Drive unit for a vehicle which can be operated by muscle power

The drive unit for muscle-powered vehicles achieves compactness and longevity through a coaxial alignment and bearing arrangement, along with a planetary gear system and sealing elements, addressing the challenges of existing designs.

WO2025210005A1PCT designated stage Publication Date: 2025-10-09ZF FRIEDRICHSHAFEN AG
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Patent Information

Application Number
PCT/EP2025/058797
Authority / Receiving Office
WO · WO
Patent Type
Applications
Current Assignee / Owner
Priority Date
2024-04-03
Filing Date
2025-04-01
Publication Date
2025-10-09

AI Technical Summary

Technical Problem

Existing drive units for muscle-powered vehicles, such as e-bikes, face challenges in achieving a compact design and a long service life.

Method used

The drive unit incorporates a design with an input element, a stationary component, and an output element, featuring a coaxial alignment and specific bearing arrangements to ensure stability and compactness, along with a planetary gear system and sealing elements to enhance durability.

Benefits of technology

This design results in a compact and durable drive unit with improved service life, suitable for muscle-powered vehicles like bicycles and e-bikes.

✦ Generated by Eureka AI based on patent content.

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    Figure EP2025058797_09102025_PF_FP_ABST
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Abstract

A drive unit for a vehicle which can be operated by muscle power has an input element (4), a stationary component (9), an output transmission (30) and an output element (5). The input element (4) extends through the output element (5) in the axial direction, is coaxial with respect to the output element (5) and is mechanically operatively connected to the output element (5) via the output transmission (30) in order to output a drive force. The output element (5) is mounted on the stationary component (9) via a first output bearing (61) and via a second output bearing (62), and the outer circumference of the first output bearing (61) is smaller than the outer circumference of the second output bearing (62).
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Description

[0001] Drive unit for a muscle-powered vehicle and vehicle

[0002] The present invention relates to a drive unit for a muscle-powered vehicle and a vehicle having a drive unit.

[0003] A drive unit for a human-powered vehicle, such as an e-bike, is known. Such a drive unit may include an electric motor to support a mechanical drive to propel the vehicle. The electric motor and the mechanical drive may drive a summing gear arranged within a drive housing. Drive force may be transmitted via an output shaft from the summing gear to a sprocket arranged outside the drive housing. A long service life of the drive unit is of great importance for vehicles.

[0004] The object of the present invention is to provide an improved drive unit that is compact and has an improved service life. The present invention achieves this object with the features described herein. Advantageous further developments are the subject of the dependent claims.

[0005] In a first aspect, a drive unit for a vehicle operable with muscle power is provided. The vehicle can be formed by a bicycle, an e-bike, or a pedelec. The drive unit has an input element, a stationary component, an output gear, and an output element. The input element can be formed by a pedal crank. The input element can have pedals. The stationary component can have at least one of a gear housing and a housing cover. The output gear can have a summing gear, for example a planetary gear. The output element can be designed in two parts. The output element can have at least one of a sprocket, a belt pulley, or a spur gear. The output element can have an output shaft.

[0006] The input element extends in an axial direction through the output element. The input element can have an axis of rotation. The axis of rotation can be aligned in the axial direction. A radial direction can be aligned substantially perpendicular to the axial direction. The input element is arranged coaxially to the output element. The input element is mechanically operatively connected to the output element via the output gear for outputting a drive force. The output element is rotatably mounted on the stationary component via a first output bearing and a second output bearing. The input element is rotatably mounted on the output element via an input bearing. The input element can be mounted in the output element.An outer circumference of the first output bearing is smaller than an outer circumference of the second output bearing. The first output bearing can be arranged radially and axially within the second output bearing. This ensures that the output element is stably mounted on the stationary component, and the drive unit can be designed compactly.

[0007] If two elements are mechanically operatively connected, they are directly or indirectly coupled to one another in such a way that a movement of one element causes a reaction in the other element. For example, a mechanical operative connection can be provided by a positive or frictional connection. The mechanical operative connection can correspond to the meshing of corresponding teeth of the two elements. Additional elements, such as one or more spur gear stages, can be provided between the elements. A permanently rotationally fixed connection between two elements, on the other hand, is understood to be a connection in which the two elements are rigidly coupled to one another in all intended states of the transmission. The elements can be present as individual components that are rotationally connected to one another or as a single piece.

