, or the respective position, of the joint is preferably adjustable in the horizontal direction, or in the height direction in terms of the vehicle, and/or in the vertical direction or in the longitudinal direction in terms of the vehicle, respectively, such that, as a result of a corresponding adjustability of the position, or as a result of a corresponding displacement capability of the joints, respectively, the pivot axis can be displaced or rotated to a profile that intersects the contact point.

As an alternative to an embodiment which has two, or at least two, joints, a variant in which the first frame part and the second frame part are connected by exactly one joint formed by at least one radial bearing is likewise advantageous. While a plurality of radial bearings and/or axial bearings may be disposed in the preferably exactly one joint, the latter is distinguished in that the joint forms a single and preferably encapsulated module. As a result, the bearings of the joint are comparatively close to one another such that the forces cannot be absorbed in an optimal manner, but other advantages such as, for example, improved protection in relation to contamination, a more compact construction and simplified assembling are indeed derived owing to the improved encapsulation.

In order to be able to adjust the angle in the case of a single joint that permits pivoting about the pivot axis, and as a result to be able to adjust the profile of the pivot axis through the contact point, it is furthermore preferably provided that the angle of the single joint is adjustable in relation to the first frame part and/or the second frame part, the joint per se or the joint by a corresponding device thus being configured to be twisted about a transverse axis of the vehicle.

In order to prevent the vehicle or the first frame part from falling over when stationary, or to prevent a dangerous inclination of the first frame part in relation to the second frame part during travel, a further design embodiment provides that the vehicle furthermore comprises a delimiting device which is configured to restrict a rotatability of the first frame part in relation to the second frame part about the pivot axis, or to restrict the rotatability to a pre-defined angular range. Such a delimiting device can be, for example, also a simple stand which can be folded out when the vehicle is stationary and supports the first frame part in relation to the ground. Alternatively, a fixing device which when the vehicle is stationary can be disposed so as to rigidly connect the first frame part to the second frame part such that the frame parts can no longer rotate or pivot in relation to one another when stationary, can likewise be considered. Apart from such devices which are suitable only for the stationary vehicle, further alternatives which restrict a rotatability of the joints and as a result also restrict pivoting of the frame parts can also be considered.

A further alternative design embodiment provides that the vehicle furthermore comprises a restoring device which is configured to rotate or pivot the first frame part, from a position deflected in relation to a pre-defined central position, back to the central position. The central position here preferably corresponds to a resting position in which the first frame part and the second frame part are situated when traveling straight ahead without a steering input, or are in each case completely upright, respectively. Such a restoring device can be implemented by springs, for example, or else gas struts. In particular when an elastomer element is provided as one of the joints, the elastomer element can integrally form the delimiting device and/or the restoring device. Moreover, such a restoring device can complement or entirely replace a delimiting device, because the restoring device generates a restoring moment by way of which the frame, or the frame parts, respectively, are mutually aligned even when stationary.

The vehicle furthermore preferably has at least one drive device which generates a torque and is a motor, for example, or a pedal mechanism which is operated by muscular force. The drive device is disposed on the first frame part or directly on the single wheel and is configured to transmit the torque to the single wheel. Alternatively, the drive device is disposed on the second frame part or directly on one of the wheels of the pair of wheels and configured to transmit the torque to at least one of the wheels of the pair of wheels. Accordingly, the variants provide that the transmission of torque from the drive device to the respective driven wheel or the respective driven pair of wheels does not take place by way of the separating plane between the frame parts but directly in the region of one of the frame parts. Such a drive device can moreover also be provided as a wheel hub motor, for example, so that the drive device can also be disposed directly in a wheel hub of the single wheel or in one of the wheels of the pair of wheels, for example. If the rear wheels, or the wheels of the pair of wheels, respectively, are to be driven, the drive device can be configured as a central rear or mid-mounted motor, wherein the torque between the wheels of the pair of wheels can be split and controlled by way of a torque-splitting device (torque vectoring).

Additionally or alternatively, the vehicle may furthermore have at least one optional second drive device which generates a torque and in turn can be a motor or else a device for driving by muscular force. The drive device is disposed on the first frame part and is configured to transmit the torque to at least one of the wheels of the pair of wheels by way of a torque transmission device. Alternatively, the drive device is disposed on the second frame part and configured to transmit a torque to the single wheel by way of the torque transmission device. In this variant, it is thus provided that the transmission of torque by the corresponding device takes place across the separating plane between the frame parts, wherein the torque transmission device is preferably configured to permit pivoting or twisting of the frame parts about the pivot axis without being damaged, respectively.

