DRIVE ARRANGEMENT WITH ECCENTRIC GEARBOX FOR A MUSCLE-POWERED VEHICLE AND VEHICLE WITH THE DRIVE ARRANGEMENT

Description

[0001] The invention relates to a drive arrangement for a muscle-powered vehicle with the features of the preamble of claim 1. Furthermore, the invention relates to a vehicle with the drive arrangement.

[0002] Electric bicycles exist that can be propelled without a physical drive connection between the pedal crank and the rear wheel. The rider uses the pedal cranks to drive a generator, which in turn powers a drive motor connected to the rear wheel. With such a drive system, the physical drive connection, such as a chain, toothed belt, driveshaft, etc., is eliminated. To increase the crankshaft speed and correspondingly reduce the torque, conventional gear types, such as single- or multi-stage planetary gears, Wolfrom sets, etc., are typically used to enable the use of a generator with low torque and a correspondingly small size.

[0003] German patent application DE 59709997 D1 discloses a vehicle, in particular a bicycle, that can be propelled by muscle power. The bicycle has a generator that can be driven by a vehicle user to generate electricity, and at least one electric motor for propelling the vehicle, which is connected to the generator to transmit electrical power. In particular, a transmission for increasing the rotational speed is provided between a pedal crank for driving the generator and the generator itself, wherein the transmission is a planetary gear set that is preferably housed at least partially inside the generator.

[0004] US 2011 / 180341 A1 discloses the features of the preamble of claim 1.

[0005] The invention is based on the objective of proposing a drive arrangement for a muscle-powered vehicle which is compact and characterized by an improved efficiency.

[0006] This problem is solved by a drive arrangement having the features of claim 1 and a vehicle having the features of claim 7. Preferred or advantageous embodiments of the invention will become apparent from the dependent claims, the following description and / or the accompanying figures.

[0007] The invention relates to a drive arrangement designed and / or suitable for a muscle-powered vehicle. In particular, the vehicle is designed as an electric bicycle, also known as an e-bike. The bicycle can generally have exactly two wheels. Alternatively, however, the vehicle can also have more than two, in particular three or exactly four wheels.

[0008] The drive assembly can be coupled to a drive module; alternatively, the drive module forms a component of the drive assembly. The drive module serves to generate an electric drive torque. The drive module preferably comprises at least one electric motor, which converts electrical energy into an electric drive torque. The drive module, and in particular the electric motor, can be connected to and / or is connected to at least one drive wheel of the vehicle. In principle, the drive module is designed as a wheel hub drive integrated into the vehicle's drive wheel. Alternatively, however, the drive module can also be arranged outside the drive wheel and / or serve as a central drive motor for one or more drive wheels. The drive wheel is generally designed as a rear wheel of the vehicle. Alternatively, however, the drive wheel can also be designed as a front wheel of the vehicle.

[0009] The drive assembly includes a generator module designed and / or suitable for generating electrical energy for the electric motor. The generator module is specifically designed separately from the drive module. For this purpose, the generator module includes a generator that can be driven by a vehicle user via pedaling. In particular, the generator produces electrical power resulting from the torque and rotational speed applied to the generator. Preferably, the vehicle user can vary the amount of electrical power depending on the pedaling force or pedaling frequency. Preferably, the drive assembly includes a control device designed to control the drive torque and / or the drive speed of the drive module depending on the pedaling force and / or pedaling frequency.Preferably, the generator is not designed to operate as a drive motor and / or can only operate in generator mode. Alternatively, the generator can be driven by an electric motor, for example to move the cranks into a specific position.

[0010] The generator module has a crank shaft designed and / or suitable for transmitting pedaling force to the generator. Specifically, a pedal crank is arranged at each end of the crank shaft, through which the pedaling force is introduced into the crank shaft. The crank shaft is rotatably mounted in the generator module. Preferably, the crank shaft, with its axis of rotation, defines a main axis of rotation for the generator module. The crank shaft runs continuously from one pedal crank to the other.

[0011] The generator module includes a gearbox designed and / or suitable for transmitting the pedaling force to the generator. The pedal crank shaft is connected to the generator via this gearbox. Specifically, the gearbox serves to increase the speed (magnitude (i) < 1), thereby increasing the rotational speed of the generator and reducing the transmitted torque.