[0008] The input element can be mounted on the stationary component via a first input bearing. The input element can be mounted on the output element via a second input bearing. The output element is then rotatably mounted on the input element via the second input bearing. The first input bearing can be arranged on a first side of the stationary component. The second input bearing can be arranged on a second side of the stationary component. The first side can be arranged opposite the second side with respect to the output gear. The second side can be a side of the drive unit on which the output element is arranged. The first input bearing can be formed by a radial bearing, for example a needle bearing. The second input bearing can be formed by a radial bearing, for example a ball bearing such as a deep groove ball bearing.The second input bearing may be arranged radially within the first output bearing. The second input bearing may be arranged axially in the same plane as the first output bearing.

[0009] The output shaft can be connected to the sprocket or the pulley in a rotationally fixed manner. The output element can extend in a U-shape in the radial direction. The output element can extend in the radial direction on both sides along a wall section of the stationary component, for example, the housing cover. The output element can be rotationally connected to an output element of the output gear. The output element can be rotationally connected to a ring gear of the output gear. The output element can form the ring gear of the output gear. The output shaft can form the ring gear on an inner circumference.

[0010] The stationary component may have a bearing seat for receiving the first output bearing. The stationary component may have a bearing seat for receiving the second output bearing. At least one of the bearing seat for the first output bearing and the bearing seat for the second output bearing may be formed on an inner circumference of the stationary component. At least one of the bearing seat for the first output bearing and the bearing seat for the second output bearing may be formed in the housing cover. For example, the bearing seat for the first output bearing may be formed in the housing cover. For example, both the bearing seat for the first output bearing and the bearing seat for the second output bearing may be formed in the housing cover. Both the first output bearing and the second output bearing may be arranged on the second side of the stationary component.The drive unit can therefore be designed such that the first output bearing and the second output bearing are not arranged on opposite sides of the stationary component. As a result, a bearing arrangement for the output element in the axial direction can be designed to be compact. At least one of the first output bearing and the second output bearing can be formed by a rolling bearing, for example a ball bearing, a tapered roller bearing, or a needle bearing. For example, both the first output bearing and the second output bearing can be formed by a ball bearing. At least one of the first output bearing and the second output bearing can be formed by a radial bearing. Both the first output bearing and the second output bearing can be formed by a radial bearing.

[0011] In one embodiment of the drive unit, the second output bearing can be arranged radially outside the output gear, axially at least partially in the same plane as the output gear, and axially offset from the first output bearing. The second output bearing can be arranged axially in the same plane as the ring gear of the output gear. The second output bearing can be arranged radially outside the output element, for example the ring gear, of the output gear. The bearing seat for the first output bearing and the bearing seat for the second output bearing can each be formed on an inner circumference of the stationary component.

[0012] In one embodiment of the drive unit, the second output bearing can be formed by a needle bearing. The second output bearing can have an outer ring. The outer ring can be fastened to the bearing seat of the stationary component. The stationary component can then be made of a lightweight material, for example, aluminum. The outer ring can be pressed onto the bearing seat for the second output bearing. The outer ring can be secured in the axial direction by a securing element, for example, a retaining ring or a snap ring. Rolling elements of the first output bearing can be in contact with an outer periphery of the output element.

[0013] In one embodiment of the drive unit, the second output bearing can be arranged offset in the axial direction from the output gear and in the axial direction in the same plane as the first output bearing. The bearing seat of the stationary component for the first output bearing can be formed on an inner circumference of the stationary component, for example the housing cover. The bearing seat of the stationary component for the second output bearing can be formed on an outer circumference of the stationary component, for example the housing cover. The bearing seat of the output element for the second output bearing can be formed on an inner circumference of the output element.

[0014] In one embodiment of the drive unit, the second output bearing can be formed by a deep groove ball bearing. The drive unit can then be designed to be compact in both the axial and radial directions.

[0015] In one embodiment of the drive unit, the output gear can be arranged radially within the output element. The output gear can be arranged axially at least partially within the output element. The output element can extend radially along the output gear. The output element can extend radially beyond the output gear. The output element can cover an outer circumference of the output gear in the axial direction, at least partially.

[0016] In one embodiment of the drive unit, the drive unit can have a first electric motor with a first rotor. The output transmission can have a planetary gear set with a first gear set element, a second gear set element, and a third gear set element. The first rotor can be mechanically operatively connected to the first gear set element for inputting a drive force. The input element can be rotationally connected to the second gear set element. The input element can be rotationally connected to the second gear set element in at least one direction of rotation. The input element can be rotationally connected to the second gear set element via a freewheel in a first direction of rotation and rotatable in a second direction of rotation opposite to the first direction of rotation. The third gear set element can be rotationally connected to the output element for outputting a drive force.The first rotor can be mechanically operatively connected to the first gear set element of the output transmission via a first gear set. The first rotor can be mechanically operatively connected to the first gear set element of the output transmission via a second gear set. At least one of the first gear set and the second gear set can be formed by a planetary gear set. The first rotor can be mechanically operatively connected to the first gear set element of the output transmission via at least one of a first planetary gear set and a second planetary gear set.