A further variant provides that one drive device drives the single wheel as well as at least one of the wheels of the pair of wheels, wherein the transmission of torque in this instance takes place with at least one device suitable for this purpose.

The vehicle can also be provided with a serial hybrid drive in which a generator driven by muscular force generates current, for example, which with corresponding lines is transmitted across the separating plane between the frame parts to an electric drive device, the latter driving at least one of the wheels.

The torque transmission device in a particularly advantageous variant is a prop shaft which, at least in the region of a dividing plane between the first frame part and the second frame part that is defined by the at least one joint, extends from the first frame part to the second frame part so as to be coaxial with the pivot axis. Since the prop shaft is thus coaxial with the pivot axis, the prop shaft remains substantially unaffected by the mutual pivoting of the frame parts. For example, if a single joint is provided, the prop shaft can extend through the joint.

Apart from a classic, rigid prop shaft, which is distinguished in particular by universal joints, a flexible or elastic shaft may also be used as an alternative.

Alternatively, the torque transmission device, in the case of a likewise advantageous configuration, is a chain drive which has a chain and of which the chain permits and compensates a twisting about the pivot axis, or of which the chain is configured to permit and compensate a twisting about the pivot axis at least within a pre-defined range, respectively. For this purpose, a chain guide and/or a chain tensioner, by way of which it is ensured that the chain does not jump from the associated sprockets while the frame parts are pivoted, can preferably be provided.

For example, the mechanical transmission of force, or the transmission of torque, respectively, can take place in a manner optimized in terms of force, and in a simple and cost-effective manner by means of a bicycle chain which enables torsion between a front chainring on the first frame part and a rear sprocket on the second frame part of at least 45°, and has to be guided in each case only at the top and the bottom on the front chainring and on the rear sprocket in order to prevent the chain from jumping off.

The features disclosed above can be combined in any suitable manner to the extent that this is technically possible and the features are not mutually contradictory.

BRIEF DESCRIPTION OF THE FIGURES

Other advantageous refinements of the invention are illustrated in more detail in the claims and specification, including hereunder in conjunction with the description of the preferred embodiment of the invention by means of the figures. In the figures:

FIGS. 1a, 1b show a first vehicle variant in a lateral view and a plan view from above;

FIGS. 2a, 2b show a second vehicle variant in a lateral view and a plan view from above;

FIGS. 3a, 3b show a third vehicle variant in a lateral view and a plan view from above;

FIG. 4a shows a view of a single wheel in the central position and deflected positions of a vehicle variant according to the invention;

FIG. 4b shows a view of a single wheel in the central position and deflected positions of a vehicle of the prior art;

FIGS. 5a-e show in each case a drive configuration of a vehicle variant.

The figures are schematic in an exemplary manner. The same reference signs in the figures refer to identical or similar functional and/or structural features.

DETAILED DESCRIPTION OF THE DRAWINGS

FIGS. 1a to 3b show in total three variants of a vehicle 1, in each case in a lateral view and in a plan view from above.

The vehicle variants use in each case dissimilar joints 21, 22, 23 in order to configure a pivot axis X about which a first frame part 14 is pivotable in relation to a second frame part 15 of a vehicle frame, wherein the pivot axis X runs in each case through a contact point A of the single wheel 11 configured as the front wheel on or with the ground B, respectively.

Since the joint 23, or the joints 21, 22, is/are in each case disposed in a rear region, or on a rear region of the vehicle 1, respectively, and define a separating or dividing plane between the first, or the front, frame part 14 and the second, or the rear, frame part 15, respectively, this results in a profile of the pivot axis X that slopes downward from the rear toward the front and intersects the contact point A of the single wheel 11.

For the sake of improved orientation in the figures, a coordinate system or axis system, respectively, which identifies the respective axes is illustrated both in FIGS. 1a to 3b and in FIGS. 4a to 5e. The coordinate system, which refers to the vehicle, defines the longitudinal axis L of the vehicle, the height axis H of the vehicle, and the transverse axis Q of the vehicle.

