E-bike drive device and e-bike with oil lubrication function

Abstract

The invention relates to an e-bike drive device (1) for providing an assistive torque for a rider of an e-bike (4), wherein the e-bike drive device (1) has at least the following: - an electric motor (2) which has a motor output shaft (31); - an e-bike component (78) which is driven in order to move the e-bike (4), e.g. a bottom bracket shaft (80), a chain ring (3), or a pulley of the e-bike (4), the driven e-bike component (78) being configured so as to be driven both by means of muscle power of the rider and by means of the assistive torque of the e-bike drive device (1) in an assisting state of the e-bike drive device (1); and - a reduction gear (5), with the aid of which a torque can be transmitted from the motor output shaft (31) of the electric motor (2) to the driven e-bike component (78), the reduction gear (5) comprising an input-side gear stage (13) and an output-side gear stage (14), and the reduction gear (5) having at least one gearwheel (6) which is in contact with oil (9) as lubricant and for heat dissipation.

Description

[0001] FAZ-04 / 24-PCT 1 30.09.2025

[0002] (073)

[0003] E-bike drive unit and e-bike with oil lubrication

[0004] The present invention relates to an e-bike drive device with the features according to the preamble of claim 1. Furthermore, the invention relates to an e-bike with the features according to the preamble of claim 15.

[0005] E-bikes and their corresponding drive systems with an electric motor (referred to as "e-bike drive systems") have been around for a long time. One problem with e-bikes is the limited available installation space, as well as the requirement that the components should contribute as little as possible to the weight increase compared to a non-motorized bicycle.

[0006] These challenges are all the greater for e-bike drive systems designed and intended for at least partial placement within a bicycle frame component. These are the e-bike drive systems that form the basis of the present invention. A particularly slim and weight-saving design of the e-bike is thus possible and therefore preferred, by arranging the e-bike drive system at least partially within the down tube of the e-bike. Here, "arranged within a down tube" is intended to mean, in principle, that at least one component, preferably essential components, of the e-bike drive system are located within the down tube—or, if the down tube has openings, within the contour of the down tube. It could also be provided that the down tube has openings in some sections.Components of the e-bike drive system may protrude partially from the downtube. The particular challenge arising from such a configuration, or generally from any arrangement of the e-bike drive system in confined spaces, is that the components can heat up considerably. Therefore, heat dissipation is of paramount importance.

[0007] This is especially true since the e-bike drive unit is at least partially located within a bicycle frame component, such as the down tube. In this case, the bicycle frame itself at least partially surrounds the e-bike drive unit and can essentially enclose it like an additional housing, which can negatively impact heat dissipation and lead to significant heat buildup. (FAZ-04 / 24-PCT 2 30.09.2025)

[0008] (073) this also applies to e-bike drive arrangements which are not located inside the down tube, but are at least partially located inside another tube adjacent to a bottom bracket area, which are also addressed by the present invention.

[0009] This type of arrangement also necessitates that the e-bike drive unit be as small as possible, meaning that the waste heat is generated in a smaller space and must be dissipated over a smaller surface area. This also promotes heat buildup.

[0010] Heat buildup or insufficient heat dissipation can have a particularly negative impact on the e-bike's handling. This is because, to prevent damage to the heating components of the e-bike's drive system, the assistance provided by the drive system—intended to make riding easier or provide a more enjoyable motorized riding experience—is regularly reduced or even completely shut off. This so-called "derating," or reduction in assistance power to lower the temperature, continues until the affected components have cooled down sufficiently to allow for renewed or stronger motorized assistance for the e-bike rider.

[0011] Maximizing the efficiency of the available installation space and maximizing the performance of the components used in the e-bike drive system also improves the e-bike's economic efficiency. This increased efficiency can also improve the cost-effectiveness of e-bike production, partly because the performance of the components is fully utilized and a low weight or compact design can also positively impact the required load-bearing capacity of other e-bike components.

[0012] Against this background, the present invention aims to provide an e-bike drive device that enables improved handling while simultaneously meeting the requirements of a confined installation space. FAZ-04 / 24-PCT 3 30.09.2025

[0013] (073)

[0014] Furthermore, the task is to provide an e-bike that enables improved driving behavior and whose dimensions and the installation space required are affected as little as possible by the inclusion of an e-bike drive device.

[0015] The problem is solved with respect to an e-bike drive device with the features according to the preamble of claim 1 by the features of the characterizing portion of claim 1, and with respect to an e-bike with the features according to the preamble of claim 15 by the features of the characterizing portion of claim 15. Advantageous embodiments are the subject of the dependent claims and the following description.

[0016] The proposed e-bike drive system is designed to provide assistive torque to an e-bike rider. The e-bike drive system comprises an electric motor with a motor output shaft. It also includes a driven e-bike component (or a corresponding driven connection structure for the driven e-bike component) for propelling the e-bike. The driven e-bike component could be, for example, a bottom bracket axle, a chainring, or a pulley. The driven e-bike component is designed to be driven, in assisted mode, both by the rider's muscle power and by the assistive torque provided by the e-bike drive system.

[0017] The e-bike drive unit also includes a reduction gear for transmitting torque from the motor output shaft of the electric motor to the driven e-bike component. The reduction gear comprises an input gear stage and an output gear stage. The input gear stage is preferably located closer to the electric motor in the power flow than the output gear stage. The reduction gear includes at least one gear in contact with oil for lubrication and heat dissipation.

[0018] The term "reduction gear" refers to a transmission that reduces the input speed compared to the output speed. The input torque is increased proportionally, resulting in a higher FAZ-04 / 24-PCT 4 30.09.2025

[0019] (073)

[0020] The output torque is reduced compared to the input torque. Such gearboxes are also called reduction gearboxes. In this case, the input speed corresponds to the motor speed, and the input torque corresponds to the motor torque. The bottom bracket axle, chainring, or pulley is subjected to the output torque and rotates at the output speed of the reduction gearbox.

[0021] Preferably, the reduction gear is a fixed gear. The term "fixed gear" refers to a reduction gear that cannot be switched. The fixed gear preferably has no different gears. The e-bike drive unit is preferably gearless.

[0022] Preferably, the axis of rotation of the motor output shaft is arranged approximately perpendicular to the axis of rotation of the driven e-bike component (at least in the state installed in the e-bike) (or, considering a removed e-bike drive unit without an integral driven e-bike component: approximately perpendicular to the axis of rotation of a driven mounting structure for the driven e-bike component). Preferably, the deviation from a perfectly perpendicular arrangement is at most 10 degrees. This allows for a particularly compact design of the e-bike drive unit.Accordingly, the motor shaft rotation axis preferably has an angle of at most 10° to a plane of the driven e-bike component, wherein the plane of the driven e-bike component is the plane whose normal vector coincides with the rotation axis of the driven e-bike component (again considered in a state of the driven e-bike component connected to the e-bike drive device or in a separate state of an e-bike component with respect to the driven connection structure for the driven e-bike component).

[0023] The e-bike drive unit preferably comprises a housing. The housing preferably serves to enclose the e-bike drive unit. The reduction gear, and thus also the two gear stages, are preferably housed in this (common) housing of the e-bike drive unit. The housing can be made up of multiple parts. The housing further preferably comprises an input-side section and an output-side section. The housing can, for example, consist exclusively of these two sections. FAZ-04 / 24-PCT 5 30.09.2025

[0024] (073) The output section of the housing is preferably the section associated with the bottom bracket axle. The output section of the housing can at least largely surround the output gear stage. The output section of the housing can comprise a tube section aligned parallel to the axis of rotation of the driven e-bike component (or parallel to the axis of rotation of the driven mounting structure for the driven e-bike component). The input section of the housing can comprise a tube section aligned parallel to the motor output shaft, preferably extending longitudinally. The input section of the housing can have a smaller vertical extent or a smaller diameter than the output section of the housing. The gear stages are arranged in the housing.The electric motor is preferably arranged within the housing, but can alternatively be arranged in a separate motor housing, which is, for example, attached to the housing of the e-bike drive unit. In principle, it is conceivable that the motor housing and / or the housing of the e-bike drive unit are formed by a part of the e-bike's frame. In this case, preferably at least a part of the e-bike's frame can be part of the e-bike drive unit. However, preferably the motor housing or the housing is designed separately from the e-bike's frame and is further preferably detachably connected to the e-bike's frame.