[0012] Within the scope of the invention, it is proposed that the transmission device be designed as an eccentric transmission. In particular, the eccentric transmission has a transmission input, in particular an input element, and a transmission output, in particular an output element, wherein the pedal crank shaft is arranged on the input side and the generator on the output side. In particular, a power transmission path for transmitting the pedaling force runs from the pedal crank shaft via the eccentric transmission to the generator. For this purpose, the pedal crank shaft is guided axially through the eccentric transmission with respect to the main axis of rotation and / or arranged coaxially with the eccentric transmission.

[0013] The advantage of the invention lies particularly in the fact that the use of an eccentric gear allows for a particularly quiet transmission with a compact design. This enables the realization of a generator module characterized by its small installation space. In contrast to application-specific planetary gear stages, the associated development efforts, such as time, costs, and risks, are eliminated. Furthermore, eccentric gears allow for a continuous shaft in the center, which is a fundamental requirement for use in bicycles with crank arms on both sides.

[0014] In one embodiment of the invention, the eccentric drive comprises a roller carrier with drive rollers as a first component. The roller carrier is particularly preferably designed as a roller disk. The drive rollers are evenly distributed around the main axis on a common pitch circle. The drive rollers extend axially and / or parallel to the main axis. Furthermore, the eccentric drive comprises at least one cam disk. The cam disk has drive openings for the drive rollers and a central eccentric mounting opening. The free diameter of the drive openings is larger than the diameter of the drive rollers. In particular, the cam disk is designed as a flat disk. The cam disk has a curved shape on its outer circumference. The eccentric drive comprises a ring gear section as a second component. The ring gear section can be designed as a single piece or in multiple parts.The at least one cam disc runs along the outer circumference of the ring gear section during operation. The eccentric drive has an eccentric shaft as its output element. The eccentric shaft has at least one eccentric section, which has a circular cross-section. The eccentric section engages in the central eccentric receiving opening. Preferably, a disc bearing assembly is arranged between the eccentric section and the eccentric receiving opening to reduce friction.

[0015] The cam profile of the at least one cam disk and the inner contour of the ring gear section can, in principle, be of any design, as long as they can perform the function of the eccentric drive. However, the eccentric drive is particularly preferably designed as a cycloidal drive, wherein the outer circumference of the at least one cam disk forms a cycloidal shape.

[0016] In a further specification, the generator module is provided to have a stator and a rotor, with the eccentric shaft connected to the rotor in a rotationally fixed manner. During operation, the pedaling torque is thus transmitted to the rotor via the eccentric drive, causing the rotor to rotate relative to the stator around the main axis of rotation. In particular, the eccentric shaft is positively and / or frictionally and / or materially bonded to the rotor, preferably at least rotationally fixed. Alternatively, the eccentric shaft and the rotor can also be formed from a single piece of material. Preferably, the eccentric shaft is arranged coaxially and / or concentrically to the rotor with respect to the main axis of rotation. A generator module is thus proposed which is characterized by a particularly compact design.

[0017] In a further specific implementation, the eccentric shaft is provided with a hollow shaft section for the passage of the crank arm, the crank arm being rotatably mounted on an inner circumference of the hollow shaft section. In particular, the hollow shaft section has at least one bearing seat on its inner circumference for a bearing assembly, preferably a rolling bearing, by means of which the crank arm is rotatably supported on the hollow shaft section. Preferably, the rotor is fixedly mounted on an outer circumference of the hollow shaft section.

[0018] In a preferred embodiment, the eccentric transmission has a gear ratio between the transmission input and output of less than 1:30. Preferably, the eccentric transmission has a gear ratio between 1:30 and 1:100. Preferably, the eccentric transmission has a gear ratio of 1:50. In this way, the high pedaling torque (up to approximately 200 Nm) generated by the rider at the transmission input is converted into a lower torque at the transmission output at high speeds (in the range of 30 to 120 rpm).

[0019] In principle, the drive rollers can be rigidly mounted on the roller carrier. However, it is preferred that each drive roller has a bolt, a roller bearing, and a roller sleeve for transmitting the torque to the cam disc(s). Preferably, the roller sleeve is designed as a non-cutting and / or formed part. The bolts are fixed to the roller carrier. A roller bearing is arranged between each bolt and roller sleeve. In principle, this can be a plain bearing, but preferably the roller bearing is designed as a rolling element bearing. This design allows for quiet operation with low friction losses in the generator module.