Since a cargo bike is in each case illustrated as an exemplary embodiment of a vehicle 1 according to the the embodiments of FIGS. 1a to 3b, the front wheel, or the single wheel 11, respectively, is mounted in each case on a wheel fork 16 and by way of the wheel fork 16 is connected to the first or the front frame part 14 so as to be rotatable about a steering axis. For the sake of simplification, the wheel fork 16 can be considered to be part of the first frame part 14.

A pedal drive or pedal mechanism, as is also known from conventional bicycles, is in each case provided as the drive device 31 for driving the vehicle 1 in FIGS. 1a to 3b. Accordingly, a gearshift can also be provided, for example. Provided for transmitting a torque from the drive device 31, which is operated by muscular force, to at least one of the wheels 11, 12, 13 is presently a torque transmission device 34 which is configured as a chain drive or chain gear, respectively, such that the torque from the drive device 31 is thus transferred to an axle which runs between the wheels 12, 13 of the pair of wheels by means of a chain running via sprockets, the rear wheels, thus the wheels 12, 13 of the pair of wheels, being equally driven by the axle in the examples illustrated in FIGS. 1a to 3b.

Since a chain which spans the dividing plane between the frame parts 14, 15 is provided in the variants according to FIGS. 1a to 2b, a chain tensioner is furthermore shown in the figures, by way of which a pre-defined or adequate chain tension is maintained even when the chain is torsioned while tilting the frame parts 14, 15. Moreover, a guide installation for guiding the chain can preferably be provided.

This is only an exemplary drive configuration, wherein further configurations are possible, for example according to FIGS. 5a to 5e.

It is furthermore to be established that the rear, or the second frame part 15, respectively, in the variants shown in FIGS. 1a to 3b, and moreover also in the embodiment according to FIG. 5e, is configured as an integral, substantially rectangular structure (in the plan view from above) which is configured as the load carrier, on which the loads which are to be transported by the cargo bike can thus be disposed directly, or for example by way of a receptacle (not illustrated) such as a platform, a basket or seats, on the second frame part 15.

In the variant according to FIGS. 1a and 1b the pivotability, or rotatability, respectively, of the front or first frame part 14 in relation to the rear or second frame part 15, the latter being supported in relation to the ground by way of the wheels 12, 13 that are spaced apart in the transverse direction Q of the vehicle, is implemented by two single joints 21, 22 which are mutually spaced apart along the pivot axis X. The further the single joints 21, 22 are spaced apart along the pivot axis X, the better the forces acting between the frame parts 14, 15 can be absorbed. To this end, even further single joints may be provided. The two single joints 21, 22 presently are configured as a ball joint or a ball head joint, respectively, which have been known for a long time in the prior art and the construction of which therefore is not to be described in more detail. In terms of these joints it is only pointed out that a joint head of the ball joint is connected in a substantially rigid manner to one of the frame parts 14, 15, and that a joint socket, in which the joint head is mounted so as to be rotatable in multiple axes, is connected in a substantially rigid manner to the respective other frame part 14, 15. As a result of at least two such joints 21, 22 which are configured as a ball joint, the degrees of freedom of the joints are restricted to a rotatability about the pivot axis X.

Deviating therefrom, the variant according to FIGS. 2a and 2b does not provide two single joints 21, 22 but provides exclusively a single joint 23 which can be formed by an elongate radial bearing or joint, respectively, or else by a plurality of radial bearings or joints, respectively, that are encapsulated in a module. In comparison to the embodiment of FIGS. 1a and 1b, this results in an improved encapsulation of the joint 23 such that the latter can be more easily installed and is better protected in relation to contamination. However, this in most instances results in a distance for absorbing the forces which is smaller in comparison to the distance which in the variant according to FIGS. 1a and 1b absorbs the forces between the frame parts 14, 15, the distance in the vehicle 1 in FIGS. 2a and 2b corresponding to the length of the single joint 23 along the pivot axis X.

It is also advantageous in the variants according to FIGS. 1a to 2b that a bicycle saddle and the drive device 31 are disposed on the front or first frame part 14 and, as a result, lean into curves when the first frame part 14, having a driver sitting on the vehicle 1, or on the bicycle saddle, respectively, is pivoted or inclined, respectively, such that a driving experience as in a conventional bike is established.

