E-bike drive unit and e-bike with oil lubrication

The e-bike drive device with a reduction gear and oil chamber addresses heat buildup in confined spaces, ensuring efficient heat dissipation and lubrication, thereby maintaining performance and efficiency.

DE102024128254B4Active Publication Date: 2026-04-23PORSCHE EBIKE PERFOMANCE GMBH
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Patent Information

Authority / Receiving Office
DE · DE
Patent Type
Patents
Current Assignee / Owner
PORSCHE EBIKE PERFOMANCE GMBH
Filing Date
2024-09-30
Publication Date
2026-04-23

AI Technical Summary

Technical Problem

E-bike drive units face challenges in confined spaces within bicycle frames, leading to significant heat buildup and reduced performance due to insufficient heat dissipation, which affects handling and efficiency.

Method used

An e-bike drive device with a reduction gear system incorporating an oil chamber for lubrication and heat dissipation, featuring a fixed gear design and a total oil chamber with cylindrical sections to maximize surface area for efficient heat transfer, using compatible lubricants like oil and grease to maintain performance.

Benefits of technology

The solution effectively dissipates heat and maintains performance by ensuring reliable lubrication, reducing the need for derating and enhancing the e-bike's driving experience and efficiency.

✦ Generated by Eureka AI based on patent content.

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Abstract

E-bike drive device (1) for providing assistive 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) by means 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) wherein the reduction gear (5) comprises an input-side gear stage (13) and an output-side gear stage (14); wherein the reduction gear (5) has at least one gear (6) in contact with oil (9) as lubricant and for heat dissipation.
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Description

[0001] The present invention relates to an e-bike drive device for providing assistive torque to a rider of an e-bike, comprising a reduction gear with a total oil chamber containing oil as a lubricant and for heat dissipation. The invention further relates to an e-bike with a corresponding e-bike drive device.

[0002] 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.

[0003] These challenges are all the greater for e-bike drive units designed and intended for at least partial installation within a bicycle frame component. These are the e-bike drive units 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 unit 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 unit 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 overheat significantly. Therefore, heat dissipation is of paramount importance.

[0004] This is particularly relevant because the e-bike drive unit is located at least partially 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. This principle also applies to e-bike drive units that, while not located within the down tube, are at least partially located within another tube adjacent to the bottom bracket area, which are also addressed by the present invention.

[0005] 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.

[0006] DE 69825188 T2 discloses an auxiliary drive and reduction gear device for bicycles. Furthermore, DE 10 2014 100 786 A1 discloses a drive mechanism for an electric bicycle. EP 0 636 538 A1 also discloses an electrically powered vehicle with a planetary gear. EP 0 686 548 A2 also discloses a motor-assisted bicycle. EP 3 878 726 A1 also discloses a drive unit for a bicycle.

[0007] 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.

[0008] 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.

[0009] Against this background, the present invention aims to provide an e-bike drive device that enables improved driving performance while simultaneously meeting the requirements of a confined installation space.

[0010] Furthermore, the task is to provide an e-bike that enables improved driving behavior and whose dimensions and installation space are affected as little as possible by the inclusion of an e-bike drive device.

[0011] The problem is solved with respect to an e-bike drive device by an e-bike drive device having the features of claim 1 and with respect to an e-bike by an e-bike having the features of claim 12. Advantageous embodiments are the subject of the dependent claims and the following description.

[0012] The proposed e-bike drive system is designed to provide assistive torque to an e-bike rider. The e-bike drive system includes 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.

[0013] 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.

[0014] The term "reduction gear" refers to a gearbox that reduces the input speed compared to the output speed. The input torque is increased proportionally, resulting in a higher output torque compared to the input torque. Such gearboxes are also called reduction gears. 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 gear.

[0015] 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.

[0016] 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).