[0020] In a preferred embodiment of the invention, the eccentric drive has two cam discs offset diametrically and / or oppositely in the plane of the discs, e.g., by 180° in the direction of rotation. The cam discs are preferably arranged axially adjacent to one another. Preferably, the cam discs are arranged in contact with each other and / or slide against each other during operation. This design reduces lateral forces in the eccentric drive.

[0021] In a further specific implementation, the generator module is provided with a housing designed and / or suitable for receiving the generator and the eccentric drive. In particular, the generator and the eccentric drive are completely enclosed within the housing. Preferably, the pedal crank shaft is guided section by section through the housing, with the pedal crank shaft being radially supported on the housing by at least one further bearing arrangement, preferably a rolling bearing. The housing can be multi-part, preferably two-part. In particular, the housing has a receiving space for receiving the eccentric drive and the generator, wherein the eccentric drive and the generator are positively locked in the housing in the axial and / or radial direction with respect to the main axis of rotation. Preferably, the stator is rigidly connected to the housing.

[0022] In a further specification, it is proposed that the eccentric gear, the pedal crank shaft, and the generator are arranged coaxially and / or concentrically with respect to the main axis of rotation. Thus, an eccentric gear is proposed which is characterized by a small axial width and a rotationally symmetrical design.

[0023] According to the invention, the roller carrier forms the input element of the transmission assembly, in particular the eccentric gear. Specifically, the roller carrier is non-rotatably connected to the pedal crank shaft. In this embodiment, the generator module can be made particularly compact. While this means the eccentric gear is operated in a virtually "reverse" direction, this is possible because the eccentric gear does not have a self-locking mechanism. In this embodiment, the ring gear section is arranged non-rotatably. For example, the ring gear section is fixed non-rotatably within the housing or is formed by the housing itself.

[0024] In a further development of the invention, the ring gear section comprises a plurality of pin sections, which are axially aligned and regularly distributed in the direction of rotation. The at least one cam disk runs on the pin sections. The pin sections are particularly preferably designed as cylindrical pins, specifically as hardened cylindrical pins, which can be inserted, for example, into bores in the housing of the generator module or, alternatively, into a rotatable carrier as a ring gear section. In this way, the function of the ring gear section can be implemented in a cost-effective and space-saving manner.

[0025] In an alternative, unused embodiment, the ring gear section forms the input element to the transmission assembly. In particular, the roller carrier is rigidly arranged. However, this embodiment results in a slightly larger overall size.

[0026] According to the invention, the pedal crank shaft has a shaft section and a shaft extension for connection to the pedal crank. The shaft section preferably runs through the generator. According to the invention, the shaft section and the shaft extension are also detachably connected to each other.

[0027] In particular, the shaft extension and the shaft section can be inserted into one another. This proposes an intermediate piece between the shaft section and the crank arm in the form of the shaft extension. In this way, both the interface to the shaft section and the interface to the crank arm can be designed independently of each other and thus functionally appropriately. Furthermore, design flexibility is created for the shaft extension, so that it can also be adapted functionally between the interfaces. It is particularly preferred that the input element is formed in one piece with the shaft extension. Thus, the gearbox input driven by the crank arm shaft is formed in one piece with the respective shaft extension. This eliminates the need for an otherwise required additional torque-transmitting connection between the shaft extension and the component representing the gearbox input.Furthermore, the shaft extension is assigned another function. For example, the shaft extension is formed as a single unit with the roller carrier or with the ring gear section.

[0028] In a preferred embodiment, the maximum outer diameter of the shaft extension is larger than the maximum outer diameter of the shaft section within a region of the generator. Alternatively or additionally, the maximum outer diameter of the shaft extension is larger than the minimum free diameter through the generator. This embodiment is based on the consideration that the generator limits the outer diameter of the crank arm shaft. On the other hand, it is advantageous for the crank arm to engage the crank arm shaft over a larger diameter. The at least or exactly two-part design allows the shaft section to be inserted into the generator and pushed through, and subsequently connected to the shaft extension, wherein the shaft extension has a larger outer diameter than the shaft section for coupling the crank arm.