[0025] It is also conceivable that the driven e-bike component is not an independent component of the e-bike drive system, but rather an independent component of the e-bike itself. In this case, the driven e-bike component is a separate and fundamentally independent and detachable component from the e-bike drive system. However, the e-bike drive system then has at least one driven connection structure for the driven e-bike component, which is designed for connecting to the driven e-bike component. The properties described above and below with regard to the driven e-bike component then apply to this driven connection structure, insofar as they relate to the connection with the e-bike drive system.the integration into the e-bike drive device, whose integrated component is the driven connection structure, while the driven e-bike component, as assumed in this case, is an independent component of the e-bike, separate from the e- FAZ-04 / 24-PCT 6 30.09.2025.

[0026] (073)

[0027] The e-bike drive unit is a bicycle drive system. In such a case, any descriptions of the position or relative arrangement of other components in relation to the driven e-bike component refer to the e-bike drive unit's installed state within the e-bike, or its "connected state," in which the driven e-bike component is connected to the e-bike drive unit (and to the driven mounting structure for the driven e-bike component). A concrete example of such a driven mounting structure for the driven e-bike component is an output shaft of the output gear stage, on whose outer circumference a toothed section is formed for the rotationally fixed connection or attachment of the driven e-bike component, for example, a chainring.In such an embodiment, the driven e-bike component, for example in the form of the chainring, can be provided as a separate component, fundamentally detachable from the e-bike drive device, while the output shaft or its toothing on the outer circumference, as the driven connection structure for the driven e-bike component, is a fixed integral part of the e-bike drive device.

[0028] Preferably, the e-bike drive unit or reduction gear has a total oil chamber. This total oil chamber comprises an approximately cylindrical inlet section, an approximately cylindrical outlet section, and preferably a connecting section, the connecting section of which links the inlet and outlet sections. The total oil chamber can consist of these two sections. Preferably, the axis of the inlet section is approximately perpendicular to the axis of the outlet section. This ensures that the total oil chamber has a large surface area relative to its volume, thus enabling efficient heat dissipation.The axis of the inlet-side oil chamber section can simultaneously be the axis of rotation of the motor output shaft, and the axis of the outlet-side oil chamber section can simultaneously be the axis of the bottom bracket axle. Preferably, the entire oil chamber is sealed oil-tight by the housing or parts of the housing, and preferably further by components of the e-bike drive system arranged in the housing, e.g., by a sensor, a housing cover, and / or a seal. (FAZ-04 / 24-PCT 7 30.09.2025.)

[0029] (073)

[0030] The term "cylindrical" refers to the shape of a cylinder and preferably also the shape of a portion of a cylinder. The circular surfaces of the cylinder can be perpendicular to the cylinder axis and planar, or, for example, shaped like the lateral surface of a cone or truncated cone. The term "approximately cylindrical oil chamber section" refers to a space bounded by the housing and / or by components arranged within the housing, which has an opening to the oil chamber connecting section and is approximately cylindrical. The entire space or its predominant area can be approximately cylindrical. In a broader usage within this publication, an approximately cylindrical oil chamber section is also understood to mean a space that only has a cylindrical portion, i.e., is only cylindrical in a partial area.Preferably, the radial extent of the inlet-side, approximately cylindrical oil chamber section or its cylindrical subsection is greater than its axial extent. Preferably, the radial extent of the outlet-side, approximately cylindrical oil chamber section or its cylindrical subsection is also greater than its axial extent. Both approximately cylindrical oil chamber sections or their cylindrical subsections are therefore preferably disk-shaped or partially disk-shaped. Furthermore, preferably, the axial extent of the inlet-side, approximately cylindrical oil chamber section or its cylindrical subsection is greater than the axial extent of the approximately cylindrical subsection of the outlet-side oil chamber section or its cylindrical subsection. The inlet-side disk shape or partial disk shape is therefore preferably thicker than the outlet-side one.Preferably, the radial extent of the inlet-side, approximately cylindrical oil chamber section or its cylindrical subsection is at least nearly equal to the radial extent of the approximately cylindrical section of the outlet-side oil chamber section or its cylindrical subsection. Preferably, the radial extent of the outlet-side, approximately cylindrical oil chamber section or its cylindrical subsection deviates by less than 20%, and more preferably by less than 10%, from the radial extent of the inlet-side, approximately cylindrical oil chamber section or its cylindrical subsection. The axial extent of the inlet-side, approximately cylindrical oil chamber section or its cylindrical subsection...The diameter of its cylindrical section can be in a range between 60 mm and 100 mm, preferably between 70 mm and 90 mm. FAZ-04 / 24-PCT 8 30.09.2025.

[0031] (073) mm. The radial extent of the inlet-side, approximately cylindrical oil chamber section or its cylindrical subsection can be in a range between 50 mm and 90 mm, preferably between 60 mm and 80 mm. The axial extent of the approximately cylindrical section of the outlet-side oil chamber section or its cylindrical subsection can be in a range between 10 mm and 30 mm, preferably between 15 mm and 25 mm. The radial extent of the approximately cylindrical section of the outlet-side oil chamber section or its cylindrical subsection can be in a range between 50 mm and 100 mm, preferably between 65 mm and 85 mm.

[0032] Preferably, the surface of the approximately cylindrical area of ​​the outlet-side oil chamber section, or its cylindrical subsection, approaches an outer contour of the bevel gear at least partially from at least one side, preferably while maintaining the necessary distance for the bevel gear to rotate freely. This can be achieved by forming a housing step. Preferably, the input-side gear stage is arranged at least partially within the input-side oil chamber section. Preferably, the output-side gear stage is arranged at least partially within the output-side oil chamber section.

[0033] Preferably, an input side of the reduction gear is connected to the motor output shaft of the electric motor, particularly as a single unit. More preferably, an output side of the reduction gear is connected to, or connectable to, the driven e-bike component. Preferably, the reduction gear has at least two, and more preferably exactly two, gear stages. Preferably, the input gear stage is configured for a first reduction of the speed of the motor output shaft, and the output gear stage of the two gear stages is configured for a further reduction of the speed. In an alternative embodiment, the output gear stage is not configured for changing the speed, but merely for redirecting the power flow. Preferably, the output gear stage connects to the input gear stage.An output shaft of the input-side gear stage is preferably an input shaft of the output-side gear stage. In this case, a conceptual separation between the gear stages can run transversely through this shaft. FAZ-04 / 24-PCT 9 30.09.2025.

[0034] (073)

[0035] Preferably, the input-side transmission stage comprises a planetary gear set. The planetary gear set preferably includes several gears, namely a ring gear, several planet gears, and a sun gear. The planetary gear set also preferably includes a planet carrier. The planet gears can each be mounted on the planet carrier by means of a planet gear pin of the planetary gear set. Preferably, the sun gear or the input shaft of the planetary gear set is rotationally fixed to the motor output shaft. The sun gear or the input shaft of the planetary gear set can be formed integrally with the motor output shaft.

[0036] The output stage preferably comprises a bevel gear, e.g., a bevel gear. The bevel gear preferably also comprises several gears, namely preferably a bevel pinion and a ring gear. In this document, the term "ring gear" preferably refers to the larger of the two meshing bevel gears of the bevel gear. The smaller of the two meshing bevel gears is preferably referred to as the pinion.

