Pedal-operated transport vehicle and trailer

Abstract

Pedal-operated transport vehicle (10) comprising: - two steerable front wheels (14), - two rear wheels (16), and - a chassis (12) with two spaced-apart longitudinal members (62) and a central piece (60) arranged therebetween, wherein each of the two longitudinal members (62) is part of a single-track drive module (102) on which a front wheel (14) and a rear wheel (16) are suspended, wherein the rear wheels (16) comprise a first rear wheel (16) with a first electric motor (20) and a second rear wheel (16) with a second electric motor (20), which are coupled to a drive control (48), wherein the rear wheels (16) are mechanically decoupled from each other, and wherein the electric motors (20) can be controlled individually so that the rear wheels (16) can be electrically driven synchronously together.

Description

[0001] The present disclosure relates to a pedal-operated transport vehicle with two front wheels and two rear wheels. Such a vehicle can transport people and / or loads. Such pedal-operated transport vehicles can also be designed as pedal-operated lightweight vehicles or as pedal-operated ultralight vehicles. Finally, the present disclosure relates to a trailer for a pedal-operated transport vehicle and a combination comprising a pedal-operated transport vehicle and a trailer.

[0002] Four-wheeled pedal-assisted light vehicles are known, for example, from DE 20 2019 100 638 U1 and DE 10 2015 120 275 A1. Each of these vehicles has a chassis with a central longitudinal member on which two front wheels and two rear wheels are mounted. The rear wheels are coupled together and can be mechanically driven together.

[0003] DE 197 32 468 A1 discloses a pedal-operated lightweight vehicle with an electromechanical power transmission, whereby no mechanical power transmission takes place between a muscle-powered generator and the vehicle's driven wheels. A similar concept is shown in DE 10 2020 128 385 A1.

[0004] From US 2012 / 0318595 A1 a concept for a modular, pedal-operated light vehicle is known, whereby a frame structure based on tubular profiles is proposed to form a plurality of variants of three-wheelers or four-wheelers.

[0005] For regulatory reasons, certain designs of human-powered vehicles, with and without assisted drive, enjoy advantages with regard to registration requirements, insurance requirements, and / or access permits, as well as parking regulations. This applies, for example, to certain designs of electric bicycles, electric cargo bikes, and the like. In certain jurisdictions, electric bicycles in which an electric auxiliary drive does not exceed a defined continuous power and in which the electric auxiliary drive is not independent of mechanical power generated by human power are considered bicycles. For example, electric auxiliary drives must be deactivated above certain speed limits, and their assistance level must be controlled within the permitted speed range depending on the power generated by human power.This can be done proportionally (linear) or non-proportionally (non-linear).

[0006] This does not necessarily preclude such vehicles from being moved exclusively by electric motor in maneuvering mode. Relevant regulations may vary from country to country. The increased use of alternative vehicles, especially electric-powered vehicles that can be operated without fossil fuels, is being promoted, particularly in urban areas. This could apply to delivery services (so-called "last mile"), but also to passenger transport. Applications are conceivable in both private and commercial settings. Private use can include not only private ownership but also the use of rental or rental services (bike sharing).

[0007] The object underlying the present disclosure is to provide a pedal-operated transport vehicle that is particularly suitable for transporting loads and / or people. The pedal-operated transport vehicle should be usable, for example, as a cargo bike. The pedal-operated transport vehicle should be modular in design to enable a high degree of variant diversity. The pedal-operated transport vehicle should provide a generous loading area. The pedal-operated transport vehicle should be robust and low-maintenance. The pedal-operated transport vehicle should be highly rigid while simultaneously allowing at least a minimum level of ride comfort. The pedal-operated transport vehicle should be easy to move, even with heavy loads, and with comparatively little effort. The pedal-operated transport vehicle should have the most forgiving ride characteristics possible.

[0008] According to a first aspect, the present disclosure relates to a pedal-operated transport vehicle comprising: - two steerable front wheels, - two rear wheels, and - a chassis with two spaced-apart longitudinal members and a central piece arranged between them, wherein each of the two longitudinal members is part of a single-track drive module on which a front wheel and a rear wheel are suspended, wherein the rear wheels comprise a first rear wheel with a first electric motor and a second rear wheel with a second electric motor, which are coupled to a drive control, wherein the rear wheels are mechanically decoupled from each other, and wherein the electric motors can be controlled individually so that the rear wheels can be electrically driven synchronously together.

[0009] In this way, a transport vehicle based on a modular platform can be provided that is suitable for a wide variety of applications. The modular design is based, among other things, on the fact that the central section and the two longitudinal members form separate assemblies of the transport vehicle. The longitudinal members act as supports for essential components of the chassis and the (electric motor) drive.

[0010] The rear wheels are mechanically decoupled from each other, meaning they are not connected by a common (physical) axle. There is no mechanical synchronization or power transmission mechanically coupled to both rear wheels. There is also no mechanical differential.

[0011] Therefore, the central unit does not need to provide a mount, installation space, or anything similar for such an axle (with or without a differential). Instead, at least in exemplary embodiments, there is an "electronic" axle, which is provided by appropriately controlling the two electric motors of the rear wheels. In exemplary embodiments, the rear wheels are driven exclusively by electric motors. This allows the space between the two rear wheels to be freely used, for example, to accommodate cargo or passengers.

[0012] The transport vehicle is designed as a four-wheeler, i.e., a two-track vehicle with two front wheels and two rear wheels. The term "two-track vehicle" does not exclude the possibility of a (small) offset between the front and rear wheels within one axle (right or left side).

[0013] The central section can also be referred to or designed as a central plate, central frame, or central base. The central section is designed to be flat, for example, to provide the greatest possible design freedom with regard to any superstructures. This can include, for example, superstructures for passenger transport, goods transport, and / or combined passenger and goods transport. Superstructures for advertising purposes (visually perceptible displays) are also conceivable.

[0014] The drive modules are each designed, for example, as self-supporting module carriers. The drive modules with a front wheel and a rear wheel can also be referred to as scooters. A drive module comprises, for example, a longitudinal member with a front wheel mounted at the front and a rear wheel mounted at the rear, with the rear wheel having an electric motor or at least being coupled to it. In other words, the electric motor is also contained in the drive module. For example, with regard to the drive of the transport vehicle, the drive modules are coupled exclusively via electrical cables (control and power supply) to other drive components (drive battery, drive controller), which are arranged on the central piece. This does not preclude at least parts of the drive control / motor controller from being arranged on the drive module itself.

[0015] In exemplary embodiments, the electric motors of the rear wheels are designed as hub motors. Hub motors are wheel-integrated motors that are usually directly coupled to the wheels without any intermediate mechanical power transmission (chain drive, belt drive, or similar).

[0016] The transport vehicle can be referred to as a cargo bike, but can also be used for passenger transport. Typically, at least one seat is provided for a driver who pedals the transport vehicle. In particular, this can be a central driver's seat located centrally in the front area of the central section, facing the direction of travel. In other configurations, the transport vehicle has two front seats for two people. Depending on the jurisdiction and intended use, the driver's seat can be located on the right or left. If only one driver's seat is used, an off-center arrangement is also conceivable.

[0017] The transport vehicle can be designated as a cargo bike, and classification as a light / ultralight vehicle is also conceivable. At least in certain jurisdictions, the transport vehicle can be registered as a bicycle / pedelec.

[0018] The platform, which rests on the central section and the drive modules attached to both sides, is suitable for carrying heavy loads. The platform is designed to be flat with an eye on the possible loading space, which improves its capacity for transporting loads. This can include, for example, the ability to accommodate pallets and the like. The concept is robust and easy to maintain. The modular design allows for easy adaptation and variant creation. This can, for example, affect models with different wheelbases and / or different track widths. There is a high degree of flexibility with regard to conceivable superstructures. The handling of the transport vehicle can be favorably influenced by the choice of wheelbase and track width. For example, the central section is variable in terms of length and width. The drive modules, for example, are variable in terms of their length.

[0019] For example, in the case of a fixed wheelbase / axle spacing, the overall width of the transport vehicle can be changed simply by altering the width of the central section. This requires no (or only minimal) adjustments to the drive modules.

[0020] In an exemplary embodiment, the right drive module and the left drive module are designed identically or almost identically, particularly with regard to their longitudinal members. In any case, a high proportion of common parts can be achieved in the drive modules, with positive effects on spare parts inventory, maintenance, and repair.

[0021] In one exemplary embodiment, at least the centerpiece and / or the longitudinal members are largely made of sheet metal parts. The sheet metal parts are, for example, aluminum sheets, which represent a good compromise in terms of weight, load-bearing capacity, and corrosion resistance.

[0022] In one exemplary embodiment, the central section is designed such that the chassis technology (wheels, swing arms, and suspension) is not mounted on the central section, but on the separate longitudinal members. It goes without saying that, at least in exemplary embodiments, the steering is mounted on the central section, for example in the form of a bearing for a steering column / steering rod. The steering can also include a steering gear. A steering gear can also utilize servo assistance, for example in the form of an electric power steering system. So-called steer-by-wire deflections are also conceivable, in which steering commands are detected by sensors and converted into steering movements of the steered wheels exclusively via electromechanical actuators.

[0023] According to another exemplary embodiment, the rear wheels are driven exclusively electrically via their electric motors. This, of course, does not preclude the rear wheels from rotating when the entire transport vehicle is pushed or pulled. The rear wheels are not mechanically coupled to each other for rotational drive.

[0024] According to a further exemplary embodiment, the drive control is designed to operate the electric motors of the rear wheels in different driving modes, comprising at least one synchronized straight-ahead driving mode in which the electric motors drive the rear wheels in the same direction of rotation and at the same rotational speed, and a cornering mode in which the rear wheels are driven at different rotational speeds.

[0025] In this way, for example, favorable handling can be achieved when cornering. The steering behavior of the transport vehicle can be influenced depending on the speed. In other words, an electronic differential can be simulated by controlling the electric motors of the rear wheels in different ways. For example, the handlebars / steering wheel are equipped with sensors to detect steering angles; this can also be used to simulate or control the electric differential. The rear wheels can be driven with distributed torque (so-called torque vectoring).

[0026] In straight-line driving mode, the rear wheels rotate in the same direction and at the same speed. In other modes (cornering mode), the rear wheels rotate in the same direction and at different speeds. Vehicle dynamics control modes are also conceivable in which, in the event of (imminent) wheel slippage, the power supplied by the electric motor is reduced to restore traction.

[0027] A maneuvering mode is also conceivable, in which one wheel is locked and the other is driven to achieve the smallest possible turning circle. Different directions of rotation are also conceivable, if this is desirable for certain driving modes.