[0029] In a preferred embodiment of the invention, the shaft section and the shaft extension are positively connected to each other in the circumferential direction. For example, a splined connection, particularly with teeth extending in the axial direction, can be used. Alternatively, a polygon connection can be used, in particular with a P3G profile (triangle) or a P4C profile (square). This shaft-hub connection ensures reliable torque transmission. Preferably, the shaft section and the shaft extension are screwed together in the coaxial direction. A first coaxial axle screw, which is screwed into the shaft section, is particularly preferred in this case.

[0030] In a preferred embodiment of the invention, the shaft extension has an internal thread for receiving a second coaxial axle screw for fastening the crank arm. In particular, the first coaxial axle screw and the second coaxial axle screw are arranged one behind the other in the axial direction. This creates a particularly stable crank arm shaft.

[0031] Optionally, the drive assembly includes the crank arm(s), wherein the crank arm is mounted on the shaft extension and positively connected to the shaft extension in the direction of rotation. Furthermore, the drive assembly includes the second coaxial axle screw for securing the crank arm, which is screwed into the internal thread. Preferably, a crank bolt, such as an ISIS crank bolt, is used as the second coaxial axle screw. The shaft extension ensures that sufficient radial installation space is available for the second coaxial axle screw.

[0032] On the opposite side, the pedal crank shaft has another pedal crank. Preferably, a further shaft extension is provided here, whereby in one possible embodiment the shaft section and the further shaft extension are formed as a single piece. In this embodiment, the shaft section with the integral shaft extension can be inserted section by section through the generator from one axial side and subsequently connected to the separate shaft extension. Preferably, the integrally connected shaft extension is arranged on the side facing away from the gearbox, so that on the gearbox side the shaft extension and the input element can be formed as a single piece. This allows both shaft extensions to have a larger outer diameter than the shaft section.

[0033] In another possible embodiment, the further shaft extension is detachably connected to the shaft section. In particular, the further shaft extension is identical in construction or mirror-symmetrical to the previously described shaft extension.

[0034] In a further embodiment, the generator module is directly connected to the drive module via an electrical line to provide electrical energy. In particular, the electric motor can thus be powered directly by the current generated by the generator. Alternatively, or optionally, the generator module is indirectly connected to the drive module via an energy storage module to provide electrical energy. Specifically, the energy storage module is designed as a battery, which is charged by the generator during operation and can also be charged by an external power source. In particular, the electric motor can thus be powered by the current stored in the energy storage module.

[0035] Another aspect of the invention relates to a vehicle with the drive arrangement as previously described. In particular, the vehicle is a muscle-powered vehicle, especially a bicycle, which is driven by an electric motor. The vehicle is particularly characterized in that the electrical energy required for the electric motor is generated at least partially by the rider using the generator module.

[0036] Further features, advantages, and effects of the invention will become apparent from the following description of a preferred embodiment of the invention and the accompanying figures. These figures show: Figure 1 is a schematic representation of a vehicle with a drive arrangement as an embodiment of the invention; Figure 2 is a sectional view of a generator module of the drive arrangement; Figure 3 is a three-dimensional representation of the transmission unit in the Figure 2Figure 4 shows an axial top view of the gear unit in the Figure 2 and 3 Figure 5 shows a sectional view of an alternative gear unit of the drive arrangement in the Figure 1 .

[0037] Corresponding or identical parts are each provided with the same reference symbols in the figures.

[0038] Figure 1 Figure 1 shows a highly simplified representation of a muscle-powered vehicle 1. The vehicle 1 is designed as a bicycle, which essentially consists of a frame 2, a front wheel 3 and a rear wheel 4.

[0039] Vehicle 1 has a drive arrangement 5 which serves to drive the rear wheel 4. The rear wheel 4 thus forms a drive wheel of vehicle 1, while the front wheel 3 remains undriven. Optionally, however, it can also be provided that the front wheel 3 is driven.

[0040] The drive assembly 5 comprises a generator module 6, optionally a drive module 7, and an energy storage module 8. The generator module 6 is located in the area of ​​the bottom bracket and can be driven by a vehicle user by pedaling force to generate electrical energy for the drive module 7. For this purpose, the generator module 6 has two diametrically opposed pedal cranks 9, which are set in rotation by pedaling force to generate electrical power in the generator module 6.