[0017] 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 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. The output-side section of the housing is preferably the section associated with the bottom bracket axle. The output-side section of the housing can at least largely enclose the output-side gear stage. The output-side section of the housing can include 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-side section of the housing can comprise a pipe section, preferably longitudinally extending, aligned parallel to the motor output shaft. The input-side section of the housing can have a smaller vertical extent or diameter than the output-side section of the housing. The gear stages are arranged within the housing. The electric motor is preferably also 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 part of an e-bike's bicycle frame can be part of the e-bike's drive system. Preferably, however, the motor housing or housing is designed separately from the e-bike's bicycle frame and is further preferably detachably connected to the e-bike's bicycle frame.

[0018] 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 system refers to the driven connection structure as an integrated component, while the driven e-bike component, as assumed in this case, is an independent component of the e-bike, separate from the e-bike 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 a state of the e-bike drive system installed in the e-bike, or a "connected state," in which the driven e-bike component is also connected to the e-bike drive system (and to the driven connection structure for the driven e-bike component).A concrete example of such a driven connection structure for the driven e-bike component is an output shaft of the output-side 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 unit, while the output shaft or its toothed section 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 unit.

[0019] As proposed, 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 a connecting section, the connecting section linking the inlet and outlet sections. The total oil chamber can consist of these two sections. The axis of the inlet section is proposed to be approximately perpendicular to the axis of the outlet section. This configuration 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 thereof, and preferably also by components of the e-bike drive system arranged within the housing, e.g., by a sensor, a housing cover, and / or a seal. 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 may be approximately cylindrical. In a broader usage within this publication, an approximately cylindrical oil chamber section also includes a space that only has a cylindrical portion, i.e., is cylindrical only in a partial area. Preferably, the radial extent of the inlet-side approximately cylindrical oil chamber section or its cylindrical portion is greater than its axial extent. Preferably, the radial extent of the outlet-side approximately cylindrical oil chamber section or its cylindrical portion is also greater than its axial extent.Both approximately cylindrical oil chamber sections, or their cylindrical subsections, are therefore preferably disc-shaped or partially disc-shaped. Furthermore, the axial extent of the approximately cylindrical oil chamber section or its cylindrical subsection on the inlet side is preferably greater than the axial extent of the approximately cylindrical section of the outlet oil chamber section or its cylindrical subsection. The disc shape or sub-disc shape on the inlet side is therefore preferably thicker than that on the outlet side. Furthermore, the radial extent of the approximately cylindrical oil chamber section or its cylindrical subsection on the inlet side is preferably at least nearly equal to the radial extent of the approximately cylindrical section of the outlet oil chamber section or its cylindrical subsection. Preferably, the radial extent of the approximately cylindrical oil chamber section on the outlet side deviates from this.The radial extent of the inlet-side approximately cylindrical oil chamber section or its cylindrical subsection differs from the radial extent of the inlet-side approximately cylindrical oil chamber section or its cylindrical subsection by less than 20%, more preferably by less than 10%. The axial extent of the inlet-side approximately cylindrical oil chamber section or its cylindrical subsection can be in a range between 60 mm and 100 mm, preferably between 70 mm and 90 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 area of ​​the outlet-side oil chamber section or its cylindrical subsection can be in a range between 60 mm and 100 mm, preferably between 70 mm and 90 mm.The diameter of its cylindrical section can be 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 or its cylindrical section can be between 50 mm and 100 mm, preferably between 65 mm and 85 mm.

[0020] 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.

[0021] As proposed, an input side of the reduction gear is connected to the motor output shaft of the electric motor, and in particular, these two components are formed as a single unit. As proposed, an output side of the reduction gear is connected, or connectable, to the driven e-bike component. Preferably, the reduction gear has at least two, and in particular exactly two, gear stages. As proposed, the input gear stage is configured to first reduce the speed of the motor output shaft, and the output gear stage of the two gear stages is configured to further reduce the speed. In an alternative embodiment, the output gear stage is not configured to change the speed, but merely to redirect the power flow. As proposed, the output gear stage connects to the input gear stage.The proposed output shaft of the input-side gear stage is 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] Preferably, the e-bike drive device includes a bicycle battery or is connected to a bicycle battery of the e-bike.