[0037] In this publication, the term "gear stage" refers to a gear pair within the reduction gear at which the speed or torque changes. A planetary gear is preferably considered to be exactly one gear stage, even if, as is preferred, it comprises several gear pairs.

[0038] Preferably, the e-bike drive device includes a bicycle battery or is connected to a bicycle battery of the e-bike.

[0039] It is particularly preferred that an input shaft of the bevel gear unit is non-rotatably connected to a planet carrier of the planetary gear unit. In principle, it is conceivable that a different deflection gear, e.g., a crown gear unit, is used instead of the bevel gear unit.

[0040] Preferably, an output shaft of the bevel gear unit is rotatably connected to, or already connected to, the driven e-bike component in at least one direction of rotation. Preferably, the ring gear is rotatably connected to the output shaft of the reduction gear, or the output shaft of the FAZ-04 / 24-PCT 10 30.09.2025, in at least one direction of rotation.

[0041] (073)

[0042] The bottom bracket shaft is connectable or connected to the driven e-bike component, or to the output shaft of the bevel gear unit, in a rotationally fixed manner at least in one direction.

[0043] Particularly preferred is an output shaft of the bevel gear unit arranged and configured to output the supporting torque of the e-bike drive device to the driven e-bike component without further change in speed.

[0044] Preferably, both the input side of the reduction gear - or the input-side gear stage - and the output side of the reduction gear - or the output-side gear stage - have oil as a lubricant and for heat dissipation.

[0045] In one embodiment, the input side of the reduction gear, or the input-side gear stage, also features grease as a lubricant. Preferably, a combined lubrication system using oil and grease is provided on the input side (or in the input-side gear stage), and preferably also on the output side of the reduction gear (or in the output-side gear stage). Preferably, the oil comes into contact with the grease. This allows for particularly reliable lubrication through the grease and reliable cooling through the oil. Preferably, the oil and grease are matched so that their chemical properties are compatible, meaning they can be used simultaneously or in contact with each other without adversely affecting the lubrication of the gear.Greases can be classified into consistency classes according to NLGI (National Lubricating Grease Institute) from 000 to 6. Preferably, the grease used here falls within the NLGI range of classes 1 to 4, and more preferably within classes 2 to 3. A suitable grease could be, for example, Castrol® Optitemp PL3. This grease is based on a lithium soap and a mineral oil and includes various additives that ensure good compatibility with oils, and especially gear oils, so that the lubricating properties of the oil are not negatively affected when the grease comes into contact with it. Castrol® Optitemp PL3 grease falls within the NLGI consistency range of classes 2 to 3. FAZ-04 / 24-PCT 11 30.09.2025.

[0046] (073)

[0047] Oils, on the other hand, are characterized by their viscosity at specific temperatures. The temperature range covered by the oil in the present e-bike drive unit preferably extends from -50 °C to +250 °C, more preferably from -20 °C to +150 °C, and more preferably from +40 °C to +100 °C. The temperature range preferably extends to a maximum of +70 °C, for example, if plastic components and / or plastic gears are used in the reduction gear. The viscosity of oil can be classified using viscosity grades according to SAE (Society of Automotive Engineers) and / or ISO-VG (ISO 3448). Preferably, the oil according to SAE has a low-temperature viscosity in the range of 30W to 120W, more preferably from 40W to 100W, more preferably from 60W to 80W, and / or a high-temperature viscosity in the range of 30 to 120, more preferably from 40 to 100, more preferably from 60 to 80.Preferably, the oil should be of SAE grade 70W70. Preferably, the oil should be a gear oil. Unlike engine oils, gear oils have different properties, such as reduced foaming tendency. An example of such a gear oil is Castrol® BOT 233 LVX or BOT 233 LVXQ, viscosity grade SAE 70W70 or API GL4 / 5.

[0048] Preferably, an oil can be used which has a kinematic viscosity of at least ISO VG 10 (ISO 3448), in particular at least ISO VG 15 (ISO 3448), more preferably at least ISO VG 22 (ISO 3448), more preferably at least ISO VG 68 (ISO 3448), and more preferably at least ISO VG 100 (ISO 3448). It may be particularly preferred if the kinematic viscosity of the oil used is in the range of ISO VG 10 to ISO VG 680, in particular from ISO VG 15 to ISO VG 460, more preferably from ISO VG 22 to ISO VG 320, more preferably from ISO VG 32 to ISO VG 320, and more preferably from ISO VG 68 to ISO VG 150, according to ISO 3448.

[0049] The advantages of the present invention are particularly evident when a rather thin oil is used, since the cooling lubrication throughout the entire drive, and especially the distribution of a thin oil within the drive, possibly starting from an oil bath, presents a particular challenge. This is all the more true when, according to the present disclosure, low FAZ-04 / 24-PCT 12 30.09.2025

[0050] (073)

[0051] Circumferential speeds of the oil-contacted gear predominate in the e-bike.

[0052] The viscosity of the oil used can be understood, within the scope of this disclosure, as the kinematic viscosity at 40 °C according to ISO 3448. This kinematic viscosity can be measured according to ISO 3104.

[0053] In particular, the gear in contact with oil is designed such that it rotates at a maximum speed of 400 rpm, more specifically 300 rpm, preferably 250 rpm, and more preferably 150 rpm. Preferably, the gear in contact with oil is designed such that it rotates at a maximum speed equal to that of the driven e-bike component, in particular the bottom bracket axle, chainring, or pulley of the e-bike. In particular, the gear in contact with oil is connected to the driven e-bike component, in particular the bottom bracket axle, chainring, or pulley of the e-bike, in a rotationally fixed manner. This connection may be indirect.

[0054] The gear in contact with oil is in particular a gear of the output gear stage.

[0055] Preferably, the gear in contact with oil is immersed in an oil bath, particularly exclusively in the oil bath, but no other gear is immersed. Furthermore, preferably only the gear in contact with oil and no other transmission component is immersed in the oil bath.

[0056] In particular, the oil bath is only formed along one axis or axis segment of the gear in contact with the oil, so that the oil bath does not extend over several spaced-apart gear or drive components arranged on different axes, which would potentially immerse several gear or drive components in the single oil bath. Consequently, gear components distributed across multiple shafts or shaft segments are not in immersive contact with the oil bath.

[0057] In particular, the electric motor itself is separated from an oil bath. Preferably, no electric motor components are located there, and further preferably, none are located at FAZ-04 / 24-PCT 13 30.09.2025

[0058] (073) the transmission components of a first transmission stage following the output side of the electric motor come into contact with the oil bath.

[0059] In particular, the maximum diameter of the gear in contact with oil is 140 mm, more particularly 120 mm, preferably 100 mm, further preferably 80 mm, further preferably 70 mm, further preferably 60 mm, further preferably 55 mm.

[0060] For appropriate diameters and rotational speeds of the gear in contact with oil, the present invention is of particular importance, since lubrication throughout the entire drive, especially the transport of the oil, is particularly critical, at least with regard to thinner oils, as no special centrifugal or even atomizing effects are observed with respect to the oil contacting the gear. This is all the more true if, as is preferably provided here, the rotational speed of the gear in contact with oil is selected or set such that the centrifugal acceleration acting on the gear's surface due to rotation is less than the acceleration due to gravity. In this configuration, the transport of oil proves to be particularly challenging.

[0061] In a further embodiment, the input side of the reduction gear – or the input-side gear stage – has an input-side lubricant, in particular grease, and the output side of the reduction gear – or the output-side gear stage – has oil as a lubricant and for heat dissipation. Preferably, the input side – or the input-side gear stage – and the output side of the reduction gear – or the output-side gear stage – are separated from each other, in particular sealed from each other, such that the input-side lubricant – or the lubricant of the input-side gear stage – and the oil in the output side of the reduction gear – or in the output-side gear stage – do not mix.