[0041] The bicycle has no mechanical drive connection between the pedal cranks 9 and the drive wheel 4. The generator module 6 is only electrically connected to the drive module 6 and / or the energy storage module 8 via an electrical line 10 to provide the electrical energy required for the drive module 7. The drive module 7 can, for example, be designed as a wheel hub motor integrated into the rear wheel 4, which transmits an electrical drive torque to the rear wheel 4. The drive module 7 can be supplied directly by the electrical energy generated by the generator module 6 or indirectly by the electrical energy stored in the energy storage module 8. The energy storage module 8 can be powered by the generator module 6 while riding and can also be charged by an external power source. Optionally, the electrical energy provided by the generator module 6 can be supplied to a consumer 11, e.g., a power supply unit.Light will be provided.

[0042] The Figure 2 Figure 6 shows a longitudinal section of generator module 6 along a main axis of rotation H. Generator module 6 has a pedal crank shaft 14, whose axis of rotation defines the main axis of rotation H. In an installed configuration, the pedal cranks 9 are mounted at the ends of the pedal crank shaft 14.

[0043] The generator module 6 comprises a generator 15 and a gearbox 16, both housed together in a casing 17. The generator 15 has a stator 18 and a rotor 19, with the pedal crank shaft 14 connected to a gearbox input and the rotor 19 to a gearbox output of the gearbox 16. The stator 18, however, is fixedly connected to the casing 17 and thus remains stationary. The gearbox 16 serves to transmit a pedaling torque introduced into the pedal crank shaft 14 to the generator 18 via the gearbox 16.

[0044] The transmission unit 16 is designed as an eccentric gear 20. The eccentric gear 20 is arranged coaxially with respect to the main axis of rotation H to the generator 15 and the pedal crank shaft 14 and is axially positively engaged between the generator 15 and the housing 17. The housing 17 is designed in two parts, comprising a housing base 21 which is closed axially by a housing cover 22. Both the housing base 21 and the housing cover 22 each have a central through-opening 23, 24, which serves to allow the pedal crank shaft 14 to pass through the housing 17.

[0045] The eccentric gear 20 has a roller carrier 25 as its input element, which is arranged non-rotatably with the pedal crank shaft 14. Furthermore, two cam discs 26, 27 are provided, wherein the cam discs 26, 27 have an eccentric receiving opening 48 ( Figure 3) and a plurality of off-center drive openings 49 ( Figure 3 The cam discs 26, 27 are arranged opposite each other to reduce lateral forces during operation. The roller carrier 25 has a plurality of drive rollers 28, the drive rollers 28 engaging in the drive openings 49 of the cam discs 26, 27, so that the cam discs are driven in the direction of rotation by the drive rollers 28 and thus by the roller carrier 26.

[0046] The eccentric gear 20 has a ring gear section 29, wherein the ring gear section 29 has a plurality of axially extending pin sections 50. The pin sections 50 are designed as hardened cylindrical pins that are inserted into bores in the housing 17. The outer circumference of the cam discs 26, 27 is formed in a wave shape, which engages the ring gear section 29 only section by section, offset by 180°. In particular, the wave shape is designed as a cycloidal shape.

[0047] An output element of the eccentric drive 20 is designed as a hollow shaft 30, wherein the hollow shaft 30 has two eccentric sections 31, 32, the eccentric sections 31, 32 engaging in the eccentric receiving opening of the cam discs 26, 27 via disc bearing arrangements 33, 34. The hollow shaft 30 is rotationally fixed to the rotor 19. When the pedal crank shaft 14 rotates, the roller carrier 25 also rotates, and the rotational motion is amplified. In a preferred embodiment, the eccentric drive 20 has a gear ratio between the gear input and gear output of less than 1:30. Preferably, the eccentric drive 20 has a gear ratio between 1:30 and 1:100. Preferably, the eccentric drive 20 has a gear ratio of 1:50. In this way, the high pedaling torque generated by the rider (in the range up to approx.200 Nm) at the gearbox input / input element with low speeds (in the range of 30 to 120 rpm) is converted into a lower torque with high speeds at the gearbox output / output element.