[0026] 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.

[0027] Preferably, an output shaft of the bevel gear unit is rotatably 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 bevel gear unit in at least one direction of rotation. Further preferably, the bottom bracket shaft is rotatably connected to the driven e-bike component or the output shaft of the bevel gear unit in at least one direction of rotation.

[0028] 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.

[0029] As proposed, 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 - contain oil as a lubricant and for heat dissipation.

[0030] The proposed design incorporates grease as a lubricant on the input side of the reduction gear, or in the input-side gear stage. Furthermore, the proposed design incorporates a combined lubrication system using both oil and grease 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 formulated to be chemically 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 class range of 2 to 3.

[0031] 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 can preferably extend 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). 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.

[0032] 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.

[0033] Preferably, the gear, preferably of the output gear stage, which is in contact with oil as a lubricant and for heat dissipation, and more preferably in the form of the ring gear, is lubricated by immersion lubrication such that this gear is partially immersed in an oil bath during an operating state of the e-bike drive unit. An operating state of the e-bike drive unit can be any state in which the e-bike drive unit is installed and can be operated as intended in an e-bike. For example, this can also include a state in which the e-bike drive unit is installed as intended in an e-bike but is not actively operated, and 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 upside down (for example, for storage or transport purposes).

[0034] 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(s).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.

[0035] Due to the preferred at least partial arrangement of the e-bike drive unit within the downtube, the installation position differs from that of the e-bike drive unit when, 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, the motor shaft axis of rotation and the axes of rotation of the planetary gear are preferably arranged parallel to an axis of the downtube and / or preferably assume an angle greater than 10°, in particular greater than 20°, with a horizontal plane when the e-bike is standing on a flat and horizontal surface.

[0036] 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.

[0037] 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 that allows the filler opening to 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 located in the inlet closure element. The inlet closure element may include a filler screw.

[0038] 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.

[0039] 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.

[0040] Preferably, the head of the inlet closure element extends vertically to the highest point of the housing for moving it into the closed state of the filling recess (in the assembled state).

[0041] 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.

[0042] 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.

[0043] 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.

[0044] If the distance between the air inlet opening and an adjacent inner wall of the housing is so large that, regardless of the orientation of the e-bike drive unit, the air inlet opening does not immerse itself in the oil bath forming in the housing when at rest, then a condition is met to prevent unintentional oil leakage from the gearbox interior.

[0045] 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.

[0046] 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.

[0047] Preferably, the distance of the air inlet opening to the nearest housing wall, or to the housing wall in which the pressure relief valve is arranged, is greater than 0.5 cm or 1 cm, or is adapted to the amount of oil arranged in the housing and the shape of the housing in such a way 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] In a further embodiment, a separate drain recess for filling can be dispensed with, and only one (previously described) filling recess can be provided, which filling recess can then be used for both filling and draining the lubricant.

[0053] 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, especially of the output gear stage; - a bevel gear, especially of the output gear stage; - a planetary gear, especially of the input-side gear stage; - a ring gear, in particular of the input-side gear stage; and / or - a sun gear, especially of the input-side gear stage.

[0054] 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.

[0055] 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.

[0056] The mean outer diameter of the conical pinion can range between 10 and 30 mm and is approximately 20 mm.

[0057] 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.

[0058] A bottom bracket axle can also be designed to be driven solely by muscle power, without motor assistance.

[0059] 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.

[0060] 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.

[0061] 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. Furthermore, this allows for particularly discreet integration of the e-bike drive unit into the bicycle frame.

[0062] 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.

[0063] 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.

[0064] Preferably, the axes of the down tube and the seat tube intersect in the bottom bracket area.

[0065] 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.

[0066] 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 of ​​cutouts in the downtube. 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.

[0067] 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%.

[0068] 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.

[0069] All features described in this publication can be combined with the claimed e-bike drive device and the claimed e-bike.