[0062] Preferably, the gear, preferably of the output gear stage, which is in contact with oil as a lubricant and for heat dissipation, and further preferably in the form of the ring gear, is lubricated by immersion lubrication in such a way that this gear is in an operating state of the e-bike drive device FAZ-04 / 24-PCT 14 30.09.2025

[0063] (073) partially immersed in an oil bath. An operating state of the e-bike drive unit can be any state in which the e-bike drive unit is installed in an e-bike as intended and can be operated. For example, this can also include a state in which the e-bike drive unit is installed in an e-bike as intended, but is not actively operated, but the e-bike is, for example, at rest, preferably in any orientation relative to the ground, i.e., the e-bike is lying on its side or is upside down (for example, for storage or transport purposes).

[0064] Preferably, the oil bath is arranged in a housing section of the e-bike drive unit that surrounds the output gear stage. This housing section can also surround a portion of the bottom bracket axle. Preferably, in a stationary state of the e-bike drive unit, the gear is immersed in the oil bath to a depth of between 0.1% and 5% of its diameter, relative to its maximum diameter, as viewed in a cross-sectional plane along an axis of rotation. Preferably, several gears of the e-bike drive unit are oil-lubricated. However, preferably only one gear (preferably the ring gear of the gear stage with bevel gear) is partially immersed in the oil bath during operation. The other gear(s) is / are preferably lubricated by oil supplied by the immersed gear.Preferably, the reduction gear is lubricated with oil such that oil from the oil bath in the housing section is continuously distributed during operation to the output and / or input gear stage of the reduction gear and flows back into the oil bath. Preferably, the oil also comes into contact with the housing. Heat is preferably transferable from the gear or the reduction gear to the oil and from the oil to the housing.

[0065] Due to the preferred, at least partial, arrangement of the e-bike drive unit within the downtube, the installation position differs from that of a disassembled e-bike drive unit in which, for example, the motor shaft axis of rotation and, in particular, the axes of rotation of the two gear stages, especially the axes of rotation of the planetary gear and / or the bevel gear, are horizontally aligned. (In the installation position FAZ-04 / 24-PCT 15 30.09.2025)

[0066] (073) the motor shaft axis of rotation and the axes of rotation of the planetary gear are preferably arranged parallel to an axis of the down tube and / or preferably take an angle greater than 10°, in particular greater than 20°, to a horizontal plane when the e-bike is standing on a flat and horizontal surface.

[0067] The transmission preferably has an internal chamber. This chamber may at least be limited by the housing. The internal chamber can be the entire oil reservoir.

[0068] Preferably, the housing has a filler opening. This opening is preferably used for filling the gearbox interior with oil. The e-bike drive unit preferably has an inlet closure element with which the filler opening can be closed. Preferably, the inlet closure element is removable from the filler opening for filling with oil. Preferably, in the closed position, the inlet closure element serves both to seal the gearbox interior and to vent, preferably by means of a pressure relief valve arranged in the inlet closure element. The inlet closure element may include a filler screw.

[0069] Preferably, the filling recess is arranged in a longitudinal direction extending from the output side to the input side of the reduction gear, offset forwards from an axis of rotation of the driven e-bike component, and preferably from the output shaft of the output-side gear stage.

[0070] Preferably, in a horizontal installation position with the motor output shaft's axis of rotation horizontally aligned, the filling recess is arranged lower in the vertical direction than a highest apex of the housing, in particular an output-side section of the housing.

[0071] Preferably, the head of the inlet closure element extends vertically, in order to close the filling recess (in the assembled state), to a maximum of the highest point of the housing. FAZ-04 / 24-PCT 16 30.09.2025

[0072] (073)

[0073] Preferably, the pressure relief valve remains closed as long as the pressure difference between the transmission interior and its surroundings does not exceed a predetermined value. Preferably, the pressure relief valve automatically and temporarily switches to an open state when this pressure difference is exceeded. Preferably, in the open state, the pressure relief valve provides at least one channel through which air can escape from the transmission interior. This channel preferably has a minimum cross-section with an area greater than 0.5 µm². 2 The pressure relief valve is preferably diaphragm-free.

[0074] Preferably, the pressure relief valve comprises a movable closing element, a valve seat, and a helical compression spring. Preferably, the pressure relief valve is designed such that the helical compression spring presses the closing element against the valve seat when the pressure relief valve is closed.

[0075] Preferably, the pressure relief valve has a pipe section projecting into the housing, and preferably an air inlet opening, preferably located at its free end.

[0076] If the distance between the air inlet opening and an adjacent inner wall of the housing is so large that the air inlet opening does not immerse itself in the oil bath forming in the housing in a stationary state, regardless of the orientation of the e-bike drive device, then a condition is created to prevent unintentional oil leakage from the gearbox interior.

[0077] Preferably, an oil level or oil bath forms in the stationary state of the e-bike drive device, which, further preferably, is always located below or next to the inlet opening, regardless of the orientation of the e-bike drive device, and which preferably never immerses itself in the oil.

[0078] Preferably, the distance between the air inlet opening and the adjacent inner wall of the housing is greater than 0.5 cm and, more preferably, greater than 0.7 cm.

[0079] Preferably, the distance between the air inlet opening and the nearest housing wall, or the housing wall in which the pressure relief valve is arranged, is greater than FAZ-04 / 24-PCT 17 30.09.2025

[0080] (073)

[0081] 0.5 cm or 1 cm, or adapted to the amount of oil arranged in the housing and the shape of the housing, so that regardless of the orientation of the e-bike drive device to the horizontal, it is ensured that the air inlet opening is located outside the oil bath.

[0082] Preferably, the housing has a drain recess for draining the oil from the gearbox interior. Preferably, the drain recess is closed by a drain plug, preferably a drain screw, and preferably the drain plug is removable for draining the oil from the drain recess.

[0083] Preferably, the drain recess in the installation position of the e-bike drive device is arranged offset forwards from the axis of rotation of the driven e-bike component, in particular the chainring, and preferably the output shaft of the output-side gear stage, as seen in the direction of travel of the e-bike.

[0084] Preferably, the drain opening in the horizontal installation position, with the motor output shaft's axis of rotation horizontally aligned, is positioned higher than the lowest point of the housing, particularly an output-side section of the housing, when viewed vertically. Preferably, the lowest point refers to a housing that is essentially round in cross-section, i.e., the essentially cylindrical section of the housing, with the lowest point then being the lowest apex of the housing. Preferably, the drain opening is not located precisely there, but rather to the side of it when viewed from the side.

[0085] Preferably, the filling recess and the drain recess are not aligned with each other with respect to their axes. Preferably, the axes of the filling recess and the drain recess lie in a common longitudinal plane. Preferably, the axes of the filling recess and the drain recess lie radially outside the bevel pinion, or laterally to the planet carrier or laterally to the ring gear.

[0086] In another embodiment, a drain recess designed separately for filling can also be omitted, and only a FAZ-04 / 24-PCT 18 30.09.2025

[0087] (073)

[0088] (Previously described) filling recess shall be provided, which filling recess can then be used both for filling and for draining the lubricant.

[0089] Preferably, the gear in contact with oil as a lubricant and for heat dissipation is at least one of the following gears: the ring gear, in particular of the output-side gear stage; a bevel pinion, in particular of the output-side gear stage; a planet gear, in particular of the input-side gear stage; a ring gear, in particular of the input-side gear stage; and / or a sun gear, in particular of the input-side gear stage.

[0090] Preferably, the planetary gear and / or the ring gear are designed as a plastic gear. The plastic gear can be single- or multi-component. The multi-component plastic gear can have a metal insert and / or comprise different plastics. The plastic can be fiber-reinforced. The plastic gear preferably comprises at least 30% plastic. The plastic gear preferably includes at least [number] teeth made of plastic. The metal insert can serve as a structural reinforcement element of the gear and / or form a bearing area of ​​the plastic gear.