[0048] In this embodiment, the pedal crank shaft 14 has three components: a central shaft section 35 and shaft extensions 36 and 37, which are mounted at their ends onto the central shaft section 35. The shaft section 35 is coaxial with the rotor 19 and arranged in the same axial direction as the rotor 19. In particular, the shaft section 35 projects beyond the rotor 19 on both sides in the axial direction. The maximum outer diameter of the shaft section 35 is smaller than the free inner diameter of the rotor 19 and / or the hollow shaft 30. The shaft extensions 36 and 37 are mounted at their ends onto the shaft section 35. For this purpose, the shaft extensions 36 and 37 have receptacles 38 and 39 into which the respective ends of the shaft section 35 are inserted. The receptacles 38 and 39, together with the ends of the shaft section 35, form a positive-locking shaft-hub connection in the rotational direction.For example, this could be a polygon connection or a splined connection. For axial fastening and / or securing of the shaft extensions 36, 37, first axle screws 40, 41 are screwed into the shaft section 35, the screw heads of which fix the shaft extensions 36, 37 in the axial direction. Thus, the shaft extensions 36, 37 each have a first interface with the shaft section 35.

[0049] The pedal cranks 9 are mounted on the axial outer side of the shaft extensions 36, 37 and fastened by a second axle screw 42, 43, which is screwed into an internal thread 12, 13 of the shaft extension 36, 37 and whose screw head fixes the pedal crank 9 axially. Thus, the shaft extensions 36, 37 each have a second interface with the respective pedal crank 9. The first and second axle screws 40, 42 and 41, 43, respectively, are arranged axially one behind the other.

[0050] The detachable connection between the shaft extensions 36, 37 and the shaft section 35 allows the shaft extensions 36, 37 to have a larger maximum outer diameter than the shaft section 35 while still being designed for easy assembly. A further advantage is that the first and second interfaces can be designed to withstand the load without having to consider the limitation of a maximum outer diameter that must be pushed through the rotor 19 during assembly. The first and second interfaces are axially offset from each other, so that they do not influence each other during the design process.

[0051] A further advantage arises from the fact that additional functions can be implemented on the outer circumference of the shaft extensions 36, 37: The generator module 6 has bearing assemblies 44, 45, wherein the bearing assemblies 44, 45 are designed as rolling bearing assemblies, in particular as ball bearing assemblies. The bearing assemblies 44, 45 support the pedal crank shaft 14 relative to the housing 17 relative to a housing section of the housing 17. The shaft extensions 36, 37 are each designed as bearing partners of the bearing assemblies 44, 45 and each carries an inner ring of the bearing assemblies 44, 45 on their outer circumference. The respective outer ring is arranged in the housing 17.Because the outer diameter of the shaft extensions 36, 37 is larger than the outer diameter of the shaft section 35, larger diameter bearing devices 44, 45 can be used, so that together with the stable combination of shaft section 35 and shaft extension 36, 37 a higher stiffness of the bearing devices 44, 45 can be achieved.

[0052] Furthermore, the generator module 6 has sealing devices 46, 47 that seal the pedal crank shaft 14 against the housing 17 at the respective through-openings 23, 24. The sealing devices in 46, 47 run on the shaft extensions 36, 37. The shaft extensions 36, 37 thus form sealing partners for the sealing devices 46, 47. Therefore, no seals need to be incorporated inside the housing 17.

[0053] In generator module 6, the roller carrier 25 of the eccentric gear 20 is designed as a single unit with the shaft extension 36, serving as the gear input / input element. Thus, the shaft extension 36 assumes an additional function. This offers the particular advantage of eliminating the need for a shaft-hub connection between the pedal crank shaft 14 and the gear unit 16.

[0054] A standard crank axle, as used in conventional bicycles, cannot be made larger in diameter on both sides (e.g., to securely mount crank arms with, for example, ISIS splines), because centrally located components could no longer be attached. If these components were made larger in diameter, the overall outer diameter of the module would also (unnecessarily) increase, thus increasing installation space, cost, and weight.

[0055] If, for example, a corresponding DIN toothing is chosen for the crank arms, which requires a smaller diameter so that all components can be attached from the shaft ends, then specially manufactured crank arms must be used, which severely limits the selection of crank lengths, designs, and crank offset (Q-factor / “stance width”) due to the small quantity or makes it expensive.

[0056] If, instead of special crank arms, only crank adapters are attached to the continuous crank axle in order to use standard cranks (e.g. ISIS), these can only be made with a thin wall, which leads to a loss of stability and, due to the additionally required axle connection, causes higher costs.