Deviating therefrom, the third variant according to FIGS. 3a and 3b provides that the first frame part 14 and the second frame part 15 are indeed mutually separated, or divided so as to be mutually pivotable, respectively, by two single joints 21, 22, as in the first variant according to FIGS. 1a and 1b, but the drive device 31 and the saddle are not assigned to the front, or first, frame part 14, but to the second, or rear, frame part 15. As a result, the driver when negotiating curves, or generally when the first frame part 14 is being pivoted in relation to the second frame part 15, by way of his/her abdomen does not pivot to the position assumed in the curve, this potentially resulting in an unfamiliar driving experience.

In the vehicle 1 according to FIGS. 3a and 3b, a steeper profile of the pivot axis X moreover results from the positioning of the first joint 21 and the second joint 22. The second joint 22 is presently disposed on a transition between a top tube of the first frame part 14 and a seat tube of the second frame part 15, and the first joint 21 is disposed along the down tube, the latter being divided by the first joint 21 such that one part of the down tube is assigned to the first frame part 14, and a second part of the down tube is assigned to the second frame part 15.

While a ball joint is provided as a first joint 21, and an elastomer element is provided for the second joint 22, in FIGS. 3a and 3b, ball joints or elastomer elements may also be provided for both joints 21.

A steeper profile of the pivot axis X in the variants according to FIGS. 1 and 2 can be achieved, for example, by displacing the joints 21, 22, or the joint 23, respectively, upward along the height axis H, or by displacing the entire superstructure of the second frame part 15 upward along the height axis H, the transport surface and the entire center of gravity of the vehicle 1 being displaced as a result of the latter.

Illustrated in the plan view from above illustrated in FIG. 1b or the respective plan views from above of the variants in FIGS. 1b, 2b and 3b, respectively, apart from the central position, resting position or neutral position of the first frame part 14, these being illustrated using a solid line, are also by way of example deflected or pivoted positions of the first frame part 14 in relation to the second frame part 15, this being illustrated using dashed lines. It becomes obvious here that the contact point A is not or at least not significantly displaced, and the front or first frame part 14 can be tilted or rotated or pivoted, respectively, in the transverse direction Q of the vehicle without the front or first frame part 14 changing the track of the single wheel 14 thereof in relation to the rear or second frame part 15.

In the case of a variation of the vehicle geometry, for example as a result of a pressure loss in the single wheel 11 or a wheel change of the single wheel 11, it can arise that the contact point A of the single wheel 11 is displaced such that the pivot axis X defined by the joints 21, 22, 23 would no longer run through the contact point A, or exactly through the latter, respectively. It is therefore provided that the joints 21, 22, 23 are adjustable, this however not being illustrated in the figures. In the variant according to FIG. 1, a position of the first joint 21 and/or of the second joint 22 is variable in the longitudinal direction L and/or height direction H of the vehicle to this end, such that the profile of the pivot axis X can be adjusted to a new contact point A by way of corresponding variation or displacement of the position. The same also applies to a single joint 23 according to the embodiment of FIGS. 2a and 2b, wherein, as an alternative to an adjustability of the position, an adjustability of the angle may also be provided here such that the angle of the joint 23 in relation to the first frame part 14 and/or the second frame part 15 in the variant according to FIGS. 2a and 2b is varied, and the profile of the pivot axis X can be adjusted as a result.

In order to highlight the difference resulting from the embodiment according to the figures in comparison to the prior art, the single wheel 11 of a vehicle 1 according to certain aspects herein is illustrated in FIG. 4a, and a single wheel 41 of a vehicle known from the prior art is illustrated in FIG. 5a. By tilting the first frame part 14 in relation to the second frame part 15, as is provided in the variants according to FIGS. 1a to 3b, for example, the single wheel 11 or the front wheel, respectively, is inclined about the contact point A such that the latter acts as the fulcrum for the single wheel 11. Accordingly, the single wheel 11, when transitioning to the tilted positions 11′ thereof, is rotated about a fulcrum that lies in the plane of the ground B, this corresponding to the behavior of a normal wheel.

Deviating therefrom, FIG. 4b shows the behavior of a vehicle of the prior art, which likewise has a divided frame, wherein the pivot axis of the front frame part of the latter in relation to the rear frame part of the latter does not run through the contact point A of the single wheel 41 on the ground, but runs parallel to the ground, for example, such that a fulcrum D for the single wheel 41 results when the frame parts are pivoted. When the frame parts are tilted, the single wheel 41 rotates to the tilted positions 41′ thereof, wherein the contact point A as a result is displaced in the transverse direction Q such that this results in deviating contact points A′, or a displacement of the track of the single wheel 41, respectively. The single wheel 41 remains in contact with the ground B by virtue of gravity. If the single wheel were to be fixed about the rotation axis thereof, or about the fulcrum D thereof, respectively, this, when rotating, would result in a height offset H in relation to the ground B.