[0017] The first planetary gear set may include a first sun gear, a first planet carrier, one or more first planet pinions, one or more first planet gears, and a first ring gear. The second planetary gear set may include a second sun gear, a second planet carrier, one or more second planet pinions, one or more second planet gears, and a second ring gear.

[0018] The rotor can be connected to the first sun gear in a rotationally fixed manner. The first planetary gear set can be arranged radially within the second planetary gear set. The first planetary gear set and the second planetary gear set can be arranged in the same plane in the axial direction. The second planetary gear set can be arranged offset from the first planetary gear set in the axial direction.

[0019] The first sun gear can mesh with the first planet gear. The first planet gear can be mounted on the first planet pin via a bearing, for example a radial bearing, a deep groove ball bearing, a plain bearing, or a needle bearing. The first planet pin can be attached to the first planet carrier, for example, pressed into the first planet carrier. The first planet gear can mesh with the first ring gear. The first ring gear can be connected in a rotationally fixed manner to the second sun gear. A sun ring gear can form the first ring gear on an inner circumference and the second sun gear on an outer circumference.

[0020] The second sun gear can mesh with the second planet gear. The second planet gear can be mounted on the second planet pin via a bearing, for example a radial bearing, a deep groove ball bearing, a plain bearing or a needle bearing. The second planet pin can be attached to the second planet carrier, for example pressed into the second planet carrier. The second planet carrier can be attached to the stationary component. The second planet carrier can be formed by the stationary component. The second planet gear can mesh with the second ring gear. The second ring gear and the first planet carrier can be connected in a rotationally fixed manner to an output shaft. As a result, the first ring gear can be connected in a rotationally fixed manner to the first planet carrier.

[0021] The output transmission with the third planetary gear set can have at least a third sun gear, a third planet carrier, and a third ring gear. The third planetary gear set can further have one or more third planetary pinions and one or more third planetary gears. The third sun gear can mesh with the third planetary gear. The third planetary gear can be rotatably mounted on the third planetary pinion via a bearing, for example a radial bearing, a deep groove ball bearing, a plain bearing, or a needle bearing. The third planetary pinion can be attached to the third planetary carrier, for example, pressed into the third planetary carrier. The third planetary gear can mesh with the third ring gear.

[0022] The first gear set element can be formed by the third sun gear. The output shaft can be connected in a rotationally fixed manner to the third sun gear. The output shaft can form the third sun gear on an outer circumference. The second gear set element can be formed by the third planet carrier. The third planet carrier can be connected in a rotationally fixed manner to the output element. The third gear set element can be formed by the third ring gear. The third ring gear can be connected in a rotationally fixed manner to the output element.

[0023] At least one of the first electric motor, the first planetary gear set, and the second planetary gear set can be arranged in the axial direction on the first side of the output transmission. Power electronics for operating the first electric motor can be arranged coaxially with the output element on the first side of the output transmission. The power electronics can be arranged on the first side of the first planetary gear set and the second planetary gear set.

[0024] In one embodiment of the drive unit, one of the first gear set element, the second gear set element, and the third gear set element of the output transmission can be rotatably mounted on the output element via a third output bearing. For example, the third planet carrier can be rotatably mounted on the output element. The third planet carrier can be rotatably mounted on the third ring gear. The third output bearing can be designed as a radial bearing. The third output bearing can be formed by a ball bearing, for example a deep groove ball bearing. The output element can have a bearing seat for the third output bearing on an inner circumference. The third output bearing can be arranged offset in the axial direction with respect to the first output bearing towards the first side. An outer circumference of the third output bearing can be smaller than an inner circumference of the second output bearing.The outer circumference of the third output bearing may be smaller than an outer circumference of the first output bearing.

[0025] In one embodiment of the drive unit, a first sealing element, a second sealing element and a third sealing element can be arranged on the output element for sealing an inner side of the stationary component from an outer side of the stationary component.

[0026] The second input bearing can be sealed to an outside of the drive unit by the first sealing element, for example a radial shaft seal. The first sealing element can be offset in the axial direction and arranged adjacent to the second input bearing. The first sealing element can be positioned on a bearing seat for the second input bearing. The first sealing element can be attached to an inner circumference of the output element. A cylindrical portion of the input element extending in the axial direction can be in sliding contact with a sealing lip of the first sealing element.