[0070] The present invention is explained in detail below with reference to an exemplary embodiment and the accompanying figures. These show: Fig. 1 a perspective view of an embodiment of an e-bike drive device according to the invention, Fig. 2 the e-bike drive device from Fig. 1 in a sectional view in installed position, Fig. 3 the e-bike drive device from Fig. 1 in a sectional view in the finished position, Fig. 4 a perspective view of parts of the e-bike drive system Fig. 1, Fig. 5 a representation as in Fig. 2, enlarged and with a section plane perpendicular to this in a top view with schematically drawn oil chamber sections, Fig. 6 enlarged, a perspective sectional view of the filler screw of the inlet closure element from Fig. 2, Fig. 7 schematically, an embodiment of an e-bike according to the invention, Fig. 8 a more detailed perspective view of a section from Fig. 7, and Fig. 9 a schematic representation of the downtube cross-section of the e-bike Fig. 7.

[0071] In the figures, unless otherwise stated, the same reference symbols denote the same components with the same function.

[0072] For example, a summary of the Fig. 1, Fig. 2 and Fig. As shown in Figure 5, the embodiment of the e-bike drive device 1 depicted in the figures comprises an electric motor 2, which has a motor output shaft 31 and an e-bike component 78 driven for propelling 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).

[0073] Basically, the driven e-bike component can be 78, such as the chainring 3 (see below). Fig. 7 and Fig. 8), an integral part of the e-bike drive unit 1, or alternatively, not 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. In that case, the driven e-bike component 78 is a separate component that is fundamentally independent of the e-bike drive unit 1 and can be detached. The e-bike drive unit 1 then has at least one driven connection structure for the driven e-bike component 78, which is designed 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 the e-bike component 78.The integration into the e-bike drive device 1 refers to the driven connection structure, the integrated component of which 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 example, 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 the rotationally fixed connection or attachment of the driven e-bike component 78, for example, the chainring 3, as shown in [reference]. Fig. 4 is clearly visible. 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 toothing on the outer circumference, as the 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, any preceding or subsequent descriptions of the position or relative arrangement, etc., of other components in relation to that driven e-bike component 78 can 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 installed."connected state" also means that the driven e-bike component 78 is connected to the e-bike drive device 1 (and to the driven connection structure for the driven e-bike component 78) (as, for example, in . Fig. 5 shown).

[0074] The e-bike drive device 1 also includes a reduction gear 5 for transmitting torque from the motor output shaft 31 of the electric motor 2 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 includes at least one gear 6 in contact with oil 9 as a lubricant and for heat dissipation.

[0075] 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).

[0076] The reduction gear 5 has a total oil chamber 120. The total oil chamber has 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 connecting the inlet-side oil chamber section 122 and the outlet-side oil chamber section 124. Fig. 2 and Fig. 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 in Fig. 5 each roughly and schematically illustrated by dashed rectangles.

[0077] 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.

[0078] 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 cylindrical portion of the outlet-side oil chamber section lies in a range between 10 mm and 30 mm. While maintaining the necessary clearance 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).

[0079] 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.

[0080] 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.

[0081] 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 rotationally fixed to a planet carrier 28 of the planetary gear set 15 ( Fig. 4).

[0082] 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.

[0083] Both the input gear stage 13 and the output gear stage 14 contain oil as a lubricant and for heat dissipation.

[0084] 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.

[0085] For example, in Fig. In the installation position of the e-bike drive device 1 shown in Figure 2, the filling recess 32 is arranged offset forwards from a pivot axis B of the driven e-bike component 78 (as well as the output shaft 91 of the output-side gear stage 14) in the direction of travel of the e-bike.

[0086] In a Fig. In the horizontal installation position shown in Figure 3, with the motor output shaft 31's axis of rotation A horizontally aligned, the filling recess 32 is arranged lower, viewed vertically, than the highest apex 112 of an output-side section 114 of the housing 8, which output-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 vertically to a maximum of the highest apex 112 of the housing 8.