FIGS. 5a to 5e by way of example show different drive concepts which can be used in the vehicle. The fundamental construction of the vehicle 1, which is illustrated only in portions in FIGS. 5a to 5e, here corresponds to the construction of a vehicle 1 according to the variants of FIGS. 1a to 3b.

Provided in the drive concepts according to FIGS. 5a and 5b as the torque transmission device is a prop shaft which extends from the first frame part 14 into the second frame part 15, wherein the prop shaft runs within the frame parts 14, 15 and, therefore, is not visible. The prop shaft runs so as to be coaxial with the pivot axis X at least in the region of the transition between the first frame part 14 and the second frame part 15.

Provided besides a drive device 31 driven by muscular power in FIG. 5a, or in the vehicle which is shown in portions in FIG. 5a, respectively, is a mid-mounted motor 33 configured as an electric motor as the second drive device, for example, wherein the two drive devices, by way of the prop shaft, transmit a torque generated by the latter from the region of the first frame part 14 to a differential 35 in the region of the second frame part 15, the torque being distributed to the two rear wheels, or to the wheels 12, 13 of the pair of wheels, respectively, by the differential 35.

In the variant according to FIG. 5b, two wheel hub motors 32 are provided instead of a mid-mounted motor 33, wherein each of the wheels 12, 13 of the pair of wheels is assigned one wheel hub motor 32.

Instead of a prop shaft, the embodiments according to FIGS. 5c and 5d provide a chain drive, or a chain gear 34, respectively, as the torque transmission device, wherein the chain of the chain drive 34 is configured to be twisted or torsioned, respectively, within a pre-defined angular range about the pivot axis X, without being damaged.

Instead of a centrally disposed differential 35, the refinement according to FIG. 5c, in each of the wheels 12, 13 of the pair of wheels, provides a freewheeling hub 36, the latter conjointly acting like a differential 35. In this variant, a mid-mounted motor 33 is moreover provided.

Instead of a mid-mounted motor 33, the drive concept according to FIG. 5d provides for each of the wheels 12, 13 of the pair of wheels a wheel hub motor 32 assigned thereto, as well as a chain-driven differential 37.

FIG. 5e illustrates a further drive concept in which a torque from a muscle-power-operated drive device 31 which is presently embodied as a bottom bracket bearing, or as a pedal mechanism, respectively, by means of a chain of a chain gear 34 that is able to be torsioned about the pivot axis X, can be transmitted across the dividing plane of the frame, from the first frame part 14 to a second chain gear 34′ on the second frame part 15. By way of a transverse drive shaft and a second chain, the second chain gear 34′ provides a transmission of torque to the right wheel 12 of the wheels 12, 13 of the pair of wheels in the image plane in which right wheel a wheel hub motor 32 is provided as a “master”. The two wheels 12, 13 of the pair of wheels are not fastened by way of a common axle or shaft, but are in each case fastened separately or individually, respectively, on the luggage frame or on the second frame part 15, respectively. The left wheel 13 in the image plane likewise possesses a wheel hub motor 32, which is however configured as a “slave”. Depending on a torque that is transmitted from the chain drives 34, 34′ to the wheel hub motor 32, configured as the “master”, of the right wheel 12, and/or depending on a control that is adjustable by way of an “accelerator” lever, for example, the wheel hub motor 32, configured as the “slave”, of the left wheel 13 can be actuated, and the left wheel 13 be driven.

The invention is not limited in its embodiment to the preferred exemplary embodiments set out above. Rather, a number of variants are conceivable, which make use of the illustrated solution even with embodiments of fundamentally different types.

Claims

1-10. (canceled)

11. A vehicle comprising: a multi-part frame;a single wheel; anda pair of wheels having two mutually spaced-apart wheels; wherein the single wheel is connected to a first frame part of the frame; and wherein the two wheels of the pair of wheels are mounted on a second frame part of the frame so as to be rotatable about a common axis, whereinthe first frame part and the second frame part are connected by at least one joint, whereinthe first frame part and the second frame part are rotatable relative to one another about a pivot axis defined by the at least one joint, and whereinthe pivot axis runs through a contact point of the single wheel.