[0028] According to another exemplary embodiment, the transport vehicle further comprises a pedal-operated generator associated with a driver's position. The generator is coupled to the drive control system, which controls the electric motors of the rear wheels based on an electrical input power generated by the generator. The driver's position is designed, for example, as a central driver's position, with a driver's seat resting on the central section. The pedal-operated generator is supported, for example, by the central section.

[0029] In a design with two or more seats, it is also conceivable to install two or more pedal-operated generators. Because the pedal-operated generators and the electric motors (or the drive control system) are only electrically connected, two or more such generators can be easily functionally linked. For example, a master-slave configuration is conceivable, in which a first generator is used as an indicator for the selected level of assistance, and at least a second generator is used to provide additional electrical energy, with pedaling converting more mechanical power into electrical power overall. However, an equal configuration is also conceivable.This may, for example, include designs in which two or more pedalable generators are provided, with the selected level of assistance being chosen on the basis of an average generator output.

[0030] According to another exemplary embodiment, the generator is driven by a pedal crank, with power transmission between the pedal crank and the rear wheels occurring electrically. In other words, according to this embodiment, power transmission between the pedals of the transport vehicle and the rear wheels occurs exclusively electrically. There is no mechanical (non-electrical) power transmission between the pedal crank and the rear wheels.

[0031] With an exclusively electric power transmission, mechanical energy is converted into electrical energy when pedaling the generator. The rear wheels are driven exclusively by electrical energy.

[0032] This does not preclude, for example, the generator input from including a transmission, such as a traction drive (chain, belt, etc.). A gear transmission at the generator input is also conceivable. However, the primary concern here is that the generator operates within a favorable speed range at a given cadence.

[0033] According to another exemplary embodiment, the drive control system is configured in an assist mode to drive the rear wheels with a drive power that is higher than the electrical input power currently generated by the generator. In this way, a portion of the drive power is generated by the generator. However, the total power of the drive system is usually the sum of the input power and an additional assist power provided by an energy storage device (usually batteries).

[0034] According to another exemplary embodiment, the drive control is configured in a proportional mode to drive the rear wheels with a drive power that is proportional to the electrical input power generated at the generator. In this way, the more intensively the rider pedals, the greater the electrical assistance. In exemplary embodiments, there is a linear relationship between the input power generated by pedaling and the drive power provided to the electric motors. In exemplary embodiments, there is a non-linear (e.g., progressive or degressive) relationship between the input power generated by pedaling and the drive power provided to the electric motors. Corresponding characteristic curves of various types are conceivable. This includes, for example, different assistance modes.

[0035] According to another exemplary embodiment, the drive control is configured in a maneuvering mode to drive the rear wheels independently of the input power generated by the generator. In this way, the transport vehicle can be moved independently of the input power provided by pedaling the generator. Depending on the jurisdiction and applicable regulations for the classification of the transport vehicle, there are different restrictions for such a mode, in which the transport vehicle can be moved with the pedal crank at a standstill.

[0036] The maneuvering mode, for example, covers speeds up to 6 km / h. When using steer-by-wire steering, remote-controlled operation is also conceivable, and with appropriate sensor technology, even partially autonomous or autonomous operation is possible. This includes, for example, maneuvering with the driver dismounted and using a mobile phone as a control element.

[0037] According to another exemplary embodiment, the drive control is configured in a reverse mode to drive the rear wheels proportionally to the electrical input power generated by the generator for reverse travel. Thanks to the electrical connection between the pedal crank and the rear wheels, reverse travel can be induced by a forward or backward movement of the pedals, depending on the selected control. It is also conceivable, in principle, to initiate reverse travel using a switch or similar device. The operating logic for triggering the reverse mode can also include a combination of simultaneous pedaling and actuating a switch.

[0038] According to another exemplary embodiment, the drive control system is configured in a recuperation mode to convert kinetic energy into electrical energy by operating the electric motors of the rear wheels as generators. This also allows the range of the transport vehicle to be increased. A further advantage of recuperation mode is the reduction of load on the braking system during deceleration, because at least part of the braking energy is used for recuperation.

[0039] According to another exemplary embodiment, the longitudinal members extend in a longitudinal direction, wherein the longitudinal members are designed symmetrically with respect to a vertical center plane oriented parallel to the longitudinal direction. In this way, the longitudinal members, or at least relevant structural parts thereof, can be designed identically or nearly identically. This is advantageous for manufacturing, logistics, and service.

[0040] According to another exemplary embodiment, the longitudinal members and the central piece arranged between them together form a substantially flat floor on their underside. This simplifies the integration of any superstructures. Furthermore, the transport vehicle is thus suitable for transporting bulky loads such as boxes, pallets, and the like.

[0041] In an exemplary embodiment, the central section comprises a central plate with a substantially flat shape. Superstructures include, for example, a driver's compartment and / or a support for the steering / generator. A flat, closed floor further increases the protection of people and cargo on board the transport vehicle from environmental influences.

[0042] It goes without saying that a flat floor can, for example, have ribs / ribs to increase rigidity, as well as ribs / recesses for cable routing, and the like. Openings for the steering and the like in the floor are also conceivable. Nevertheless, passengers and cargo are well protected.

[0043] According to another exemplary embodiment, at least the central member or the longitudinal members comprise a frame structure and at least one floor panel. This can, for example, be a sheet metal part. The floor panel typically serves not only as a covering but also to increase stability.

[0044] According to a further exemplary embodiment, at least the central piece or the longitudinal members comprise a frame structure formed from sheet metal, in particular light metal sheets, which is clad at least in sections. In this way, for example, a sandwich structure with a clad frame can be created, wherein the frame is formed from profile pieces clad by sheet metal. The profile pieces can, in turn, be formed from correspondingly profiled (formed) sheet metal parts.

[0045] According to another exemplary embodiment, the central piece and the longitudinal members have mutually facing longitudinal side surfaces, in particular with a straight extension, at which the central piece and the longitudinal members jointly contact to form the chassis. In other words, the longitudinal members can be flanged to the right and left of the central piece. This increases the space available for the load of the transport vehicle.

[0046] According to another exemplary embodiment, the central piece and the longitudinal members are each coupled via at least two connecting profiles offset from one another in the longitudinal direction, which extend, in particular, in a lateral direction transverse to the longitudinal direction. For example, the connecting profiles are arranged on the underside of the central piece or the longitudinal members to connect them to one another.

[0047] For example, two or more connecting profiles are provided along the longitudinal direction to connect the center piece to at least one of the longitudinal members. It is conceivable to install separate connecting profiles for coupling the right and left longitudinal members. It is also conceivable to use connecting profiles that extend laterally between the two longitudinal members and completely over the center piece.

[0048] In an exemplary design, the mechanical connection between the longitudinal members and the central section is established exclusively via the connecting profiles, so that no connecting elements are required on the facing side surfaces. This also contributes to ensuring that the right and left drive modules, with their respective longitudinal members, are designed as uniformly as possible.

[0049] According to another exemplary embodiment, each of the two single-track drive modules has at least one swing arm for the front wheel or one swing arm for the rear wheel. Thus, the wheels are mounted on the longitudinal members and not on the central section.

[0050] According to a further exemplary embodiment, at least one swing arm has a built-up swing arm body with two swing arms, wherein the swing arm body is constructed in particular from sheet metal, preferably from light metal sheets. In other words, the swing arms can also be assembled from sheet metal parts produced from flat sheet metal sections.

[0051] According to another exemplary embodiment, the swing arm body is constructed from one or more deep-drawn parts. Deep-drawing allows sheet metal to be used to produce comparatively lightweight components with increased strength and rigidity, which are already equipped with functional elements.

[0052] In an exemplary embodiment, tubular constructions, in particular those based on round tubes, are dispensed with for the central piece as well as for the longitudinal members and the rockers.

[0053] According to another exemplary embodiment, the at least one rocker arm is pivotally attached to the longitudinal member via a fabric joint defining a pivot axis, in particular via at least one rubber bushing, the elastomer body of which is firmly connected to the rocker arm on the one hand and to the longitudinal member on the other, allowing relative movement between the rocker arm and the longitudinal member. For example, two rubber bushings offset from one another along the pivot axis are installed.

[0054] The fabric joint does not allow the swing arm to pivot freely relative to the longitudinal member at any angle (e.g., 8°, 10°, 15°, 20°, or 30°). Instead, due to the elastic deformability utilized, only small pivot angles are permitted. This, combined with the restoring forces dependent on the respective pivot angle and other material properties of the elastomer used, results in high load capacity and rigidity, even when fully loaded. Nevertheless, a certain spring and damping effect is still present.

[0055] For example, the rubber bushing is designed as a so-called slotted bushing, with an inner and an outer part, between which at least one elastomer ring is arranged. The inner and outer parts are made of metal materials, with one part being attached to the side member and the other part to the swing arm. The elastomer material can be preloaded in the slotted bushing, resulting in high rigidity.

[0056] According to a further exemplary embodiment, the at least one rocker defines a wheel axle and a pivot axis, wherein the rocker is coupled to the longitudinal member via an elastomer-based spring element which is arranged between the wheel axle and the pivot axis and connects the rocker to the longitudinal member.

[0057] This creates a highly resilient spring element between the swing arm and the longitudinal member, increasing the overall load-bearing capacity of the transport vehicle. The elastomer-based spring element provides a minimum degree of compliance and damping, thus increasing ride comfort. The spring element is designed to optimize installation space, load capacity, and maintenance requirements.

[0058] In one exemplary embodiment, the rocker arms are coupled to the longitudinal member via a fabric joint formed by rubber bushings at the pivot axis, and between the pivot axis and the wheel axle via at least one elastomer-based spring element. Thus, there are no conventional mechanical / fluidic spring / damper elements. This is particularly advantageous for installation space reasons, especially considering the vertical dimensions of conventional spring / damper systems for light vehicles.

[0059] According to another exemplary embodiment, the spring element has a first spring section and a second spring section, each extending between the rocker arm and the longitudinal member, wherein the first spring section and the second spring section are inclined relative to each other and, in particular, oriented in a V-shape. According to this embodiment, the spring element can be designed as a so-called V-bearing. The V-shaped arrangement of the two spring sections ensures high rigidity and load-bearing capacity while providing sufficient comfort.

[0060] The spring element exhibits high rigidity, particularly in the vertical direction. Nevertheless, the elastomer-based spring element allows for a certain degree of deformability in the lateral and, if necessary, longitudinal directions. The design is favorable for assembly and production because the elastomer-based spring element offers a certain degree of tolerance compensation. This avoids over-determination. The effort required for manufacturing and / or correctly adjusting the chassis of the transport vehicle can be reduced.

[0061] According to another exemplary embodiment, the two front wheels each have a steering hub, wherein the two front wheels are pivotable relative to a wheel axle that is stationary with respect to the swing arm about a steering axis that is orthogonal to the wheel axis. In one exemplary embodiment, the two wheel axles of the two front wheels are permanently aligned parallel to each other and coaxial with each other.