[0087] The in Fig. The pressure relief valve 106, shown in more detail in Figure 6, is in a closed state as long as the pressure difference between the transmission 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 transmission interior 102. Each of the channels has a minimum cross-sectional area greater than 0.5 µm². 2 The pressure relief valve 106 is diaphragm-free. One of the channels is in Fig. Figure 6, although the closed state of the pressure relief valve 106 is shown there, is clarified by a dashed arrow. The pressure relief valve 106 comprises a movable closing element 128, a valve seat 130, and a helical compression spring 132. In the closed state of the pressure relief valve 106, the helical compression spring 132 presses the closing element 128 against the valve seat 130 from the inside, sealing it.

[0088] 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.

[0089] The Fig. 3 and Fig. Figure 6 shows 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.

[0090] 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.

[0091] 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.

[0092] How Fig. As also shown in Figure 3, the drain opening 34, in the horizontal position with the motor output shaft 31's axis of rotation A aligned horizontally, is positioned higher (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.

[0093] For example, the Fig. 2 and Fig. As shown in Figure 3, the filling recess 32 and the drain recess 34 are not aligned with each other with respect to their axes. The axes of the filling recess 32 and the drain recess 34 lie in a common longitudinal plane, namely the image plane. Fig. 2 and Fig. 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 drain recess 34 run vertically. The axis of symmetry of the filling recess 32 is arranged offset in the horizontal direction from the axis of symmetry of the drain recess 34.

[0094] 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 the Fig. 2 and Fig. As shown in Figure 4, 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 device 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.

[0095] The planet gears 23 and / or the ring gear 26 have plastic components or are made of plastic.

[0096] 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 axle is approximately 80 mm. The distance S of the ring gear to the axis of the bottom bracket axle is approximately 50 mm ( Fig. 3).

[0097] The in Fig. The embodiment of the e-bike 4 shown in Figure 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.

[0098] The down tube 17 provides a mounting or fastening area 146 for the e-bike drive device 1 ( Fig. 8) The bottom bracket area 140 comprises a frame area and an area of ​​the e-bike drive unit 1, as shown. Fig. Figure 8 shows an example. The part of the bottom bracket area 140 provided by the bicycle frame 16 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] How Fig. Figure 9 shows that the downtube cross-section is rectangular, but the corners are rounded, contrary to what is shown. The largest internal dimension T is less than 10 cm. Reference symbol list 1 e-bike drive unit 2 electric motors 3 chainring 4 e-bikes 5 reduction gears 6 gear 7 Housing section 8 cases 9 Oil 13 input-side gear stage 14 output gear stage 15 planetary gears 16 bicycle frames 17 Down tube 18 seat tube 23 planetary gear 24 Oil bath 25 sun wheel 26 Ring gear 27 conical pinions 28 planetary carriers 30 angle gears 31 Motor output shaft 32 Filling recess 33 Filler screw 34 Drain recess 78 powered e-bike components 80 bottom bracket axle 84 Homepage 86 Home page 88 Output shaft of the input-side gear stage 90 Input shaft of the output-side gear stage 91 Output shaft of the output-side gear stage 92 Input shaft of the bevel gear unit 94 Output shaft of the bevel gear 96 bevel gears 98 ring gear 100 Input shaft of the planetary gearbox 102 Gearbox interior 104 Inlet closure element 105 Outlet closure element 106 Pressure relief valve 112 highest point of the case 114 Output side section of the housing 116 Head of the inlet closure element 120 Total oil capacity 122 inlet-side oil room section 124 outlet-side oil storage section 126 Oil space connection section 128 locking elements 130 Valve seat 132 helical compression spring 134 Pipe section 136 Air intake opening 138 perforated sheet 140 bottom bracket area 142 Down tube area 144 Seat tube area 146 Mounting or fastening area 147 screw connections A axis of rotation of the motor output shaft B Rotation axis of the driven e-bike component D axis of the inlet-side oil chamber section E axis of the outlet-side oil chamber section F Distance of the air inlet opening to an adjacent inner wall of the housing G Direction of travel H Distance of the motor housing to the axis of the bottom bracket shaft P is the lowest point of the housing R housing stage S Distance of the ring gear to the axis of the bottom bracket shaft T largest internal dimension U axial extent of the cylindrical sub-section of the outlet-side oil chamber section