12. The vehicle according to claim 11, wherein the single wheel is a front wheel, and whereinthe front wheel is coupled to a wheel fork, the wheel fork being connected to the first frame part so that the front wheel is pivotable about a steering axis.

13. The vehicle according to claim 11, wherein the first frame part and the second frame part are connected by at least two joints which are spaced apart on the pivot axis, whereina first joint of the two joints is at least one of a ball joint, a radial bearing, and an elastomer element and whereina second joint of the two joints is at least one of a ball joint, a radial bearing, and an elastomer element.

14. The vehicle according to claim 13, wherein a position of the first joint and/or of the second joint in relation to the first frame part and/or the second frame part is adjustable.

15. The vehicle according to claim 11, wherein the first frame part and the second frame part are connected by exactly one joint formed by at least one radial bearing.

16. The vehicle according to claim 11, further comprising at least one of the following: a delimiting device which is configured to restrict a rotatability of the first frame part in relation to the second frame part about the pivot axis; anda restoring device which is configured to rotate the first frame part, from a position deflected in relation to a pre-defined central position, back to the central position.

17. The vehicle according to claim 11, further comprising: at least one torque-generating drive device, wherein the at least one torque-generating device is coupled to at least one of the first frame part and the single wheel and is configured to transmit the torque to the single wheel.

18. The vehicle according to claim 11, further comprising: at least one torque-generating drive device that is disposed on the first frame part and, via a torque transmission device, is configured to transmit the torque to at least one of the wheels of the pair of wheels.

19. The vehicle according to claim 18, wherein the torque transmission device is a prop shaft which, at least in a region of a dividing plane between the first frame part and the second frame part that is defined by the at least one joint, extends from the first frame part to the second frame part so as to be coaxial with the pivot axis.

20. The vehicle according to preceding claim 18, wherein the torque transmission device is a chain gear which has a chain and of which the chain permits and compensates a twisting about the pivot axis.

21. The vehicle according to claim 11, further comprising: at least one torque-generating drive device that is disposed on the second frame part and, via a torque transmission device, is configured to transmit a torque to the single wheel.

22. The vehicle according to claim 21, wherein the torque transmission device is a prop shaft which, at least in the region of a dividing plane between the first frame part and the second frame part that is defined by the at least one joint, extends from the first frame part to the second frame part so as to be coaxial with the pivot axis.

23. The vehicle according to claim 21, wherein the torque transmission device is a chain gear which has a chain and of which the chain permits and compensates a twisting about the pivot axis.

24. The vehicle according to claim 11, further comprising: at least one torque-generating drive device, wherein the at least one torque-generating device is coupled to at least disposed on the second frame part or directly on one of the wheels of the pair of wheels and is configured to transmit the torque to at least one of the wheels of the pair of wheels.

25. A vehicle, comprising: a multi-part frame;a first wheel; anda pair of wheels comprising a second wheel and a third wheel, the second wheel and the third wheel being coaxial and spaced apart, wherein the first wheel is connected to a first frame part of the frame, wherein the second wheel and the third wheel are both mounted on a second frame part of the frame, whereinthe first frame part and the second frame part are connected by at least one joint, whereinthe first frame part and the second frame part are rotatable relative to one another about a pivot axis defined by the at least one joint, and whereinthe pivot axis runs through a contact point of the first wheel.

26. The vehicle according to claim 25, wherein the first wheel is a front wheel, and wherein the front wheel is coupled to a wheel fork, the wheel fork being connected to the first frame part so that the front wheel is pivotable about a steering axis.

27. The vehicle according to claim 11, wherein the first frame part and the second frame part re connected by at least two joints which are spaced apart on the pivot axis, wherein a first joint of the two joints is at least one of a ball joint, a radial bearing, and an elastomer element and wherein a second joint of the two joints is at least one of a ball joint, a radial bearing, and an elastomer element.

28. The vehicle according to claim 27, wherein a position of the first joint and/or of the second joint in relation to the first frame part and/or the second frame part is adjustable.

29. The vehicle according to claim 25, wherein the first frame part and the second frame part are connected by exactly one joint formed by at least one radial bearing.

30. The vehicle according to claim 25, further comprising at least one of the following: a delimiting device which is configured to restrict a rotatability of the first frame part in relation to the second frame part about the pivot axis; anda restoring device which is configured to rotate the first frame part, from a position deflected in relation to a pre-defined central position, back to the central position.