[0062] Steering hubs allow steering movements of a wheel with a fixed wheel axle. Fixed wheel axles simplify the design and suspension of wheel carriers (swing arms) for a steerable wheel. A steering hub, for example, has an inner body that cannot be rotated (around the wheel axis) and an outer body that can rotate relative to it about a pivot bearing, which supports the wheel. The steering of the steering hub occurs at the inner body. For this purpose, a fixed link (steering lever), for example, is attached to the body. The outer body also serves, for example, to accommodate a brake disc that rotates with the outer body. In contrast, a support for a brake caliper, for example, is attached to the inner body. The link can be operated via a steering rod, Bowden cables, or similar to pivot the steering hub (outer body and inside the body) around the steering axis.The inner part has a passage for the wheel axle, which allows pivoting movement of the inner part relative to the wheel axle around the steering axis. In other words, the passage is at least partially larger than the cross-section of the wheel axle, thus ensuring the desired degree of freedom between the inner part and the wheel axle.

[0063] In an exemplary embodiment, the two wheel axles of the two front wheels are permanently aligned parallel and coaxial with each other. Accordingly, the two steering hubs can be controlled jointly to execute steering movements of the two front wheels. The two front wheels do not always have to be oriented parallel to each other; depending on the selected steering angle, the wheelbase can be taken into account when cornering.

[0064] According to another exemplary embodiment, the front wheel swing arms are widened between the wheel axle and the side member, with the swing arms being approximately omega-shaped, particularly in a top view. This provides sufficient space to allow for a sufficient steering angle. With a steering system based on steering hubs, the wheel moves relative to the swing arm.

[0065] According to a further exemplary embodiment, a steering lever is attached to each of the facing sides of the steering hubs of the two front wheels, which steering lever extends rearwardly opposite to a direction of travel.

[0066] According to another exemplary embodiment, the two front wheels are coupled to each other via a steering linkage. This allows the movement of the two steering hubs to be functionally coupled. For example, each tie rod is coupled to a steering lever, with the two rods being jointly controlled via a lever located at the lower end of a steering column.

[0067] According to another exemplary embodiment, the steering linkage is controlled via a multi-part steering column having at least one universal joint. This allows the steering column to be conveniently adjusted to the driver's position.

[0068] For example, a three-part steering column with two universal joints is provided, wherein the steering column comprises a steering rod-side section, an intermediate section, and a handlebar-side section, which are coupled to each other by the two universal joints for rotational engagement. The sections can each be inclined relative to each other. This allows for a considerable angular offset between the steering rod-side section and the handlebar-side section.

[0069] According to another exemplary embodiment, the central piece supports a support structure, formed in particular from at least one sheet metal profile, on which the generator is mounted, wherein, in particular, a steering column is also mounted on the support structure. In this way, it is possible to provide a support / holder for the generator (with pedal crank) and the steering column with a (single) structure starting from the central piece (or the central plate).

[0070] According to another exemplary embodiment, the generator is mounted in a generator opening in the support structure, with the support structure being narrower than the generator, at least in a crank area on both sides of the generator. In this way, the width (extension in the lateral direction) of the support structure does not interfere with pedaling the transport vehicle.

[0071] According to another exemplary embodiment, the center piece forms a closed base on both sides of the support structure. This applies in particular to a section of the center piece below the crank area. The closed base protects the rider from splashing water and similar contamination from below. According to another exemplary embodiment, the center piece has two recesses below the crank area that are closed at the bottom. This increases the space available for the crank movement during pedaling (interference circle diameter).

[0072] According to another exemplary embodiment, the generator has an input shaft through which a bottom bracket axle extends. This makes the generator particularly compact, with the pedal crank extending through the generator. In one exemplary embodiment, the generator and its electric motor are designed concentrically to the bottom bracket axle.

[0073] In one exemplary embodiment, the pedal crank is directly coupled to the generator; for example, there is no traction drive (chain, belt, or similar) between the pedal crank and the generator's input shaft. The pedaling frequency and the speed of the generator's input shaft can therefore correspond to one another.

[0074] According to another exemplary embodiment, the transport vehicle further comprises a roof that can be equipped with photovoltaic modules, in particular flexible photovoltaic modules. This allows the vehicle's range to be increased by providing additional electrical energy. Both during idle times and during operation, the power requirement can be at least partially covered by photovoltaics. The roof can be connected to the platform (central section and / or longitudinal beam) via a suitable support structure.

[0075] According to a further exemplary embodiment, the steerable front wheels are steerable via a control element arranged on a steering column, in particular in the form of a steering wheel, wherein a steering ratio is provided between the control element and the front wheels, which converts a rotational movement on the control element into a smaller steering angle of the front wheels. According to this embodiment, a steering system with (rod-shaped) bicycle handlebars is therefore not provided. Instead, a (not necessarily circular) steering wheel is provided. A steering ratio ensures that a pivoting movement generated at the steering wheel is not necessarily converted into a pivoting movement of the same magnitude of the front wheels. A specific steering angle on the steering wheel therefore does not lead to a steering angle of the front wheels with an identical angle.

[0076] According to another exemplary embodiment, the transport vehicle further comprises a parking brake for securing a parking position, wherein the parking brake acts in particular on a brake lever of a mechanical or hydraulic braking system. According to another exemplary embodiment, the parking brake is a mechanical parking brake, for example, a parking brake independent of a hydraulic braking system. This ensures that the four-wheeled transport vehicle does not roll away in an unfavorable orientation (on a slope).

[0077] According to a further exemplary embodiment of the transport vehicle, at least the front wheels or the rear wheels are designed as disc wheels, each having a wheel hub and a rim as well as one or two annular discs connecting them.

[0078] In other words, conventional spokes on spoked wheels can be replaced with ring disks, allowing for a highly rigid and load-bearing wheel design. This increases the load-bearing capacity and robustness of the transport vehicle. Such a constructed disc wheel can therefore comprise a wheel hub and a rim in a generally known manner, with the wheels connected not by a multitude of spokes, but by two ring disks, one on the right and one on the left.

[0079] In an exemplary embodiment, the transport vehicle has an energy display that illustrates the level of power currently generated by the generator, the power currently used by the drive system and, if applicable, the level of power currently generated by the photovoltaic modules.

[0080] According to another exemplary embodiment, two or more batteries are installed, one of which serves primarily to supply the drive and another battery primarily to absorb the energy generated by the photovoltaic modules. For example, the photovoltaic battery can be adapted to the comparatively low but continuous feed-in power, whereas the drive battery is capable of allowing high discharge currents, at least temporarily, to provide high power.

[0081] According to another exemplary embodiment, at least one connection for supplying electrical energy is provided, which is coupled to a battery. The connection can be configured, for example, as a USB port, 12 V port, mains voltage port, or the like.

[0082] According to another exemplary embodiment, the transport vehicle or its drive control can be activated and deactivated via an access control system. This includes, for example, a key-based access control system or a so-called keyless access control system via a smartphone or a token. Access control can also be password-based or PIN-based.

[0083] In one exemplary embodiment, the drive control system has an interface for installing software updates. This can be a wired or wireless interface. A wireless interface may also allow so-called over-the-air updates.

[0084] If the transport vehicle is used as a passenger transport vehicle, it is conceivable to equip at least one or more passenger seats with Isofix mounts for child seats.

[0085] In one exemplary embodiment, the reversing mode includes the output of an acoustic warning signal. In one exemplary embodiment, the transport vehicle has a rearview camera that is activated in reversing mode. A mobile phone can be used as a temporary display to show the video image recorded by the camera. The use of a permanently installed display is also conceivable.

[0086] The transport vehicle is equipped with the vehicle lighting required by regulations, as well as additional lighting functions if required. These include, for example, low beams, high beams, and, if applicable, daytime running lights to increase safety. The use of optical direction indicators (turn signals) is also conceivable. Furthermore, a brake light can be implemented, which is coupled, for example, to an acceleration sensor and activated during significant deceleration.

[0087] The transport vehicle can be equipped with various superstructures. There is also a high degree of design freedom with regard to the design and positioning of the driver's seat, as no mechanical coupling is required to transmit the drive power between the pedal-operated generator and the electric motor drive of the rear wheels. Many different transport vehicles can be realized based on a single platform. This also includes a high degree of flexibility with regard to the height of the superstructure. For example, vehicles with a flat superstructure are conceivable, which utilize an aerodynamic seating position for the driver. However, vehicles with a high superstructure are also conceivable, for example, to maximize cargo space.

[0088] The present disclosure provides a particularly robustly designed pedal-operated transport vehicle that, thanks to its high load-bearing capacity and great flexibility due to its platform design, can be used for a wide variety of applications. Robust, maintenance-friendly components are proposed, particularly for wear-prone and safety-relevant parts, enabling long-lasting, productive operation at moderate maintenance costs.

[0089] According to a further aspect, the present disclosure relates to a trailer for a pedal-operated transport vehicle, in particular for a transport vehicle according to at least one of the embodiments described herein, the trailer comprising: - two wheels, - a chassis with two spaced-apart longitudinal members and a central piece arranged between them, wherein each of the two longitudinal members is part of a single-track drive module on which a wheel is suspended, wherein the wheels comprise a first wheel with a first electric motor and a second wheel with a second electric motor, which can be coupled to a drive control, wherein the wheels are mechanically decoupled from each other, and whereby the electric motors can be driven electrically together synchronously.

[0090] In this way, the transport vehicle can easily be supplemented with a powered trailer, significantly increasing its load capacity. The trailer can be constructed from largely identical or at least similar parts to the transport vehicle.

[0091] In particular, a trailer can also dispense with a continuous mechanical axle between the two wheels. Nevertheless, the wheels can be electrically driven, at least in a supporting manner, via the electric motors. The electric motors can be driven synchronously via the motor control system, resulting in behavior similar to a rigid axle in at least one operating mode. A major advantage of this design, however, is that, due to the electrical coupling between the two wheels (right and left), other operating modes can also be implemented. This includes, for example, assistance when cornering, driving safety modes, and the like.

[0092] Similar to the transport vehicle serving as the towing vehicle, the trailer can be constructed on a modular platform. In exemplary designs, the towing vehicle and the trailer use the same platform.

[0093] A central piece can also be combined with two longitudinal beams on the trailer, resulting in great variability in terms of the width and length of the trailer, for example.

[0094] According to an exemplary trailer design, the wheels are driven exclusively electrically via their electric motors. Similar to the transport vehicle, the absence of a mechanical axle allows for a particularly flat loading area, allowing for the storage of Euro pallets and similar items.

[0095] According to a further exemplary embodiment of the trailer, the electric motors can be controlled at least partially by an external drive control which is installed in a pedal-operated transport vehicle serving as a towing vehicle, wherein a communication interface is installed for communication purposes with the external drive control.