[0027] The first output bearing can be sealed to an outer side of the drive unit via the second sealing element, for example a radial shaft seal. The second sealing element can be offset in the axial direction and arranged adjacent to the first output bearing. The second sealing element can be positioned on the bearing seat for the first output bearing. The second sealing element can be fastened to an inner circumference of the stationary component. A projection of the output element, for example the chain wheel, projecting in the axial direction or a cylindrical surface extending in the axial direction can be in sliding contact with a sealing lip of the second sealing element. A third sealing element, for example an O-ring, can be arranged on an inner circumference of the chain wheel or pulley and on an outer circumference of the output shaft for sealing an inner side of the stationary component from an outer side.

[0028] In one embodiment of the drive unit, the drive unit can have a second electric motor with a second rotor. The second rotor can be mechanically connected to the output element via a transmission gear for outputting a drive force. The output element can have a toothing, for example an external toothing, for the mechanical operative connection with the second rotor. The external toothing can be formed by a spur gear or a chain gear. The external toothing can be in engagement with a toothing of the transmission gear. The external toothing can be arranged outside the bearing seat of the output element for the second output bearing. The second output bearing can be arranged in the same plane as the external toothing in the axial direction. The second output bearing can be arranged offset from the external toothing in the axial direction.The second output bearing can be arranged adjacent to or next to the external gearing in the axial direction.

[0029] In one aspect, a vehicle has at least one drive wheel and a drive unit according to one of the preceding embodiments. The vehicle can be operated using muscle power. The vehicle can be a bicycle, an e-bike, or a pedelec. The drive wheel is mechanically operatively connected to the drive unit via the output element such that the drive unit can propel the vehicle. The vehicle can have other devices such as a braking device or a steering device.

[0030] Figure 1 shows a sectional view of an embodiment of a drive unit.

[0031] Figure 2 shows a sectional view of another embodiment of the drive unit.

[0032] Figure 3 shows a sectional view of another embodiment of the drive unit. Figure 4 shows a sectional view of another embodiment of the drive unit.

[0033] Figure 1 shows a sectional view of one embodiment of a drive unit. The drive unit can be used for a vehicle that can be operated using muscle power, in this case an e-bike. The drive unit has an input element 4, in this case a pedal crankshaft, a stationary component 9, in this case a gear housing with a housing cover, an output gear 30, and an output element 5. The drive unit further has a first electric motor 70, which is arranged coaxially to the output element 5 and is mechanically operatively connected to the output element 5 via the output gear 30 for outputting a drive force. The input element 4 extends in an axial direction through the output element 5 coaxially to the output element 5. The input element 4 is mechanically operatively connected to the output element 5 via the output gear 30 for outputting a drive force.

[0034] The output element 5 is mounted on the stationary component 9 via a first output bearing 61 and a second output bearing 62. The transmission housing has a bearing seat for the first output bearing 61 on an inner circumference. The housing cover has a bearing seat for the second output bearing 62 on an inner circumference. The output element 5 is rotatably mounted on the input element 4 via an input bearing 42, in this case a second input bearing 42. As a result, the output element 5 is stably mounted in the stationary component 9, which leads to a long service life of the drive unit. An outer circumference of the first output bearing 61 is smaller than an outer circumference of the second output bearing 62.

[0035] Further details of the drive unit are described below.

[0036] The output element 5 here comprises a chain wheel and an output shaft. The output shaft has bearing seats for the first output bearing 61 and the second output bearing 62. The bearing seat for the first output bearing 61 is arranged on an outer circumference of the output shaft. The bearing seat for the second output bearing 62 is also arranged on an outer circumference of the output shaft. The second output bearing 62 is arranged offset in the axial direction relative to the first output bearing 61 toward the first side. The second output bearing 62 is arranged outside the output gear 30 in the radial direction and is arranged in the same plane as the output gear 30 in the axial direction.

[0037] The sprocket is connected to the output shaft in a rotationally fixed manner. The output shaft extends from the first side, the left side in Figure 1, through a wall section of the housing cover of the stationary component 9 to an outer side of the stationary component 9 on the second side, the right side in Figure 1. The wall section of the stationary component 9 is arranged on the second side of the stationary component 9. The output shaft extends on the first side relative to the stationary component 9, i.e. an inner side of the stationary component 9, in the radial direction outwards along the wall section. The sprocket extends from the output shaft in the radial direction outwards along the wall section. The output element 5 thus forms a U-shaped cross-section that extends along a section of the wall section of the stationary component 9.