[0091] Preferably, the diameter of the ring gear is between 60 mm and 80 mm, for example, approximately 70 mm. Preferably, the distance between the motor housing (or the housing part in which the motor is located) and the axis of the bottom bracket axle is between 60 mm and 100 mm, for example, approximately 80 mm. Preferably, the distance between the ring gear and the axis of the bottom bracket axle is between 30 mm and 70 mm, and approximately 50 mm. Preferably, the outer diameter of the bevel gear is between 50 mm and 90 mm, and approximately 70 mm.

[0092] The mean outer diameter of the bevel pinion can range between 10 and 30 mm, and is approximately 20 mm. FAZ-04 / 24-PCT 19 30.09.2025

[0093] (073)

[0094] The features disclosed in this publication in connection with the input-side gear stage may instead or additionally be features of the output-side gear stage and vice versa.

[0095] A bottom bracket axle can also be designed to be driven solely by muscle power, without motor assistance.

[0096] An e-bike according to the invention is characterized in that it has an e-bike drive device which is designed according to the above description.

[0097] The e-bike has a bicycle frame. The bicycle frame preferably includes a down tube and a seat tube. The down tube preferably connects a bottom bracket area of ​​the e-bike to a head tube of the bicycle frame.

[0098] Preferably, the downtube of the bicycle frame provides a mounting or attachment area for the e-bike drive unit in each of its two lower lateral sections. Preferably, the mounting or attachment area extends from the bottom bracket axle at an angle of more than 90 degrees, more preferably at an angle of more than 120 degrees, and more preferably at an angle of more than 130 degrees, at a distance of less than 10 cm, more preferably less than 7 cm, and more preferably less than 5 cm. The bicycle frame therefore extends close to the bottom bracket axle over a wide angular range. This allows for particularly rigid integration of the e-bike drive unit into the bicycle frame. Furthermore, it enables a particularly discreet integration of the e-bike drive unit into the bicycle frame. The downtube cross-section can be round or rectangular.The largest external dimension of the downtube in the mounting / attachment area can be less than 20 cm, preferably less than 15 cm, and more preferably less than 10 cm. This allows for particularly discreet integration of the e-bike drive unit into the bicycle frame and good aerodynamics. Preferably, the e-bike drive unit is attached to the bicycle frame using screw connections in the mounting / attachment area. This has the advantage that the forces are transferred from the housing to the bicycle frame via short paths and do not have to be excessively transmitted through the housing to the mounting point on the bicycle frame. (FAZ-04 / 24-PCT 20 30.09.2025.)

[0099] (073) a particularly inconspicuous integration of the e-bike drive device into the bicycle frame is possible.

[0100] Preferably, when the e-bike is positioned on a horizontal surface, the e-bike drive unit extends downwards from the bottom bracket axle by less than 7.5 cm, preferably at most 6 cm, more preferably at most 5 cm, and more preferably at most 4 cm, when viewed from the side. This allows for a particularly discreet integration of the e-bike drive unit into the bicycle frame and good aerodynamics.

[0101] Preferably, the e-bike has a bicycle frame with a down tube section comprising a down tube and a seat tube section comprising a seat tube. Preferably, the e-bike has a bottom bracket section in which the bottom bracket axle is mounted. In this document, the term "bottom bracket section" refers to a section of the e-bike that, viewed from the side, extends around the axis of the bottom bracket axle by a maximum of 7.5 cm, preferably a maximum of 6 cm, more preferably a maximum of 5 cm, and more preferably a maximum of 4 cm. The bottom bracket section can be, for example, entirely part of the bicycle frame. The bottom bracket section can comprise a frame section and a section of the e-bike drive unit.

[0102] Preferably, the axes of the down tube and the seat tube intersect in the bottom bracket area.

[0103] The three areas – seat tube area, down tube area, and bottom bracket area – are preferably separated from each other. The down tube area and / or the seat tube area may adjoin the bottom bracket area.

[0104] Preferably, the e-bike drive unit is partially, preferably at least the electric motor of the e-bike drive unit, and more preferably at least the input-side gear stage of the e-bike drive unit, arranged in the downtube area. Preferably, the electric motor and / or the input-side gear stage extend completely or almost completely within the downtube or a contour of the downtube. The contour of the downtube can be an imaginary continuation of the downtube with an unchanged cross-section in the area FAZ-04 / 24-PCT 21 30.09.2025

[0105] (073) of cutouts in the down tube. Alternatively, the electric motor and / or the input-side gear stage can extend completely or almost completely within the seat tube or a contour of the seat tube.

[0106] Preferably, with the exception of any recesses, the down tube has a substantially uniform cross-section at least in its lower area with respect to its longitudinal extent, preferably at least in its lower half, and more preferably at least in the lower 95%.

[0107] The cross-section of the down tube is preferably round or, for example, rectangular. The inner diameter or the largest inner dimension is preferably less than 12 cm, preferably 10 cm, preferably 9 cm, preferably 8 cm and / or greater than 3 cm.

[0108] All features described in this publication can be combined with the claimed e-bike drive device and the claimed e-bike.

[0109] The present invention is explained in detail below with reference to an exemplary embodiment and the accompanying figures. These show:

[0110] Fig. 1 shows a perspective view of an embodiment of an e-bike drive device according to the invention,

[0111] Fig. 2 shows the e-bike drive unit from Fig. 1 in a sectional view in its installed position.

[0112] Fig. 3 shows the e-bike drive unit from Fig. 1 in a sectional view in its extended position.

[0113] Fig. 4 shows a perspective view of parts of the e-bike drive unit from Fig. 1.

[0114] Fig. 5 shows a representation as in Fig. 2, enlarged and with a section plane perpendicular to it, in a top view with schematically drawn oil chamber sections, FAZ-04 / 24-PCT 22 30.09.2025

[0115] (073)

[0116] Fig. 6 enlarged, a perspective sectional view of the filler screw of the inlet closure element from Fig. 2,

[0117] Fig. 7 schematically shows an embodiment of an e-bike according to the invention.

[0118] Fig. 8 shows a more detailed perspective view of a section from Fig. 7, and

[0119] Fig. 9 is a schematic representation of the down tube cross-section of the e-bike from Fig. 7.

[0120] In the figures, unless otherwise stated, the same reference symbols denote the same components with the same function.

[0121] As can be seen, for example, in a comparison of Figures 1, 2, and 5, the embodiment of the e-bike drive device 1 shown in the figures has an electric motor 2, which has a motor output shaft 31 and an e-bike component 78 driven for moving the e-bike 4 (or a corresponding driven connection structure for the driven e-bike component 78, which can also be designed separately). In the embodiment described here, the driven e-bike component 78 is a chainring 3 and is configured to be driven, in a support state of the e-bike drive device 1, both by the rider's muscle power and by the supporting torque of the e-bike drive device 1. The axis of rotation B of the driven e-bike component 78 is identical to the axis of the bottom bracket axle 80 (when the driven e-bike component 78 is connected to the e-bike drive device 1).in a separate state of a driven e-bike component 78 relating to the driven connection structure for the driven e-bike component 78).