[0096] According to this design, for example, a drive control system of the transport vehicle can communicate with the trailer to transmit appropriate control commands. This does not preclude the possibility of a drive control system also being installed on the trailer. A suitable division of labor is conceivable.

[0097] According to a further exemplary embodiment of the trailer, a drive control is installed in the trailer, which is designed to communicate with an external drive control, in particular in the case of a pedal-operated transport vehicle serving as a towing vehicle, in order to drive the wheels as a function of a generator power generated in the transport vehicle, in particular optionally in a forward driving mode or in a reverse driving mode.

[0098] In this way, the towing vehicle (pedal-driven transport vehicle) can specify a specific operating mode for the trailer. The electric motors of the trailer's wheels can then be driven in an appropriate manner.

[0099] According to a further exemplary embodiment of the trailer, the drive control is designed to operate the wheels in different driving modes, comprising at least one synchronized straight-ahead driving mode in which the electric motors drive the wheels in the same direction of rotation and at the same rotational speed, and a cornering mode in which the wheels are driven at different rotational speeds.

[0100] In particular, this can be used to assist maneuvering with the trailer (forward and reverse) by having the trailer perform or assist appropriate steering movements. It is understood that the trailer's wheels are not necessarily mechanically steerable. Instead, the trailer can initiate and assist any steering movements by using different rotation speeds and / or even different rotation directions of the wheels.

[0101] According to another exemplary embodiment, the trailer further comprises a battery that serves as the traction battery for the trailer. This allows trailers to be carried without unduly adversely affecting the range of the transport vehicle. The capacity of the trailer's battery can be adjusted to the respective load. Identical parts can be installed for both the transport vehicle's battery and the trailer's battery.

[0102] According to another exemplary embodiment of the trailer, each of the two single-track drive modules has at least one swing arm for the wheel. This allows the centerpiece to be designed simply because chassis components (as well as drive components) are at least partially installed in the drive modules.

[0103] According to a further exemplary embodiment of the trailer, the at least one swing arm has a built-in swing arm body with two swing arms, wherein the swing arm body is constructed in particular from sheet metal, preferably from light metal sheets. In this respect, the swing arm is constructed analogously to the swing arm for the rear wheels of the transport vehicle. This can include an identical design. This can also include a similar design using functionally similar or identical components.

[0104] According to another exemplary embodiment of the trailer, the at least one swing arm is pivotally attached to the longitudinal member via a fabric joint defining a pivot axis. In this respect, the swing arm is also constructed analogously to the swing arm for the rear wheels of the transport vehicle. This can involve an identical or at least similar design.

[0105] According to another exemplary embodiment of the trailer, the at least one rocker defines a wheel axle and a pivot axis, wherein the at least one rocker is coupled to the longitudinal member via an elastomer-based spring element arranged between the wheel axle and the pivot axis, connecting the rocker to the longitudinal member. In this respect, the rocker is also constructed analogously to the rocker for the rear wheels of the transport vehicle. This can include an identical or at least similar design.

[0106] According to another exemplary embodiment, each of the two single-track drive modules has two opposing rockers for the wheel, forming a double rocker. This can increase the trailer's suitability for heavy loads. According to this design, a double rocker is installed on the right and left sides of the trailer, each with two opposing rockers (one in front of the wheel axle and one behind the wheel axle). Each of the two rockers of a double rocker can, in turn, be constructed analogously to the rocker for the rear wheels of the transport vehicle. This can involve an identical or at least similar design.

[0107] According to another exemplary embodiment, the trailer further comprises a roof that can be fitted with photovoltaic modules, in particular flexible photovoltaic modules. In this way, the area occupied by the trailer can also be used to generate electrical energy. It goes without saying that the energy generated in this way can be temporarily stored in a battery storage system as needed.

[0108] According to a further exemplary embodiment, the trailer further comprises an active braking system that acts on the wheels, wherein the braking system comprises at least one hydraulic or electric actuator that is coupled to at least one of the wheels for braking intervention, and wherein the braking system is coupled to the transport vehicle electrically for transmitting braking commands. In other words, the braking system for the trailer can be designed according to the brake-by-wire principle. In such a system, the brake pedals / brake levers are not necessarily mechanically / hydraulically coupled to the actuator of the braking system, which ultimately acts mechanically / hydraulically on the wheels of the trailer to decelerate. An advantage of this design is that no hydraulic line connections need to be created between the transport vehicle and the trailer.

[0109] The braking system can be designed as an electro-hydraulic braking system, in which braking signals are transmitted electrically from the transport vehicle to the trailer, with one or more hydraulic actuators on the trailer providing the braking force / braking energy. The braking system can also be designed as an electrical / electromechanical braking system, in which one or more mechatronic actuators are provided to provide the braking force / braking energy.

[0110] According to another exemplary embodiment, the drive control is designed to selectively brake the wheels using electric motors in a generator braking mode through recuperation. This allows deceleration without an additional braking system. The braking effect does not necessarily have to be sufficient to decelerate the trailer to a standstill. Instead, recuperation on the trailer side can at least contribute to the overall braking performance of the combination of transport vehicle and trailer.

[0111] In an exemplary embodiment, both an active braking system (hydraulic or mechatronic brake with electrical control) and braking through recuperation can be used to generate braking power on the trailer. The drive control system can issue corresponding control commands. For vehicle dynamics control purposes, it is conceivable to decelerate the two trailer wheels to different degrees.

[0112] According to a further aspect, the present disclosure relates to a pedalable combination comprising a pedalable transport vehicle according to at least one of the embodiments described herein and a trailer according to at least one of the embodiments described herein

[0113] The trailer can significantly increase the load capacity (both in terms of volume and weight) of the transport vehicle. The trailer is preferably equipped with its own power supply (battery or similar) and its own drive (in the form of electric motors), so that the range of the transport vehicle is not reduced or only slightly reduced.

[0114] It is also conceivable, in principle, to power the trailer's electric motors via the transport vehicle's battery, or vice versa. Active battery management can help align the charge levels of the transport vehicle's and trailer's batteries to optimize the overall range of the combination. It is also conceivable to provide the trailer with excess capacity, allowing electrical energy to be supplied to the transport vehicle without affecting the trailer's own power consumption, thus increasing its range.

[0115] According to an exemplary embodiment of the combination, a communication interface is installed between the transport vehicle and the trailer, along which a communication path extends to control the electric motors of the trailer's wheels. In this way, both the motors of the rear wheels of the transport vehicle and the motors of the trailer's wheels can be controlled in a targeted and coordinated manner. It is generally conceivable to use the drive control of the transport vehicle to control both the electric motors of the transport vehicle and the electric motors of the trailer. However, it is also conceivable to provide a drive control on the trailer itself, which in turn receives control commands from the (higher-level) drive control of the transport vehicle.

[0116] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present disclosure.

[0117] Further features and advantages of the invention will become apparent from the following description and explanation of several exemplary embodiments with reference to the drawings. They show: Fig. 1: a schematic side view of a pedal-operated transport vehicle; Fig. 2: a perspective view of the transport vehicle according to Fig. 1; Fig. 3: a perspective partially exploded view illustrating a platform of the transport vehicle according to Fig. 2; Fig. 4: an exploded perspective view of a central piece forming a central plate of a transport vehicle; Fig. 5: a perspective view of a drive module with a longitudinal member; Fig. 6: an exploded view of the arrangement according to Fig. 5; Fig. 7: an exploded perspective partial view based on the arrangement according to Fig. 6, illustrating a front swing arm; Fig. 8: a schematic view of a spring element; Fig. 9: a partial view of the arrangement according to Fig. 6 to illustrate a rear swing arm; Fig. 10: a perspective partial view of the transport vehicle from below to illustrate a steerable front wheel; Fig. 11: a plan view of the arrangement according to Fig. 10; Fig. 12: a partially sectioned half view of a wheel designed as a disc wheel; Fig. 13: a schematic side view of a combination comprising a pedal-operated transport vehicle and a trailer; Fig. 14: a perspective view of the trailer according to Fig. 13; and Fig. 15: a perspective view of another embodiment of a trailer for a pedal-operated transport vehicle.

[0118] Fig. 1 illustrates, by means of a partially schematic side view, an exemplary design of a transport vehicle designated overall by 10. In addition, reference is made to the perspective views according to Fig. 2 and Fig. 3. The transport vehicle 10 has a chassis 12 on which two front wheels 14 and two rear wheels 16 are mounted. The chassis 12 has a substantially flat floor 18. The floor 18 provides a base for any superstructures. The floor 18 also serves to protect passengers and / or cargo of the transport vehicle 10 from splashing water, soiling from below, and the like. The transport vehicle 10 is designed as a four-wheeler, in particular as a two-track vehicle with two front wheels and two rear wheels. In the view according to Fig. 1, the distance between the front wheels 14 and the rear wheels 16 corresponds to the wheelbase. A distance between the two tracks (compare Fig. 2) corresponds to the track width.

[0119] The rear wheels 16 each have an electric motor 20, which in the exemplary embodiment is designed as a wheel-integrated hub motor. Fig. 2 and Fig. 3 shows that the two rear wheels 16 are not mechanically coupled to each other for rotational drive. Thus, there is no continuous rear axle, no rear axle differential, and the like. An advantage of this design is that the space between the two rear wheels 16 remains free, allowing space for cargo / passengers.

[0120] In the Fig. 1, Fig. 2 and Fig. 3, a (global) direction of travel is indicated by an arrow labeled 24. The direction of travel 24 corresponds to straight-ahead travel when moving forward. It is understood that the transport vehicle 10 is also capable of cornering; for this purpose, the front wheels 14 are steerable. Reverse travel opposite to the direction of travel 24 is also conceivable.

[0121] To control the transport vehicle 10, a driver can be positioned at a driver's position 26, for example, on a driver's seat 28. The driver's seat 28 is supported by the chassis 12. The driver's seat 28 can be a saddle, but can also be a seat with a seat surface and backrest.

[0122] In Fig. 1, a housing 30 is indicated by dashed lines, which protects the occupants and / or cargo of the transport vehicle 10 from environmental influences. The chassis 12 can support a wide variety of superstructures, thus allowing a great deal of design freedom with regard to the housing 30. In the exemplary embodiment according to Fig. 1, the driver's seat 26 and a cargo space 32. The cargo space 32 can be used to accommodate goods / cargo, but also to accommodate passengers who are not the drivers of the transport vehicle 10. The transport vehicle 10 can be used for the transport of goods and for the transport of people.