[0057] In order to represent a stable pedal crank shaft 14 which has a small diameter in its (axial) middle, but a larger diameter at each end, it is therefore proposed to make the pedal crank shaft 14 in multiple parts (e.g. two-part or three-part).

[0058] The assembly consists (in the case of a three-part design as in the Figure 2) from shaft section 35 as a central shaft with a small diameter, which has a shaft connection at each of its ends. This can be in the form of a splined connection or a P3G polygon connection. A shaft extension 36, 37 is slipped onto each of these shaft connections and preferably axially screwed to the shaft section 35 by means of a first axle screw 40, 41. The pedal crank shaft 14 is supported by the shaft extension(s) 36, 37 and not by the shaft section 35, in order to form a stable assembly and – for the benefit of stiffness – to be able to use larger bearing arrangements 44, 45. The sealing arrangements 46, 47 as housing and cover seals are also provided running on the shaft extensions 36, 37, so that no seal inside the housing 17 is required.

[0059] The shaft ends, which extend from the generator module 6 in one piece (not radially nested as with attached adapters) and are formed as the shaft extensions 36, 37 of the pedal crank shaft 14, make it possible to use standardized ISIS crank bolts as the second axle bolts 42, 43. This would not be possible with attached adapters, as the remaining radial component wall thickness would be too small. The gearbox input / input element driven by the drive shaft can also be formed in one piece with the respective shaft extension 36, 37. This eliminates the need for an otherwise required additional torque-transmitting connection (e.g., splined connection) between the shaft extension 36 and the component representing the gearbox input / input element (saving costs, installation space, and mass).

[0060] Since the attachment of further components (gearbox parts / bearings, etc.) to the crankshaft 14 during assembly may only be possible / necessary from one side, the crankshaft 14 can alternatively be designed in two parts. In this case, the shaft section 35 and one of the two shaft extensions 36, 37 are formed as a single unit. Preferably, this is done on the side of the generator module 6 where the gearbox 16 is not located, so that on the gearbox side, the shaft extension 36 and the gearbox input / input element can be formed as a single unit. The crankshaft 14 is supported relative to the hollow shaft 30 and / or the rotor 19 by a rotor bearing assembly 51, which is arranged in the end region of the rotor 19 and is designed as a rolling element bearing.Furthermore, the pedal crank shaft 14 is supported by a roller bearing assembly 52 in the area of ​​the transmission assembly 16 against the hollow shaft 30 and / or the eccentric sections 31, 32.

[0061] The Figure 3 Figure 1 shows a schematic, three-dimensional representation of the gear assembly 16 or the eccentric gear 20, designed as a cycloidal gear. In conjunction with the representations of the Figure 2 and Figure 4The figure, which shows an axial top view of the same assembly, shows that the drive rollers 28 each have a bolt 52, the bolt 52 being fixed in a roller disc 53 of the roller carrier 25, e.g., pressed in. A roller sleeve 54 is coaxially mounted on each bolt 52, the roller sleeve 54 being supported on the bolt by a roller bearing 55. The roller bearing 55 is designed as a sliding bearing or as a rolling element bearing. The outer diameter of the drive rollers 28 and / or the roller sleeves 54 is larger than the drive openings 54, so that the roller sleeves 54 can run on the inner circumference of the drive openings 54. The roller disc 53 is formed in one piece with the shaft extension 36, thus eliminating the need for a shaft-hub connection.

[0062] To further reduce friction losses in the generator module 6, in particular in the gearbox 16 and especially in the eccentric gearbox 20, the gearbox compartment is provided with oil or grease lubrication, wherein the gearbox compartment is separated from a dry compartment for the generator and the electronics by an intermediate wall 56 and a seal 57 relative to the hollow shaft 30.