[0122] In principle, the driven e-bike component 78, such as the chainring 3 (see Figs. 7 and 8), can be an integral part of the e-bike drive unit 1, or alternatively, it can not be such an independent component of the e-bike drive unit, but rather a fundamentally separate component, as well as an independent component of the e-bike 4. Then the FAZ-04 / 24-PCT 23 30.09.2025

[0123] (073) The driven e-bike component 78 is a separate component that is fundamentally independent of the e-bike drive device 1 and can be detached. The e-bike drive device 1 then has at least one driven connection structure for the driven e-bike component 78, which is configured for connection with the driven e-bike component 78. The properties described above and below with regard to the driven e-bike component 78 then apply to this driven connection structure insofar as they relate to the connection with or integration into the e-bike drive device 1, whose integrated component is the driven connection structure, while the driven e-bike component 78, as assumed in this case, is an independent component of the e-bike 4, separate from or detachable from the e-bike drive device 1.A concrete example of such a driven connection structure for the driven e-bike component 78 is, for instance, an output shaft 91 of the output-side gear stage 14, on which output shaft 91 a toothed section is formed on its outer circumference for rotationally fixed connection or attachment of the driven e-bike component 78, for example, the chainring 3, as can be clearly seen in Fig. 4. In such an embodiment, the driven e-bike component 78, for example, in the form of the chainring 3, can then be provided as a separate component, fundamentally detachable from the e-bike drive device 1, while the output shaft 91 or its toothed section on the outer circumference, as a driven connection structure for the driven e-bike component 78, is a fixed integral part of the e-bike drive device 1. In this case of a fundamentally separate driven e-bike component 78, the preceding orAny subsequent descriptions of the position or arrangement of other components in relation to the driven e-bike component 78 refer to a state of the e-bike drive device 1 installed in the e-bike 4 or to a "connected state" in which the driven e-bike component 78 is also connected to the e-bike drive device 1 (and to the driven connection structure for the driven e-bike component 78) (as shown, for example, in Fig. 5).

[0124] The e-bike drive device 1 also has a reduction gear 5 for transmitting a torque from the motor output shaft 31 of the electric motor 2 FAZ-04 / 24-PCT 24 30.09.2025

[0125] (073) to the e-bike component 78. The reduction gear 5 is a fixed gear and comprises an input-side gear stage 13 and an output-side gear stage 14. The input-side gear stage 13 is located closer to the electric motor 2 in the power flow than the output-side gear stage 14. The reduction gear 5 has at least one gear 6 in contact with oil 9 as a lubricant and for heat dissipation.

[0126] The axis of rotation A of the motor output shaft 31 is arranged perpendicular to the axis of rotation B of the driven e-bike component 78 (in a state of the driven e-bike component 78 connected to the e-bike drive device 1, for example in an installation position in the e-bike 4; or otherwise in a separate state of a driven e-bike component 78 approximately perpendicular to the axis of rotation of the driven connection structure for the driven e-bike component 78).

[0127] The reduction gear 5 has a total oil chamber 120. This oil chamber comprises an approximately cylindrical inlet-side oil chamber section 122, an approximately cylindrical outlet-side oil chamber section 124, and an oil chamber connecting section 126 that links the inlet-side oil chamber section 122 and the outlet-side oil chamber section 124 (Figs. 2 and 5). The outlet-side oil chamber section 124 is not entirely cylindrical, but only has a cylindrical portion. The inlet-side oil chamber section 122 is disc-shaped, and the cylindrical portion of the outlet-side oil chamber section 124 is partially disc-shaped. The inlet-side oil chamber section 122 and the outlet-side oil chamber section 124 are each roughly and schematically illustrated by dashed rectangles in Fig. 5.

[0128] The axis D of the inlet-side oil chamber section runs approximately perpendicular to the axis E of the outlet-side oil chamber section. The axis D of the inlet-side oil chamber section is simultaneously the axis of rotation A of the motor output shaft, and the axis E of the outlet-side oil chamber section is simultaneously the axis of the bottom bracket axle.

[0129] The radial extent of the inlet-side cylindrical oil chamber section 122 is almost equal to the radial extent of the cylindrical portion of the outlet-side oil chamber section 124. The axial extent of the FAZ-04 / 24-PCT 25 30.09.2025

[0130] (073) The cylindrical portion of the outlet-side oil chamber section lies in a range between 10 mm and 30 mm. While maintaining the necessary distance for free rotation of the bevel gear, the surface of the cylindrical portion of the outlet-side oil chamber section approaches an outer contour of the bevel gear 98 from one side, thereby forming a housing step R (Fig. 1).

[0131] The input-side gear stage 13 has an output shaft 88 and is at least partially located in the input-side oil chamber section 122. The output-side gear stage 14 has an input shaft 90 and is at least partially located in the output-side oil chamber section 124.

[0132] An input side 84 of the reduction gear 5 is connected to the motor output shaft 31 of the electric motor 2 as a single unit. An output side 86, or an output shaft 94 of the reduction gear 5 located therein, or an output shaft of the bevel gear 96, is rotationally fixed to the driven e-bike component 78. The ring gear 98 is rotationally fixed to the output shaft 94 of the reduction gear 5, or to the output shaft of the bevel gear 96, at least in one direction of rotation.

[0133] The input-side gear stage 13 is formed by a planetary gear set 15. The output-side gear stage 14 is formed by a bevel gear set 30. An input shaft 92 of the bevel gear set is non-rotatably connected to a planet carrier 28 of the planetary gear set 15 (Fig. 4).

[0134] The ring gear 98 is rotationally fixed to the output shaft 94 in at least one direction of rotation. The bottom bracket shaft 80 is rotationally fixed to the driven e-bike component 78 and the output shaft of the bevel gear 96 in at least one direction of rotation, at least when the e-bike drive unit 1 is installed in the e-bike 4. The input shaft 100 of the planetary gear 15 is formed integrally with the motor output shaft 31 and provides the sun gear 25 of the planetary gear.

[0135] Both the input gear stage 13 and the output gear stage 14 contain oil for lubrication and heat dissipation. FAZ-04 / 24-PCT 26 30.09.2025

[0136] (073)

[0137] An oil bath 24 is arranged in a housing section 7 surrounding the output gear stage 14. The housing 8 has a filling recess 32 for filling the gearbox interior 102 with oil 9. This recess can be closed by means of an inlet closure element 104, namely a filling screw 33. In the closed state, the inlet closure element 104 serves both to seal the gearbox interior 102 and simultaneously to vent, by means of a pressure relief valve 106 arranged in the inlet closure element 104.

[0138] In an installation position of the e-bike drive device 1 shown, for example, in Fig. 2, the filling recess 32 is arranged offset forwards from a rotation axis B of the driven e-bike component 78 (as well as the output shaft 91 of the output-side gear stage 14) when viewed in the direction of travel of the e-bike.

[0139] In a horizontal installation position shown in Fig. 3, with the motor output shaft 31's axis of rotation A oriented horizontally, the filling recess 32 is arranged, viewed vertically, lower than the highest apex 112 of an outlet-side section 114 of the housing 8, which outlet-side section 114 is at least partially cylindrical or, viewed in cross-section, essentially circular. A head 116 of the inlet closure element 104, for closing the filling recess 32, extends, viewed vertically, to a maximum extent to the highest apex 112 of the housing 8.

[0140] The pressure relief valve 106, shown in more detail in Fig. 6, is in a closed state as long as the pressure difference between the gearbox interior 102 and the environment does not exceed a predetermined value. If this pressure difference is exceeded, the pressure relief valve 106 automatically and temporarily switches to an open state. In the open state, the pressure relief valve 106 provides several channels through which air can escape freely from the gearbox interior 102. Each of the channels has a minimum cross-sectional area greater than 0.5 pm. 2 The pressure relief valve 106 is diaphragm-free. One of the channels is indicated by a dashed arrow in Fig. 6, even though the closed state of the pressure relief valve 106 is shown there. The pressure relief valve 106 comprises a movable closing element 128, a valve seat 130, and a helical compression spring 132. The helical compression spring 132 FAZ-04 / 24-PCT 27 30.09.2025

[0141] (073) presses the closing element 128 against the valve seat 130 from the inside in a sealing manner in the closed state of the pressure relief valve 106.

[0142] The pressure relief valve 106 has a pipe section 134 projecting into the housing 8, with an air inlet opening 136 preferably arranged at its free end. A dirt-repellent perforated plate 138 is arranged at the opposite end.

[0143] Figures 3 and 6 show the distance F of the air inlet opening 136 to an adjacent inner wall of the housing. This distance is so large that, regardless of the orientation of the e-bike drive unit 1, the air inlet opening 136 does not immerse itself in the oil bath 24 forming in the housing 8 when at rest.