[0123] In the Fig. 1 and Fig. 2, a roof 34 is indicated, which can be a component of the housing 30. The roof 34 is received and supported on the chassis 12 via supports 36. The roof 34 can be equipped with photovoltaic modules 38 or at least partially formed by photovoltaic modules 38. The modules 38 are, for example, flexible photovoltaic modules that can be attached to a given shape of the roof 34. It is understood that embodiments of the transport vehicle 10 without a roof 34 are also conceivable. A roof 34 and / or a housing 30 are not necessarily required for the structural strength of the transport vehicle 10; this is primarily provided by the chassis 12.

[0124] The transport vehicle 10 can be driven at least partially by muscle power. For this purpose, a generator 40 is provided, which can be driven by a pedal crank 42 to generate electrical energy. The driver in the driver's seat 26 can drive the pedal crank 42 and thus the generator 40 via pedals 44. There is no mechanical connection for power transmission between the pedal crank 42 and the electric motors 20 of the rear wheels 16.

[0125] Instead, power is transmitted electrically, and the electrical energy generated by the generator 40 is used to drive the electric motors 20 of the rear wheels 16. The power that can be generated by the rider is typically amplified by providing additional electrical energy from a battery 46, thus providing assistance when pedaling. The energy flow between the generator 40, the battery 46, and the electric motors 20 of the rear wheels 16 is controlled by a drive controller 48. The drive controller 48 can, for example, determine the level of assistance, i.e., a factor by which the power provided by the rider to drive the electric motor 20 is increased.

[0126] The drive control 48 can individually control the two electric motors 20 of the two rear wheels 16. This allows additional functions to be implemented, such as an electric differential, driving dynamics functions, anti-skid functions, and the like. The electric motors 20 of the rear wheels 16 can also be specifically controlled when cornering, so that the outer rear wheel 16 rotates at a slightly higher speed than the inner rear wheel 16. This allows the handling of the transport vehicle 10 to be optimized when cornering and maneuvering. When traveling straight ahead, the rear wheels are driven as synchronously as possible.

[0127] At least in a maneuvering mode, the drive control 48 is configured to drive the rear wheels 16 independently of the input power provided to the generator 40. For regulatory reasons, the maneuvering mode may be limited to certain operating situations, for example, to very low speeds.

[0128] The drive controller 48 can also drive the rear wheels 16 in a reverse mode. This can occur depending on the input power at the generator 40 or independently. Because there is no mechanical power transmission between the generator 40 and the motors 20 of the rear wheels 16, the direction of rotation of the rear wheels 16 can essentially be opposite to the direction of rotation of the pedal crank 42 on the generator 40. In other words, a reverse mode is conceivable in which the rider drives the pedal crank 42 forward, and the drive controller 48 drives the rear wheels 16 backward on this basis. A reverse mode can essentially also include a co-rotation of the pedal crank 42 and the rear wheels 16.

[0129] The driver can steer the front wheels 14 of the transport vehicle 10 via a control element in the form of a steering wheel 52, which is located at the end of a steering column 54 facing the driver. In the exemplary embodiment, the steering column 54 is designed in three parts, with two universal joints 56 provided along a longitudinal extent of the steering column 54, which couple the three sections of the steering column 54 to one another. In this way, the steering column 54 with the steering wheel 52 can be favorably aligned with respect to the driver.

[0130] With reference to the Fig. 2 and Fig. 3 further illustrates the design of the chassis 12 of the transport vehicle 10. The chassis 12 has a central piece 60 and two longitudinal beams 62, between which the central piece 60 is arranged; compare the assembly illustration according to Fig. 2 and the exploded view in Fig. 3.

[0131] In the exemplary embodiment, the longitudinal members 62 are largely or completely identical in design. The longitudinal members 62 each support a front wheel 14 and a rear wheel 16. The front wheels 14 are mounted on a swing arm 64, which is attached to the longitudinal member 62. The rear wheels 16 are mounted on a swing arm 66, which is attached to the longitudinal member 62. The swing arm 64 is arranged at the front end of the longitudinal members 62, and the swing arm 66 is arranged at the rear end of the longitudinal members 62. The longitudinal members 62 each serve to support the front wheel 14 and the rear wheel 16 of a lane.

[0132] The central piece 60 therefore does not serve to directly accommodate the wheels 14, 16 or their swing arms 64, 66. Instead, the longitudinal members 62 are laterally connected to the central piece 60 to form the chassis 12 as a whole. The central piece 60 carries a support structure 70. The support structure 70 serves to accommodate the steering column 54, see also Fig. 1. The support structure 70 also serves to accommodate the generator 40, which is arranged in a generator opening 72 of the support structure 70. In the exemplary embodiment, the support structure 70 comprises a first support wall 74 and a second support wall 76, see also Fig. 3.

[0133] The generator 40 has an input shaft 80, which in the embodiment coincides with a bottom bracket axle 82 of the pedal crank 42, compare Fig. 2. On both sides of the support structure 70 is a crank area 84, which is subjected to stress by the rotating pedal crank 42 (and the feet of the rider) when pedaling the transport vehicle 10. For ergonomic reasons, the overall width (extension in the lateral direction) of the pedal crank 42 should not be excessively large. Therefore, the support structure 70 with the support walls 74, 76 in the crank area 84 is designed to be no wider than a housing of the generator 40.

[0134] Below the crank area 84 and below the generator 40, the central piece 60 has recesses 86, which are designed, for example, as depressions in the floor 18. The recesses 86 allow the rider's feet to be immersed while pedaling. At the same time, the recesses 86 are closed at the bottom to the ground, thus providing protection against moisture and the like.

[0135] Fig. 3 further illustrates, using a coordinate system 90, 92, 94, directional information used within the scope of the disclosure to describe the design of the transport vehicle 10. An axis designated 90 describes a longitudinal direction parallel to the direction of travel 24. An axis designated 92 denotes a lateral direction transverse to the direction of travel. An axis designated 94 denotes a vertical direction.

[0136] Fig. 3 illustrates, in a partially exploded view, the design of a platform 100 on the basis of which the chassis 12 and ultimately the transport vehicle 10 are formed.

[0137] At least in exemplary embodiments, relevant components of the platform 100 are formed from sheet metal structures. This can, for example, comprise sandwich-like structures with a stiffening frame and cladding panels. However, this does not preclude the cladding panels from also contributing to increased rigidity and load-bearing capacity. In exemplary embodiments, the panels are made entirely or predominantly of aluminum materials. In this way, a favorable ratio of weight, load-bearing capacity, and robustness can be achieved. Suitable joining techniques for connecting components made of aluminum sheets can include clinching, welding, and riveting. Adhesive technologies and screw connections are also conceivable in principle.Panels made of aluminum sheets are generally flat, but can also be provided with beads and similar contours (so-called design lines), for example to increase rigidity and prevent vibrations.

[0138] The platform 100 comprises, in addition to the central piece 60, two drive modules 102, each of which comprises one of the longitudinal members 62 and a front wheel 14 and a rear wheel 16 with an electric motor 20. On their mutually facing sides, the central piece 60 and the longitudinal members 62 each have longitudinal side surfaces 104, 106, which form the interface between the components 60, 62. In the exemplary embodiment, the connection is made via connecting profiles 108, which are arranged below the intermediate piece 60 and the longitudinal members 62; see also the illustration in Fig. 10. In the embodiment according to Fig. 3, three connecting supports 108 are provided on each side of the central piece 60, which are offset from one another in the longitudinal direction 90. It is understood that a larger or smaller number of connecting supports 108 can also be installed. The Fig. 3 and Fig. The connecting profiles 108 shown in Figure 10 are each short profiles that cover only a portion of the central piece 60. It is also conceivable, in principle, to use connecting profiles 108 that extend from a longitudinal member 62 across the lateral extent of the central piece 60 to the opposite longitudinal member 62.

[0139] In this exemplary embodiment, the central piece 60 comprises a central plate 110, into which, in addition to the recesses 86 on both sides of the support structure 70, further recesses 112 are provided. The recesses 112 can be covered by suitable covers. The recesses 112 can accommodate, for example, control technology, cables, batteries, and the like. The recesses 112 are accessible, for example, for maintenance tasks.

[0140] Fig. Figure 4 illustrates an exploded view of an exemplary design of the central plate 110 of the central piece 60. The central plate 110 is formed by a frame structure 118 and a cover plate 120 and floor panel 122 covering the frame. Overall, a sandwich structure results. The frame 118 is flat in the exemplary embodiment and comprises an essentially two-dimensional structure made of sheet metal profiles. The cover plate 120 covers the frame 118 from above. The floor panel 122 covers the frame 118 from below. In the exemplary embodiment, the floor panel 122 forms a closed floor 124, so that passengers and / or cargo of the transport vehicle 10 are well protected against splash water and the like. The closed floor 124 can have passages, for example, for the steering column 54, see Fig. 2.

[0141] In the embodiment according to Fig. 4, the support structure 70 with the two support walls 74, 76 is integrated into the frame structure 118. Fig. 4 further shows the generator opening 72 into which the generator 40 can be inserted, compare the Fig. 1-3. If necessary, for example, the width of the central plate 110 can be changed to alter the track width of the transport vehicle 10. This results in only minor changes to components outside the central plate 100.

[0142] Fig. 5 illustrates, by way of a perspective view, one of the drive modules 102 which are connected laterally to the central piece 60 in order to form the four-wheeled transport vehicle 10. Fig. 6 shows an additional exploded view. In the illustrations in Fig. 5 and Fig. 6, the wheels 14, 16 are hidden for illustrative purposes.

[0143] The longitudinal member 62 extends in the longitudinal direction 90 between the front swing arm 64 and the rear swing arm 66. The front swing arm 64 has two swing arms 130, between which the front wheel 14 can be accommodated. The rear swing arm 66 has two swing arms 132, between which the rear wheel 16 can be accommodated. In the exemplary embodiment, the swing arm 64 has a built-in swing arm body 134, in particular a swing arm body constructed from sheet metal, see also Fig. 7. Likewise, the rocker 66 has a built-up rocker body 136, in particular a rocker body made of sheet metal, see also Fig. 9.

[0144] The rocker arm 64 is mounted on the longitudinal member 62 and pivots about a pivot axis 138. The rocker arm 66 is mounted on the longitudinal member 62 and pivots about a pivot axis 140. The rockers 64, 66 are mounted on the longitudinal member 62 facing away from each other. The two pivot axes 138, 140 are parallel to each other and offset from each other in the longitudinal direction by 90°.

[0145] Fig. 6 shows that the longitudinal member 62 has a frame structure 146 combined with a cover profile 148 and a floor profile 150. The floor profile 150 forms a floor panel 152. The cover profile 148 terminates the frame structure 146 at the top. For example, the overall design of the transport vehicle 10 in the loading space 32 is flat, formed by the cover plate 120 of the central plate 110 and the cover profiles 148 of the longitudinal members 62.