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 gear stage (13) and an output gear stage (14); wherein the reduction gear (5) has at least one gear (6) in contact with oil (9) as a lubricant and for heat dissipation, wherein the reduction gear (5) has a total oil space (120), wherein the total oil space (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), wherein the oil space connecting section (126) connects the inlet-side oil space section (122) and the outlet-side oil space section (124), and wherein the axis (D) of the inlet-side oil chamber section (122) runs approximately perpendicular to the axis (E) of the outlet-side oil chamber section (124), wherein 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 speed of the motor output shaft (31), wherein the input-side gear stage (13) is configured to first reduce the speed of the motor output shaft (31) and the output-side gear stage (14) is configured to further reduce the speed, wherein the output gear stage (14) connects to the input gear stage (13) and an output shaft (88) of the input gear stage (13) is an input shaft (90) of the output gear stage (14), wherein 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 the input side (84) of the reduction gear (5) also has grease as a lubricant and at least in the input side (84) a combined lubrication by means of the oil (9) and the grease is provided. [2] E-bike drive device (1) according to claim 1, characterized by , 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, are / is, wherein, preferably, an input shaft (92) of the bevel gear is connected in a rotationally fixed manner to a planet carrier (28) of the planetary gear (15). [3] E-bike drive device (1) according to claim 2, characterized by , that an output shaft of the bevel gear (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. [4] E-bike drive device (1) according to claim 2 or 3, characterized by , that an input shaft (100) of the planetary gear (15) is connected to the motor output shaft (31) in a rotationally fixed manner or is formed in one piece with the motor output shaft (31). [5] E-bike drive device (1) according to one of claims 1 to 4, characterized by, that a combined lubrication using oil (9) and grease is also provided in the output side (86) of the reduction gear (5). [6] E-bike drive device (1) according to one of claims 1 to 5, with a housing (8) for surrounding the e-bike drive device (1), characterized by , that The gear (6), preferably of the output gear stage (14), which is in contact with oil (9) as a lubricant and for heat dissipation, is 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). [7] E-bike drive device (1) according to one of claims 1 to 6, with a housing (8) for surrounding the e-bike drive device (1), characterized by, 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); and / or - in a horizontal installation position with the axis of rotation (A) of the motor output shaft (31) horizontally aligned, the intake is arranged lower in the vertical direction than a highest apex (112) of the housing (8); preferably, wherein a head (116) of an inlet closure element (104) extends in the vertical direction to a maximum of the highest apex (112) of the housing (8) for placing the intake recess (32) in a closed state. [8] E-bike drive device (1) according to claim 7, characterized by , that the pressure relief valve (106) comprises a movable 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) arranged, preferably 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 the air inlet opening (136) does not immerse itself in the oil bath (24) forming in the housing (8) in a stationary state, regardless of the orientation of the e-bike drive device (1). wherein, preferably, the distance (F) of the air inlet opening (136) to the adjacent inner wall of the housing is greater than 0.5 cm, more preferably greater than 0.7 cm. [9] E-bike drive device (1) according to one of claims 1 to 8, comprising a housing (8) for surrounding the e-bike drive device, characterized by, that the housing (8) has a drain recess (34) for draining the oil (9) from a / the 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. [10] E-bike drive device (1) at least according to claims 7 and 9, characterized by , that, in a horizontal installation position with the motor output shaft (31) horizontally aligned, the filling recess (32) and the drain 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. [11] E-bike drive device (1) according to one of claims 1 to 10, 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 one of the input gear stage (13); preferably wherein the planet gear (23) and / or the ring gear (26) has / has / is made of plastic or consists of / consists of plastic. [12] E-bike (4) characterized by an e-bike drive device (1) according to one of claims 1 to 11, 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).

Citation Information

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