[0144] The housing 8 has a drain recess 34 for draining the oil 9 from the gearbox interior 102 and a drain closure element 105, namely a drain screw.

[0145] The filling recess 32 is arranged in a longitudinal direction extending from the output side 86 to the input side 84 of the reduction gear, offset forward from a rotation axis B of the driven e-bike component 78, and preferably from the output shaft 91 of the output-side gear stage 14.

[0146] As Fig. 3 also shows, in the horizontal position with the motor output shaft 31's axis of rotation A oriented horizontally, the drain opening 34 is located higher, when viewed vertically, than the lowest point P of the output-side section 114 of the housing. While the drain opening 34 can extend below the lowest point P, the opening provided by the drain opening 34, as viewed from the inside of the housing 8, is located above this lowest point P. The lowest point P refers to the essentially closed area of ​​the housing 8, which is substantially cylindrical in the output-side section 114 and the affected area. The lowest point P is opposite the apex 112. FAZ-04 / 24-PCT 28 30.09.2025

[0147] (073)

[0148] As shown, for example, in Figures 2 and 3, the filling recess 32 and the draining recess 34 are not aligned with each other with respect to their axes. The axes of the filling recess 32 and the draining recess 34 lie in a common longitudinal section plane, namely the plane of the image in Figures 2 and 3, and laterally to the planet carrier 28 and laterally to the ring gear 98. The axes of symmetry of the filling recess 32 and the draining recess 34 run vertically. The axis of symmetry of the filling recess 32 is offset in the horizontal direction from the axis of symmetry of the draining recess 34.

[0149] At least the ring gear 98 and the bevel pinion 27 are in contact with oil 9 as a lubricant and for heat dissipation. As Figures 2 and 4 show, only one gear 6, namely the ring gear 98, is partially immersed in the oil bath 24 during an operating state of the e-bike drive unit 1. The bevel pinion is lubricated by oil passed on from the immersed gear 6. The gears of the planetary gear set 15 can also be lubricated by oil passed on from the immersed gear 6.

[0150] The planet gears 23 and / or the ring gear 26 have plastic components or are made of plastic.

[0151] The distance H of the motor housing, or of that housing part of the common housing 8 in which the motor 2 is arranged, to the axis of the bottom bracket shaft is approximately 80 mm. The distance S of the ring gear to the axis of the bottom bracket shaft is approximately 50 mm (Fig. 3).

[0152] The embodiment of the e-bike 4 shown in Fig. 7 has an e-bike drive unit 1, which is designed according to the description above. The e-bike 4 has a bicycle frame 16. The e-bike 4 has a bottom bracket area 140. The bicycle frame 16 has a down tube area 142 comprising a down tube 17 and a seat tube area 144 comprising a seat tube 18.

[0153] The downtube 17 provides a mounting or attachment area 146 for the e-bike drive unit 1 (Fig. 8). The bottom bracket area 140 comprises a frame section and a section of the e-bike drive unit 1, as shown by way of example in Fig. 8. The part provided by the bicycle frame 16 of FAZ-04 / 24-PCT 29 30.09.2025

[0154] (073)

[0155] The bottom bracket area 140 forms the receiving or fastening area 146, in which the screw connections 147 for fastening the e-bike drive device 1 to the bicycle frame 16 are arranged.

[0156] The axes of the down tube 17 and the seat tube 18 intersect in the bottom bracket area 140. The three areas – bottom bracket area 140, seat tube area 144, and down tube area 142 – are separated from each other. The down tube area 142 and the seat tube area 144 border the bottom bracket area 140. Viewed from the side, the bottom bracket area 140 extends in a circumferential area with a radius of no more than 7.5 cm around the bottom bracket axle.

[0157] The e-bike drive unit 1 is partially, or more precisely, at least the electric motor 2 and the input-side gear stage 13 of the e-bike drive unit 1 are, located in the down tube area 142. The electric motor 2 and the input-side gear stage 13 extend completely within the contour of the down tube 17.

[0158] With the exception of any cutouts, the down tube 17 has a substantially constant cross-section, at least in its lower area, with respect to its longitudinal extent.

[0159] As shown in Fig. 9, the cross-section of the lower tube is rectangular, with rounded corners, contrary to what is shown. The largest internal dimension T is less than 10 cm.

[0160] FAZ-04 / 24-PCT 30 September 30, 2025 (073)

[0161] Reference numeral list 104 Inlet closure element

[0162] 105 Outlet closure element

[0163] 1 E-bike drive unit 106 Overpressure valve

[0164] 2 Electric motor 112 highest point of the housing

[0165] 3 chainring 114 output side section of the Ge¬

[0166] 4 e-bike houses

[0167] 5 Reduction gear 116 Head of the inlet closure element

[0168] 6 gear 120 total oil space

[0169] 7 Housing section 122 inlet-side oil chamber section

[0170] 8 Housing 124 Outlet-side oil chamber section

[0171] 9 Oil 126 Oil space connection section

[0172] 13 input-side gear stage 128 locking element

[0173] 14 output gear stage 130 valve seat

[0174] 15 planetary gear 132 helical compression spring

[0175] 16 bicycle frames, 134 tube sections

[0176] 17 Down tube 136 Air inlet opening

[0177] 18 Seat tube 138 Perforated sheet metal

[0178] 23 planetary gear 140 bottom bracket area

[0179] 24 Oil bath 142 Lower tube area

[0180] 25 sun wheel 144 seat tube area

[0181] 26 Ring gear 146 Mounting or fastening area

[0182] 27 bevel pinions, 147 screw connections

[0183] 28 planetary carriers

[0184] 30 Angle gear A Rotation axis of the motor output shaft

[0185] 31 Motor output shaft B Axis of rotation of the driven e-bike

[0186] 32 Filling recess component

[0187] 33 Filler screw D Axis of the inlet side oil chamber¬

[0188] 34 Drain recess section

[0189] 78 driven e-bike component E axle of the output oil chamber¬

[0190] 80 bottom bracket shaft section

[0191] 84 Entrance side F Distance of the air inlet opening to ei¬

[0192] 86 Exit side of adjacent inner wall of housing

[0193] 88 Output shaft of the input-side G direction of travel

[0194] Gear stage H Distance of the motor housing to

[0195] 90 Input shaft of the output side axle of the bottom bracket shaft

[0196] Gear stage P lowest point of the housing

[0197] 91 Output shaft of the output-side R Housing stage Gear stage S Distance of the ring gear to the axis of the

[0198] 92 Input shaft of the bevel gear unit bottom bracket shaft

[0199] 94 Output shaft of the bevel gear T largest inner dimension

[0200] 96 Bevel gear U axial extent of the cylindrical

[0201] 98 Ring gear section of the output side oil

[0202] 100 Input shaft of the planetary gear space section

[0203] 102 Gearbox interior

Claims

FAZ-04 / 24-PCT 1 30.09.2025 (073) Patent claims 1. E-bike drive device (1) for providing assisting torque to a rider of an e-bike (4), wherein the e-bike drive device (1) comprises at least the following: - an electric motor (2) which has a motor output shaft (31); - an e-bike component (78) driven to propel the e-bike (4), e.g. a bottom bracket axle (80), a chainring (3) or a pulley of the e-bike (4), wherein the driven e-bike component (78) is configured to be driven in a support state of the e-bike drive device (1) both by the rider's muscle power and by the supporting torque of the e-bike drive device (1); - a reduction gear (5) for transmitting a torque from the motor output shaft (31) of the electric motor (2) to the driven e-bike component (78), wherein the reduction gear (5) comprises an input-side gear stage (13) and an output-side gear stage (14); characterized in that the reduction gear (5) has at least one gear (6) in contact with oil (9) as a lubricant and for heat dissipation.