[0146] In the exemplary embodiment, the cover profile 148, together with covers 154, covers the pivot axes 138, 140, in which the rockers 64, 66 are coupled to the longitudinal member 62.

[0147] Fig. Figure 7 illustrates, using an exploded view, the design of the swing arm 64 and its attachment to the longitudinal member 62. In addition to the pivot axis 138, the swing arm 64 also defines a wheel axle 158 of a mounted wheel. The wheel axle 158 is defined, for example, by corresponding openings at the ends of the swing arms 130 facing away from the longitudinal member 62. In the exemplary embodiment, the swing arm body 134 of the swing arm 64 is mounted on the longitudinal member 62 via fabric joints 160.

[0148] The fabric joints 160 are designed, for example, as rubber bushings 162, in particular as so-called slotted bushings. The rubber bushings 162 comprise, for example, an elastomer that sits between a metallic inner part and a metallic outer part. In the exemplary embodiment, the inner part is firmly connected to a holder 164, which is a component of the longitudinal member 62. Furthermore, the outer part is firmly connected to a seat 166 formed on the swing arm body 134. In this way, free rotation of the swing arm body 134 about the pivot axis 138 relative to the longitudinal member 62 is not possible. Instead, the fabric joints 160 only allow limited pivot angles, with the restoring force being greater the larger the pivot angle.

[0149] Between the pivot axis 138 and the wheel axis 158, the rocker arm 64 is further supported on the longitudinal member 62 via a spring element 170. In the exemplary embodiment, the spring element 170 is located between a recess 172 in the rocker arm body 134 and a bearing piece 174, which is held on a support piece 176. The support piece 176 and the bearing piece 174 are part of the longitudinal member 62.

[0150] Fig. Figure 8 illustrates a frontal view of the spring element 170, wherein the view plane is in Fig. 8 perpendicular to the longitudinal direction 90 (compare Fig. 3) is. In Fig. 8, the lateral direction 92 and the vertical direction 94 are also indicated. The spring element 170 is designed, for example, as a so-called V-bearing. The spring element 170 comprises two spring sections 180, 182, which are inclined in a V-shape relative to one another. The spring sections 180, 182 are oriented, for example, symmetrically to a center plane through the spring element 170, which is parallel to the longitudinal direction 90 (perpendicular to the viewing plane in Fig. 8) and the height direction is 94.

[0151] The spring sections 180, 182 each extend between the longitudinal member 62 and the swing arm 64. A load on the longitudinal member 62 acts essentially vertically (arrow 94), so that the inclined spring sections 180, 182 provide a certain degree of deformability, but also a high degree of rigidity. The spring element 170 is also deformable within certain limits in the longitudinal direction 90 and the lateral direction 92, so that a certain degree of tolerance insensitivity is provided. The swing arm body 134 is precisely guided with respect to the pivot axis 138 via two sufficiently spaced-apart fabric joints 160. Overall, using elastomer-based elements, a rigid and precise suspension for the swing arm 64 can be realized in this way, which allows for a certain degree of residual comfort.

[0152] The spring element 170 further forms a head 184 on the side of the rocker arm 64, which, in the event of large deflections, can come into contact with a stop 186 on the side of the longitudinal member 62. In this way, excessive spring movements of the spring element 170 are prevented, for example, in the event of overload.

[0153] The Fig. 7 and Fig. 8 illustrate the suspension of the front swing arm 64 on the longitudinal member 62, whereby this design can also apply to the suspension of the rear swing arm 66 on the longitudinal member 62. Fig. 9 illustrates, in accordance with this, the coupling of the rear swing arm 66 to the longitudinal member 62.

[0154] The swing arm 66 has a counter-holder 190 on one of the swing arms 132, which serves as a torque support for the electric motor 20 of the rear wheel 16, compare also Fig. 1 and Fig. 2. The counterholder 190 can be integrated into the swing arm 132 and manufactured in one piece with it. At the ends of the swing arms 132 facing away from the longitudinal member 62, a wheel axle 198 is defined, which is formed, for example, by downwardly opening receptacles (dropouts) in the swing arms 132.

[0155] The swing arm body 136 is connected to the longitudinal member 62 via at least one fabric joint 200 at the pivot axis 140. The at least one fabric joint 200 allows limited pivot angles about the pivot axis 140. Typically, two fabric joints 200 are provided, offset from one another along the pivot axis 140, for example in the form of two rubber bushings or slotted bushings.

[0156] Between the pivot axis 140 and the wheel axis 198, a spring element 210 is arranged, which is supported on the one hand on the swing arm 66 and on the other hand on the longitudinal member 62, compare also Fig. 8 with the spring element 170 which has the same function. For receiving the spring element 210 in the longitudinal member 62, for example, a bearing piece 214 partially enclosing the spring element 210 is used, which is held by a support piece 216. Similar to the spring element 170 according to Fig. 7, the spring element 210 can also be seated in a recess in the swing arm body 136. To illustrate the further design, reference is again made to Fig. 7.

[0157] Overall, both swing arms 64, 66 can be mounted on the longitudinal member 62 using elastomer-based elements in a rigid, precise, and yet still comfortable manner. The suspension of the swing arms 64, 66 allows a certain amount of spring travel for the front wheels 14 and the rear wheels 16, depending on the load and in response to static / dynamic loads. A damping effect is also provided due to the material properties of the elastomer-based spring elements.

[0158] Fig. 10 illustrates the steering of the transport vehicle 10 using a partial view of the transport vehicle 10 in the area of the left front wheel 14 (from the driver's perspective). Fig. Figure 10 shows a section of the central piece 60, the longitudinal member 62 and the (front) rocker arm 64 from below. This also illustrates the (essentially flat) floor 124 and an exemplary design of a connecting profile 108. Reference is also made to the top view according to Fig. 11, which shows a similar section of the transport vehicle 10 from above.

[0159] The front wheels 14 each comprise a steering hub 220 to which a steering lever 222 is attached. The steering lever 222 is coupled to a lever 226 via a steering linkage 224, wherein the lever 226 is actuated by the steering column 54. In other words, the steering column 54 can extend through the central piece 60 on the underside of the floor 124. A steering movement of the steering wheel 52 (see Fig. 2) produces a corresponding pivoting movement of the lever 226, resulting in a deflection of the steering lever 222, which is transmitted through the steering linkage 224. Instead of the Fig. 10, a steering gear can also be installed which drives the steering linkage 224.

[0160] In plan view according to Fig. 11, the steering linkage 224 is not shown, but the steering lever 222 on the steering hub 220 is. The front wheel 14 is in Fig. 11 in a straight-ahead driving position (neutral position, solid lines) and a curve position (dashed lines). In the curve position, a hub axle 226 of the steering hub 220 is pivoted relative to the wheel axle 158 about a steering axis 228. In the neutral position, the hub axle of the steering hub 220 coincides with the wheel axle 158. The steering axis 228 is in the view orientation according to Fig. 11 is oriented approximately orthogonally to the viewing plane. It is understood that starting from the neutral position, deflections in both directions are possible, i.e., to the right or to the left from the driver's perspective.

[0161] As already explained above, the steering hub 220 of the front wheels 14 is designed, for example, in two parts with an inner body and an outer body, wherein the inner body is not rotatable about the wheel axle 158. However, the outer body is rotatable about the inner body and about the wheel axle 158. The inner body is pivotable about the steering axis 228 relative to the fixed wheel axle 158 to enable steering movements. The wheel axle 158 is fixedly mounted on the swing arm body 134 of the swing arm 64. The wheel axle 158 and the swing arm 64 themselves are not pivotable relative to the steering axis 228.

[0162] Fig. 11 further shows that the swing arm body 134 of the front swing arm 64 is approximately omega-shaped. In other words, the swing arm body 134 is widened between the wheel axle 158 and the connection to the longitudinal member 62 in order to provide sufficient clearance for the deflection of the front wheels 14. The two swing arms 130 of the swing arm 64 are each curved outwardly (away from the front wheel 14) along their longitudinal extent. With a purely U-shaped design of the swing arm body 134, the two swing arms 130 would have a largely straight longitudinal extent. In the design according to Fig. 11, there is therefore an area in the longitudinal direction 90 between the longitudinal member 62 and the wheel axle 158 in which the distance between the two swing arms 130 is greater than the distance between the two swing arms 130 from each other in the area of the wheel axle 158.

[0163] With reference to Fig. 12 shows a partially sectioned half view of an exemplary design of a disc wheel 250. Both the front wheels 14 and the rear wheels 16 (compare the Fig. 1-3) can generally be designed as disc wheels 250. The disc wheel 250 has a wheel hub 252 and a rim 254 in which the tire 256 is located. The wheel hub 252 can be used as a steering hub 220 (see Fig. 10 and Fig. 11). Also designated by 260 is a hub axle of the wheel hub 252. Typically, a plurality or multiplicity of spokes extend between the wheel hub 252 and the rim 254. In the embodiment according to Fig. 11, no spokes are provided, but instead two annular discs 262, which extend between the wheel hub 252 and the rim 254. Overall, a roughly disc-shaped design results. Each of the two annular discs 262 has a Fig. 12, which is rotated around the hub axis 260. The annular discs 262 can be designed symmetrically to one another, resulting in an identical or nearly identical design. However, it is also conceivable to provide the two annular discs 262 with different cross-sectional profiles.

[0164] Fig. Figure 13 illustrates a side view of a combination designated 300, which is formed from a transport vehicle 10 and a trailer 310. The design of the transport vehicle 10 has already been described in connection with the Fig. 1-12 are comprehensively illustrated, so reference is made to them to avoid repetition.

[0165] The trailer 310 and the transport vehicle 10 can utilize a large number of identical parts. The trailer 310 can be constructed in a similar manner to the transport vehicle 10, based on a modular system. In particular, the trailer 310, like the transport vehicle 10, can be designed to be variable in terms of width, length, and also in terms of any superstructure.

[0166] Due to the common parts concept and modularity, the following primarily focuses on the special properties of the trailer 310. Furthermore, reference is made to the comprehensive above detailed description of the transport vehicle 10 and its components, from which the design of relevant components of the trailer 310 also results.

[0167] The trailer 310 has a chassis 312, which in the exemplary embodiment comprises two wheels 314, compare also the perspective view according to Fig. 14. In the illustrated example, trailer 310 is designed as a single-axle trailer. Designs with two axles are also conceivable.

[0168] The trailer 310 has a chassis 312, which forms a substantially flat floor 318, particularly between the wheels 314. The floor 318 is designed, for example, to accommodate at least one pallet (a Euro pallet with a length of 120 cm and a width of 80 cm). This does not preclude the possibility that, in certain embodiments, two Euro pallets (corresponding to a length of 160 cm and a width of 120 cm) can even be transported side by side or one behind the other.