[0063] The Figure 5 shows a second embodiment of the generator module 6 in the drive arrangement 5 of the Figure 1 . In the Figure 5 A longitudinal section along the main axis of rotation H is shown, with the following only the differences to generator module 6 being discussed. Figure 2 is addressed. In contrast to generator module 6 in the Figure 2 Here, the ring gear section 29 forms the input element and / or the transmission input to the transmission unit 16 or the eccentric gear 20. The ring gear section 29 can be configured similarly to the Figure 2 by a plurality of bolt sections 50 arranged in the direction of rotation, designed in particular as hardened cylindrical pins. In the illustrated embodiment, the ring gear section 29 has a support 58, wherein the support 58 is arranged non-rotatably on the pedal crank shaft 14. However, it is also possible that the support 58 is connected to a shaft extension, such as the shaft extension 36 in the Figure 2 is designed as a single piece. Furthermore, the pedal crank axle 14 can also be designed as a two-piece or multi-piece axle, as in the Figure 2 . Reference symbol list

[0064] 1 Vehicle 2 Frame 3 Front wheel 4 Rear wheel 5 Drive assembly 6 Generator module 7 Drive module 8 Energy storage module 9 Crank 10 Cable 11 Consumer 12 Internal thread 13 Internal thread 14 Crank shaft 15 Generator 16 Gear unit 17 Housing 18 Stator 19 Rotor 20 Eccentric gear 21 Housing base 22 Housing cover 23 Through opening in housing cover 24 Through opening in housing base 25 Roller carrier 26, 27 Cam discs 28 Drive rollers 29 Ring gear section 30 Hollow shaft 31, 32 Eccentric sections 33, 34 Disc bearing assembly 35 Shaft section 36, 37 Shaft extensions 38, 39 Mounts 40, 41 First axle bolt 42, 43 Second axle screw 44, 45 Bearing devices 46, 47 Sealing devices 48 Eccentric mounting opening 49 Drive openings 50 Bolt sections 51 Rotor bearing device 52 Bolt 53 Roller disc 54 Roller sleeve 55 Roller bearing 56 Intermediate wall 57 Seal 58 Carrier H Main pivot axis

Claims

1. A drive assembly (5) for a human-powered vehicle (1) having a generator module (6) for generating electrical energy for a drive module (7) for generating an electric drive torque, wherein the generator module (6) has a generator (15) that can be driven by a vehicle user by pedal force, wherein the generator module (6) has a pedal crankshaft (14) for transmitting the pedal force from a pedal crank (9) to the generator (15), wherein the generator module (6) has a gearbox device (16) for transmitting the pedal force to the generator (15), wherein the pedal crankshaft (14) is mechanically connected to the generator (15) via the gearbox device (16) and the gearbox device (15) is designed as an eccentric gearbox (20), wherein the eccentric gearbox has a roller carrier (25) with drive rollers (28) as a first element, at least one cam disc (26, 27) with drive openings (49) and a central eccentric receiving opening (48), wherein the drive rollers (28) engage in the drive openings (49), a ring gear section (29) as a second element, wherein the cam disc (26, 27) runs with its outer circumference on the ring gear section (29), and an eccentric shaft as the output element, wherein the eccentric shaft has at least one eccentric section (31, 32), wherein the eccentric section (31, 32) engages in the central eccentric receiving opening (48), the roller carrier (25) forms the input element of the gearbox device (16), characterised in that the pedal crankshaft (14) has a shaft section (35) and a shaft extension (36) for connecting with the pedal crank (9), wherein the shaft section (35) and the shaft extension (36) are detachably connected to each other and the shaft extension (36) is formed in one piece with the input element.

2. The drive assembly (5) according to claim 1, characterized in that the drive rollers (28) each have a bolt (52), a roller bearing (55) and a roller sleeve (54), wherein the roller sleeve (54) is rotatably arranged on the bolt (52) via the roller bearing (55) and wherein the bolts (52) are fixed in the roller carrier (25).

3. The drive assembly (5) according to either one of the preceding claims 1 or 2, characterised in that the eccentric gearbox (16) has two diametrically and / or oppositely offset cam discs (26, 27).

4. The drive assembly (5) according to either one of the preceding claims 2 to 3, characterised in that the ring gear section (29) is formed by a plurality of bolt sections (50), wherein the at least one cam disc (26,27) runs on the bolt sections (50).

5. The drive assembly (5) according to any one of the preceding claims 2 to 4, characterised in that the ring gear section (29) forms the input element into the gearbox device (20).

6. The drive assembly (5) according to any one of the preceding claims, characterised by the drive module (7) and an energy storage module (8), wherein the generator module (6) for providing electrical energy is connected directly to the drive module (7) via an electrical line (10) or indirectly to the drive module (7) via an energy storage module (8).

7. A vehicle (1) having a drive assembly (5) according to any one of the preceding claims.