2. E-bike drive device (1) according to claim 1, characterized in that the reduction gear (5) has a total oil chamber (120), wherein the total oil chamber (120): - an approximately cylindrical, inlet-side oil chamber section (122), - an approximately cylindrical, outlet-side oil chamber section (124), and - has an oil space connection section (126), FAZ-04 / 24-PCT 2 30.09.2025 (073) wherein the oil space connecting section (126) connects the inlet oil space section (122) and the outlet oil space section (124), and wherein the axis (D) of the inlet oil space section (122) is approximately perpendicular to the axis (E) of the outlet oil space section (124).

3. E-bike drive device (1) according to claim 1 or 2, characterized in that an input side (84) of the reduction gear (5) is connected to the motor output shaft (31) of the electric motor (2) and an output side (86) of the reduction gear (5) is connected or connectable to the driven e-bike component (78), wherein the reduction gear (5) is configured from the input side (84) to the output side (86) to reduce the rotational speed of the motor output shaft (31), wherein the input-side gear stage (13) is configured to first reduce the rotational speed of the motor output shaft (31) and the output-side gear stage (14) is configured to further reduce the rotational speed, wherein, preferably, the output-side gear stage (14) connects to the input-side gear stage (13) and an output shaft (88) of the input-side gear stage (13) connects to an input shaft (90) of the output gear stage (14) is.

4. E-bike drive device (1) according to claim 3, characterized in that the input-side gear stage (13) is a planetary gear (15) and / or the output-side gear stage (14) is a bevel gear (30), in particular a bevel gear, wherein, preferably, an input shaft (92) of the bevel gear is rotationally fixed to a planet carrier (28) of the planetary gear (15). FAZ-04 / 24-PCT 3 30.09.2025 (073) 5. E-bike drive device (1) according to claim 4, characterized in that an output shaft of the bevel gear drive (96) can be connected or is connected to the driven e-bike component (78) in a rotationally fixed manner at least in one direction of rotation, and / or the bottom bracket shaft (80) can be connected or is connected to the driven e-bike component (78) in a rotationally fixed manner at least in one direction of rotation.

6. E-bike drive device (1) according to claim 4 or 5, characterized in that an input shaft (100) of the planetary gear (15) is rotationally fixed to the motor output shaft (31) or is formed integrally with the motor output shaft (31).

7. E-bike drive device (1) according to one of claims 3 to 6, characterized in that both the input side (84) of the reduction gear and the output side (86) of the reduction gear (5) have oil as a lubricant and for heat dissipation, wherein, preferably, the input side (84) of the reduction gear (5) also has grease as a lubricant and at least in the input side (84), preferably also in the output side (86) of the reduction gear (5), a combined lubrication by means of the oil (9) and the grease is provided.

8. E-bike drive device (1) according to one of claims 3 to 6, characterized in that the input side (84) of the reduction gear (5) has an input-side lubricant, in particular grease, and the output side (86) of the reduction gear has oil (9) as a lubricant and for heat dissipation, wherein, preferably, the input side (84) and the output side (86) of the reduction gear (5) are separated from each other, in particular sealed from each other, such that the input-side FAZ-04 / 24-PCT 4 30.09.2025 (073) Do not mix the lubricant and the oil (9) in the output side (86) of the reduction gear (5).

9. E-bike drive device (1) according to one of claims 1 to 8, with a housing (8) for surrounding the e-bike drive device (1), characterized in that the gear (6) in contact with oil (9) as a lubricant and for heat dissipation, preferably of the output-side gear stage (14), is oil-lubricated by immersion lubrication in such a way that the gear (6) is partially immersed in an oil bath (24) in an operating state of the e-bike drive device (1), wherein, preferably, the oil bath (24) is arranged in a housing section (7) of the housing (8) surrounding the output-side gear stage (14).

10. E-bike drive device (1) according to one of claims 1 to 9, with a housing (8) for surrounding the e-bike drive device (1), characterized in that the housing (8) has a filling recess (32) for filling the oil (9) into a gearbox interior (102), wherein the filling recess (32): - is placed in a closed state with an inlet closure element (104), wherein the inlet closure element (104) is removable from the filling recess (32) for filling with the oil (9) and, in the closed state, is designed both to seal the gearbox interior (102) and simultaneously to vent, preferably by means of a pressure relief valve (106) arranged in the inlet closure element (104); and / or - in an installation position of the e-bike drive device (1) viewed in the direction of travel (G) of the e-bike (4) from a rotational axis (B) of the driven e-bike component (78), and preferably from the output shaft (90) of the output-side gear stage (14), from FAZ-04 / 24-PCT 5 30.09.2025 (073) is arranged offset forward; and / or - in a horizontal installation position with the rotation axis (A) of the motor output shaft (31) horizontally aligned, viewed in the vertical direction, is arranged lower than a highest apex (112) of the housing (8); preferably, wherein a head (116) of one / the The inlet closure element (104) extends in the vertical direction to the highest point (112) of the housing (8) for placing the filling recess (32) in a closed state.

11. E-bike drive device (1) according to claim 10, characterized in that the pressure relief valve (106) comprises a movably mounted closing element (128), a valve seat (130) and a helical compression spring (132), wherein the helical compression spring (132) presses the closing element (128) against the valve seat (130) in the closed state of the pressure relief valve (106), wherein, preferably, the pressure relief valve (106) has a pipe section (134) projecting into the housing (8), preferably with an air inlet opening (136) preferably arranged at its free end, wherein, preferably, the distance (F) of the air inlet opening (136) to an adjacent inner wall of the housing is such that, regardless of the orientation of the e-bike drive device (1), the air inlet opening (136) does not enter the oil bath (24) forming in the housing (8) in a resting state. immerses, preferably,the distance (F) of the air inlet opening (136) to the adjacent inner wall of the housing is greater than 0.5 cm, preferably greater than 0.7 cm. FAZ-04 / 24-PCT 6 30.09.2025 (073) 12. E-bike drive device (1) according to one of claims 1 to 11, with a housing (8) for surrounding the e-bike drive device, characterized in that the housing (8) has a drain recess (34) for draining the oil (9) from a transmission interior (102), wherein the drain recess (34) is placed in a closed state by means of a drain closure element (105), wherein the drain closure element (105) is removable for draining the oil (9) from the drain recess (34), and wherein the drain recess (34): - in an installation position of the e-bike drive device viewed in the direction of travel (G) of the e-bike, is arranged offset forward from a rotational axis (B) of the driven e-bike component, in particular the chainring (3), and preferably the output shaft (91) of the output-side gear stage; and / or - in a horizontal installation position with the motor output shaft (31) horizontally aligned, viewed in the vertical direction higher than a lowest point (P) of the housing, in particular of an output-side section (114) of the housing.

13. E-bike drive device (1) at least according to claims 10 and 12, characterized in that, in a horizontal installation position with the motor output shaft (31) horizontally aligned, the filling recess (32) and the draining recess (34) are not aligned with each other with respect to their axes, wherein, preferably, the axes of the filling recess (32) and the draining recess (34) lie in a common longitudinal section plane. FAZ-04 / 24-PCT 7 30.09.2025 (073) 14. E-bike drive device (1) according to one of claims 1 to 13, wherein the gear (6) in contact with oil (9) as lubricant and for heat dissipation is at least one of the following gears: - a ring gear (98), in particular one of the output gear stage (14); - a bevel pinion (27), in particular of one / the output gear stage (14); - a planet gear (23), in particular one of the input gear stage (13); - a ring gear (26), in particular one of the input-side gear stages (13); and / or - a sun gear (25), in particular of an input gear stage (13); preferably wherein the planet gear (23) and / or the ring gear (26) is made of plastic or consists of plastic.

15. E-bike (4) characterized by an e-bike drive device (1) according to one of claims 1 to 14, wherein, preferably, the e-bike (4) has a bicycle frame (16) with a down tube (17) and the electric motor (2) and / or the input-side gear stage (13) are arranged in the down tube (17) or within the contour of the down tube (17).

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