[0169] The wheels 314 are driven in a manner already described above by electric motors 320, which in the exemplary embodiment are designed as wheel hub motors. There is no mechanical connection between the wheels 314 in the form of a common rigid axle or the like.

[0170] The design of the wheels 314 or the electric axle formed by them corresponds completely or largely to the design of the rear axle with the rear wheels 16 of the transport vehicle 10.

[0171] In the embodiment according to Fig. 13, the trailer 310 has a drawbar 324 with a coupling counterpart 326 which is adapted to a coupling 328 mounted on the transport vehicle 10. Fig. 14 shows the drawbar 324 in perspective view. The coupling 328 and the coupling counterpart 326 together form a trailer coupling, which, for example, comprises a ball joint and provides corresponding degrees of rotational freedom between the transport vehicle 10 and the trailer 310. For forward travel (compare arrow 24 in Fig. 13) and reverse travel in the opposite direction, power can be transmitted via the trailer coupling between the transport vehicle 10 and the trailer 310.

[0172] In the Fig. 13 and Fig. In Figure 14, 332 indicates a possible loading space of trailer 310. The loading space 332 can be used flexibly, including for possible superstructures. The trailer 310 is generally suitable for transporting cargo. Depending on the application, passenger transport is also possible.

[0173] Analogous to the transport vehicle 10, the trailer 310 can also be provided with a housing or a roof 334 equipped with photovoltaic modules 338, compare the Fig. 1 and Fig. 2. For a description of a corresponding embodiment, reference is made to the embodiment shown there.

[0174] The trailer 310 is not a completely passive trailer that is moved exclusively by a towing vehicle. In the exemplary embodiment according to the Fig. 13 and Fig. 14, the trailer 310 is provided with at least one auxiliary drive by the electric motors 320. For example, the electric motors 320 are adapted to the expected loads of the trailer 310, so that, from the perspective of the transport vehicle 10, no additional load is imposed during travel. In other words, designs are conceivable in which (from the perspective of the transport vehicle 10) the electric motors 320 drive the wheels 314 of the trailer 310 with the aim of compensating for the weight of the trailer 310 during the movement of the transport vehicle 10.

[0175] The trailer 310 can generally be equipped with a power supply in the form of a traction battery or battery 346. The battery 346 serves to power the electric motors 320 for driving the wheels 314.

[0176] In exemplary embodiments, the trailer 310 has a drive control 348. The drive control serves to control the electric motors 320 of the wheels 314. In this way, for example, an electric axle can be provided in which both wheels 314 are driven synchronously, comparable to a rigid axle. However, other operating modes are also conceivable in which the two wheels 314 of the trailer 310 are deliberately driven at different rotational speeds or even in different directions of rotation. In this way, assistance can be provided when maneuvering, cornering, reversing, starting off, or in extreme driving situations (one-sided slip, risk of skidding, or the like). It is fundamentally conceivable for the drive control 348 to operate autonomously and independently transmit corresponding control commands to the electric motors 320.

[0177] However, it is also conceivable to couple the trailer 310 to the drive control 48 of the transport vehicle 10 for control purposes via a communication path 350 extending along an interface 352. In this way, the previously described functionality of the drive control 48 of the transport vehicle 10 can be used to transmit suitable control commands to the trailer 310 or to its electric motors 320. This can be done directly or via the drive control 348 of the trailer 310. In particular, a currently defined level of assistance can be transmitted (directly or indirectly) to the electric motors 320 of the wheels 314 via the drive control 48 (of the transport vehicle 10).

[0178] The interface 352 or the communication path 350 can be provided by suitable connectors and cable connections. At least partially wireless communication is not excluded.

[0179] In principle, it is also conceivable that the battery 346 of the trailer 310 can be coupled directly or indirectly to the battery 46 of the transport vehicle 10. In a coupled state, the charge levels of the batteries 46, 346 can be adjusted to each other using battery management. Furthermore, in certain operating modes, energy can be transferred from the trailer 310 to the drive of the transport vehicle 10, or vice versa.

[0180] In Fig. 13, a braking system 354 is further indicated, which acts on both wheels 314. The braking system 354 is designed, for example, as an electro-hydraulic braking system with electrical control (brake-by-wire). In the exemplary embodiment, the braking system 354 comprises an actuator 356, which is hydraulically coupled to a brake shoe or a brake piston on one wheel 314 or both wheels 314. However, there is no hydraulic connection between the transport vehicle 10 and the trailer 310. Instead, the actuator 356 is controlled via an electrical line 358. This simplifies the coupling and uncoupling of the trailer 310. Nevertheless, the trailer 310 can be actively decelerated by the braking system 354. An electromechanical braking system with one or two mechatronic actuators is also conceivable, dispensing with any hydraulics in the trailer 310.

[0181] In principle, the use of recuperation in the electric motors 320 to generate deceleration is also conceivable. The drive control 348 can control the electric motors 320 in a suitable manner. By specifically controlling the two electric motors 320 of the wheels 314, a different deceleration can be achieved for the right and left wheels 314, for example, for reasons of vehicle dynamics control.

[0182] Fig. 14 illustrates the already mentioned Fig. 13 trailer 310 shown in side view in a perspective view.

[0183] Similar to the chassis 12 of the transport vehicle 10, the chassis 312 ( Fig. 13) of the trailer 310 is formed by a central piece 360 and two laterally adjacent longitudinal members 362. In this way, by varying the central piece 360, the width and, if necessary, also the length of the trailer 310 or its loading space 332 can be easily changed. This has no or only limited effects on the design of the longitudinal members 362.

[0184] The wheels 314 are in the embodiment according to Fig. 14 held by swings 366. A special feature is the Fig. The design of the trailer 310 shown in Figure 14 has a double rocker formed by two mutually facing rockers 366. This results in high rigidity, allowing it to support heavy loads.

[0185] For the detailed design of the central piece 360 and for conceivable detailed designs of the longitudinal members 362, reference is made to the previously illustrated designs of the central piece 60 and the longitudinal members 62 of the transport vehicle 10, in particular to avoid repetition.

[0186] The swing arm 366 for the wheels 314 is basically similar to the one already described Fig. 9 and other figures, the swing arm 66 for the rear wheels 16 of the transport vehicle is designed so that reference is made to it to avoid repetition. Due to the common parts concept, similar or identical swing arms can also be used on the trailer 310.

[0187] The rockers 366 each have a rocker body 436, for the conceivable detailed design of which, in order to avoid repetition, reference is made to the design of the rocker body 136 of the rocker 66, compare in particular to Fig. 6 and Fig. 9. Due to the common parts concept, similar or identical swing arm bodies can also be used on the 310 trailer.

[0188] The Fig. Fourteen mutually facing rockers 366 each have a rocker body 436. The rocker bodies 436 face each other and jointly support the wheel 314 arranged therebetween, which has the electric motor 320.

[0189] In addition, reference is made to Fig. 15, which illustrates another exemplary embodiment of a trailer designated overall by 510. The design of trailer 510 is largely similar to that of trailer 310. One difference is that trailer 510 dispenses with the double-swing design, and instead, the wheels 314 are mounted on a (single) swing arm 366, similar to the rear wheels 14 of the transport vehicle 10.

[0190] The detailed design of the Fig. 14 and Fig. 15 can be derived from the descriptions of the swing arm 66 of the transport vehicle 10. In particular, Fig. 9 in conjunction with Fig. 7 shows the coupling of the rocker arm 66 via a fabric joint 200 to the longitudinal member 62. Similar or identical principles are also conceivable for the coupling between the rocker arms 366 and the longitudinal members 362. Due to the modularity, the design principles shown and, if necessary, even components and assemblies can also be used for the trailers 310, 510.

[0191] Furthermore, Fig. 9 in conjunction with the Fig. 7 and Fig. 8 shows a spring-loaded suspension of the rocker arm 66 via a spring element 170 on the longitudinal member 62. Similar or identical principles are also conceivable for the spring-loaded mounting of the rocker arms 366 on the longitudinal members 362. Due to the modularity, the design principles shown and, if necessary, even components and assemblies can also be used on the trailers 310, 510.

[0192] The platform concept previously explained in connection with the transport vehicle 10 is also continued in the trailers 310, 510. In Fig. 14, the platform (in the sense of a modular construction kit) is indicated by 400. In addition to the central piece 360, the platform 400 comprises two drive modules 402, which are coupled laterally to the central piece 360. An advantage of the electrical coupling between the two wheels 314 is the elimination of mechanical axles or similar mechanical power transmission elements extending between the two wheels 314. This results in a particularly simple and flat design of the platform 400, from which the usable loading space 332 benefits. In particular, the loading space 332 represents a flat, continuous floor 318 ( Fig. 13) ready.

[0193] In exemplary embodiments, the trailer 310, 510 has a braking system, but this is not intended to be limiting. Similar to the transport vehicle 10, the trailer 310, 510 can in principle be capable of recuperation. In this way, a certain amount of braking power can be provided.

[0194] It is understood that the design of the trailers 310, 510 may at least partially utilize the previously described design of the transport vehicle 10 and its components. Corresponding designs and combinations are expressly encompassed by the present disclosure. In connection with the Fig.The detailed designs of the transport vehicle 10 described in Figures 1-12 can also be readily transferred to relevant assemblies and components of the trailers 310, 510. In particular, the manufacturing concept and a high number of possible identical parts allow for efficient production of the trailers 310, 510, in addition to the transport vehicle 10. The identical parts concept allows the adoption of relevant designs and construction principles at the component and assembly level. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 20 2019 100 638 U1

[0002] DE 10 2015 120 275 A1

[0002] DE 197 32 468 A1

[0003] DE 10 2020 128 385 A1

[0003] US 2012 / 0318595 A1

[0004]

Claims

[1] Pedal-operated transport vehicle (10) comprising: - two steerable front wheels (14), - two rear wheels (16), and - a chassis (12) with two spaced-apart longitudinal members (62) and a central piece (60) arranged therebetween, wherein each of the two longitudinal members (62) is part of a single-track drive module (102) on which a front wheel (14) and a rear wheel (16) are suspended, wherein the rear wheels (16) comprise a first rear wheel (16) with a first electric motor (20) and a second rear wheel (16) with a second electric motor (20), which are coupled to a drive control (48), wherein the rear wheels (16) are mechanically decoupled from each other, and wherein the electric motors (20) can be controlled individually so that the rear wheels (16) can be electrically driven synchronously together. [2] Transport vehicle (10) according to claim 1, wherein the rear wheels (16) are driven exclusively electrically via their electric motors (20). [3] Transport vehicle (10) according to claim 1 or 2, wherein the drive control (48) is designed to operate the electric motors (20) of the rear wheels (16) in different driving modes, comprising at least one synchronized straight-ahead driving mode in which the electric motors (20) drive the rear wheels (16) in the same direction of rotation and at the same rotational speed, and a cornering mode in which the rear wheels (16) are driven at different rotational speeds. [4] Transport vehicle (10) according to one of claims 1-3, further comprising a pedalable generator (40) associated with a driver's position (26), the generator (40) being coupled to the drive control (48) which controls the electric motors (20) of the rear wheels (16) on the basis of an electrical input power generated at the generator (40). [5] Transport vehicle (10) according to claim 4, wherein the generator (40) is drivable via a pedal crank (42), and wherein power transmission between the pedal crank (42) and the rear wheels (16) is effected electrically. [6] Transport vehicle (10) according to claim 4 or 5, wherein the drive control (48) is designed in an assistance mode to control the rear wheels (16) with a drive power that is higher than an electrical input power currently generated at the generator (40). [7] Transport vehicle (10) according to one of claims 4-6, wherein the drive control (48) is designed in a shunting mode to drive the rear wheels (16) independently of an input power generated at the generator (40). [8] Transport vehicle (10) according to one of claims 4-7, wherein the drive control (48) in a reverse mode is designed to drive the rear wheels (16) proportionally to the electrical input power generated at the generator (40) for reverse travel. [9] Transport vehicle (10) according to one of claims 1-8, wherein the longitudinal members (62) extend in a longitudinal direction (90) and are designed symmetrically with respect to a vertical center plane oriented parallel to the longitudinal direction (90). [10] Transport vehicle (10) according to one of claims 1-9, wherein the longitudinal members (62) and the central piece (60) arranged therebetween together form a substantially flat floor (18) on their underside. [11] Transport vehicle (10) according to one of claims 1-10, wherein at least the central piece (60) or the longitudinal members (62) have a frame structure (118, 146) and at least one floor panel (122, 152). [12] Transport vehicle (10) according to one of claims 1-11, wherein at least the central piece (60) or the longitudinal members (62) have a frame structure (118, 146) formed from sheet metal, in particular light metal sheets, which is at least partially covered. [13] Transport vehicle (10) according to one of claims 1-12, wherein the central piece (60) and the longitudinal members (62) have mutually facing longitudinal side surfaces (104, 106), in particular with a rectilinear extension, at which the central piece (60) and the longitudinal members (62) jointly contact to form the chassis (12). [14] Transport vehicle (10) according to one of claims 1-13, wherein the central piece (60) and the longitudinal members (62) are each coupled via at least two connecting profiles (108) offset from one another in the longitudinal direction (90), which extend in particular in a lateral direction (92) transverse to the longitudinal direction (90). [15] Transport vehicle (10) according to one of claims 1-14, wherein each of the two single-track drive modules (102) has at least one swing arm (64) for the front wheel (14) or one swing arm (66) for the rear wheel (16). [16] Transport vehicle (10) according to claim 15, wherein the at least one rocker (64, 66) has a built-up rocker body (134, 136) with two rocker arms (130; 132), wherein the rocker body (134, 136) is constructed in particular from sheet metal, preferably from light metal sheets. [17] Transport vehicle (10) according to claim 15 or 16, wherein the at least one rocker arm (64, 66) is pivotally attached to the longitudinal member (62) via a fabric joint (160, 200) defining a pivot axis (138, 140), in particular via at least one rubber bushing (162), the elastomer body of which is firmly connected on the one hand to the rocker arm (64, 66) and on the other hand to the longitudinal member (62) and allows a relative movement between the rocker arm (64, 66) and the longitudinal member (62). [18] Transport vehicle (10) according to one of claims 15-17, wherein the at least one rocker (64, 66) defines a wheel axle (158, 198) and a pivot axis (138, 140) and is coupled to the longitudinal member (62) via an elastomer-based spring element (170, 210) which is arranged between the wheel axle (158, 198) and the pivot axis (138, 140) and connects the rocker (64, 66) to the longitudinal member (62). [19] Transport vehicle (10) according to claim 18, wherein the spring element (170, 210) has a first spring portion (180) and a second spring portion (182), each extending between the rocker (64, 66) and the longitudinal member (62), wherein the first spring portion (180) and the second spring portion (182) are inclined to one another and are oriented in a V-shape. [20] Transport vehicle (10) according to one of claims 1-19, wherein the two front wheels (14) each have a steering hub (220) and are pivotable relative to a wheel axle (158) fixed with respect to the rocker arm (64) about a steering axis (228) which is orthogonal to the wheel axle (158). [21] Transport vehicle (10) according to claim 20, wherein the rockers (64) of the front wheels (14) are widened between the wheel axle (158) and the longitudinal member (62), and wherein the rockers (64) are designed approximately omega-shaped, in particular in a plan view. [22] Transport vehicle (10) according to claim 20 or 21, wherein a steering lever (222) is fastened to each of the mutually facing sides of the steering hubs (220) of the two front wheels (14), which steering lever extends rearwardly opposite to a direction of travel (24). [23] Transport vehicle (10) according to one of claims 1-22, wherein the two front wheels (14) are coupled to each other via a steering linkage (224). [24] Transport vehicle (10) according to claim 23, wherein the steering linkage (224) is controlled via a multi-part steering column (54) having at least one universal joint (56). [25] Transport vehicle according to one of claims 1-24, wherein the central piece (60) carries a support structure (70) formed in particular from at least one sheet metal profile, on which the generator (40) is mounted, and in particular wherein a steering column (54) is further mounted on the support structure (70). [26] Transport vehicle according to claim 25, wherein the generator (40) is mounted in a generator opening (72) in the support structure (70), and wherein the support structure (70) is designed to be narrower than the generator (40) at least in a crank region (84) on both sides of the generator (40). [27] Transport vehicle according to claim 25 or 26, wherein the central piece (60) forms a closed floor (124) on both sides of the support structure (70). [28] Transport vehicle according to one of claims 1-27, wherein the generator (40) has an input shaft (80) through which a bottom bracket axle (82) extends. [29] Transport vehicle according to one of claims 1-28, further comprising a roof (34) which can be equipped with photovoltaic modules (38), in particular with flexible photovoltaic modules. [30] Transport vehicle according to one of claims 1-29, wherein the steerable front wheels (14) are steerable via a control element (52) arranged on a steering column (54), in particular in the form of a steering wheel, and wherein a steering ratio is provided between the control element (52) and the front wheels (14), which translates a rotational movement on the control element (52) into a smaller steering angle of the front wheels (14). [31] Transport vehicle according to one of claims 1-30, further comprising a parking brake for securing a parking position, wherein the parking brake acts in particular on a brake lever of a mechanical or hydraulic braking system. [32] Transport vehicle according to one of claims 1-31, wherein at least the front wheels (14) or the rear wheels (16) are designed as disc wheels (250), each having a wheel hub (252) and a rim (254) as well as one or two annular discs (262) connecting them. [33] Trailer (310, 510) for a pedal-operated transport vehicle according to any one of claims 1-32, comprising: - two wheels (314), - a chassis (312) with two spaced-apart longitudinal beams (362) and a central piece (360) arranged therebetween, wherein each of the two longitudinal members (362) is part of a single-track drive module (402) on which a wheel (314) is suspended, wherein the wheels (314) comprise a first wheel (314) with a first electric motor (320) and a second wheel (314) with a second electric motor (320), which can be coupled to a drive control (48, 348), wherein the wheels (314) are mechanically decoupled from each other, and wherein the electric motors (320) can be electrically driven synchronously together. [34] Trailer (310, 510) according to claim 33, wherein the wheels (314) are driven exclusively electrically via their electric motors (320). [35] Trailer (310, 510) according to claim 33 or 34, wherein the electric motors (320) are at least partially controllable by an external drive control (48) which is installed in a pedal-operated transport vehicle (10) serving as a towing vehicle, and wherein a communication interface (352) is installed for communication purposes with the external drive control (48). [36] Trailer (310, 510) according to one of claims 33-35, wherein a drive control (348) is installed in the trailer (310, 510), which is designed to communicate with an external drive control (48), in particular in the case of a pedal-operated transport vehicle (10) serving as a towing vehicle, in order to drive the wheels (14) as a function of a generator power generated in the transport vehicle (10), in particular optionally in a forward driving mode or in a reverse driving mode. [37] Trailer (310, 510) according to one of claims 33-36, wherein the drive control (48, 348) is designed to operate the wheels (314) in different driving modes, comprising at least one synchronized straight-ahead driving mode in which the electric motors (320) drive the wheels (314) in the same direction of rotation and at the same rotational speed, and a cornering driving mode in which the wheels (314) are driven at different rotational speeds. [38] Trailer (310, 510) according to any one of claims 33-37, further comprising a battery (446) serving as a drive battery for the trailer (310, 510). [39] Trailer (310, 510) according to one of claims 33-38, wherein each of the two single-track drive modules (402) has at least one swing arm (366) for the wheel (314). [40] Trailer (310, 510) according to claim 39, wherein the at least one swing arm (366) has a built-up swing arm body (436) with two swing arm arms, wherein the swing arm body (436) is constructed in particular from sheet metal, preferably from light metal sheets. [41] Trailer (310, 510) according to claim 39 or 40, wherein the at least one rocker (366) is pivotally attached to the longitudinal member (362) via a fabric joint defining a pivot axis. [42] Trailer (310, 510) according to any one of claims 39-41, wherein the at least one rocker (366) defines a wheel axle and a pivot axis and is coupled to the longitudinal member (362) via an elastomer-based spring element arranged between the wheel axle and the pivot axis and connecting the rocker (366) to the longitudinal member (362). [43] Trailer (310, 510) according to one of claims 39-42, wherein each of the two single-track drive modules (402) has two opposing rockers (366) for the wheel (314) forming a double rocker. [44] Trailer (310, 510) according to one of claims 39-43, further comprising a roof (334) which can be equipped with photovoltaic modules (338), in particular with flexible photovoltaic modules. [45] Trailer (310, 510) according to one of claims 39-44, further comprising an active braking system (354) acting on the wheels (314), wherein the braking system (354) comprises at least one hydraulic or electric actuator (356) coupled to at least one of the wheels (314) for braking intervention, and wherein a coupling of the braking system (354) to the transport vehicle (10) for transmitting braking commands is effected electrically. [46] Trailer (310, 510) according to one of claims 39-45, wherein the drive control (48, 348) is designed to specifically brake the wheels (314) by electric motors (320) in a generator braking mode by means of recuperation. [47] Pedalable combination (300) with a pedalable transport vehicle (10) according to one of claims 1-32 and a trailer (310, 510) according to one of claims 33-46. [48] Trailer (300) according to claim 47, wherein a communication interface (352) is installed between the transport vehicle (10) and the trailer (310, 510), along which a communication path (350) extends for controlling the electric motors (320) of the wheels (314) of the trailer (310, 510).

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