[0038] The input element 4 is rotatably mounted in the stationary component 9 on the first side relative to the stationary component 9 via a first input bearing 41, in this case a needle bearing. The input element 4 is rotatably mounted on the output element 5 on the second side relative to the stationary component 9 via the second input bearing 42, in this case a deep groove ball bearing. As a result, the input element 4 is mounted on opposite sides of the stationary component 9. The first input bearing 41 is arranged in the axial direction and in the radial direction within the first electric motor 70. The second input bearing 42 is arranged in the radial direction within the first output bearing 61. The second input bearing 42 is arranged in the axial direction in the same plane as the first output bearing 61. An outer circumference of the second input bearing 42 is smaller than an inner circumference of the first output bearing 61.

[0039] A first sealing element 91, in this case a radial shaft seal, is arranged adjacent to the second input bearing 42 in the axial direction and offset towards the second side. The first sealing element 91 is fastened to an inner circumference of the output shaft. A cylindrical section of the input element 4 extending in the axial direction is in sliding contact with a sealing lip of the first sealing element 91. A second sealing element 92 is arranged adjacent to the first output bearing 61 and offset in the axial direction towards the second side. The second sealing element 92 is fastened to an inner circumference of the wall section. An outer surface of a projection of the sprocket projecting in the axial direction towards the first side is in sliding contact with a sealing lip of the second sealing element 92. A third sealing element 93, in this case an O-ring, rests against an inner circumference of the sprocket and against an outer circumference of the output shaft.The first sealing element 91, the second sealing element 92 and the third sealing element 93 fluidically seal the inside of the stationary component 9 from the outside of the stationary component 9.

[0040] Figure 2 shows a sectional view of a further embodiment of the drive unit. The present embodiment differs from the previous embodiment essentially in the design of the output gear 30. The output gear 30 is arranged on the second side relative to the first electric motor 70. Furthermore, the drive unit of the present embodiment has a first planetary gear set 10 and a second planetary gear set 20, which are arranged in the axial direction between the first electric motor 70 and the output gear 30. The output gear 30 is formed by a third planetary gear set and has a third sun gear 31, a third planet carrier 32, a number of third planet pins 33, a number of third planet gears 34 and a third ring gear 35.

[0041] The third sun gear 31 is mechanically connected to the first planetary gear set 10 and the second planetary gear set 20. The third sun gear 31 meshes with the third planet gears 34. The third planet gears 34 are each mounted on one of the third planetary pins 33 via a needle bearing. The third planetary pins 33 are fastened to the third planet carrier 32. The third planet carrier 32 is connected in a rotationally fixed manner to the input element 4. The third planet gears 34 mesh with the third ring gear 35. The third ring gear 35 is connected in a rotationally fixed manner to the output shaft of the output element 5. The third ring gear 35 is formed on an inner circumference of the output shaft. The second output bearing 62 is arranged radially outside the third ring gear 35 and axially in the same plane as the third ring gear 35. Figure 3 shows a sectional view of another embodiment of the drive unit.The present embodiment has all the features of at least one of the preceding embodiments. The present drive unit has a second electric motor 80 and a transmission gear 37. The first electric motor 70 has a first rotor 71 and a first stator 72. The second electric motor 80 has a second rotor 81 and a second stator 82.

[0042] The first planetary gear set 10 has a first sun gear 11, a first planet carrier 12, a number of first planetary pinions 13, a number of first planetary gears 14, and a first ring gear 15. The second planetary gear set 20 has a second sun gear 21, a second planet carrier 22, a number of second planetary pinions 23, a number of second planetary gears 24, and a second ring gear 25. The second planetary gear set 20 is arranged outside the first planetary gear set 10 in the radial direction. The second planetary gear set 20 and the first planetary gear set 10 are arranged in the same plane in the axial direction. As a result, the first planetary gear set 10 and the second planetary gear set 20 form a nested gear set.

[0043] The first sun gear 11 is rotationally connected to the first rotor 71. The first sun gear 11 meshes with the first planet gears 14. Each of the first planet gears 14 is mounted on one of the first planetary pins 13 via a bearing, in this case a needle bearing. The first planetary pins 13 are fastened to the first planet carrier 12. The first planet gears 14 mesh with the first ring gear 15. A sun ring gear forms the first ring gear 15 on an inner circumference and the second sun gear 21 on an outer circumference. As a result, the first ring gear 15 is rotationally connected to the second sun gear 21.

[0044] The second sun gear 21 meshes with the second planet gears 24. Each of the second planet gears 24 is mounted on one of the second planetary pins 23 via a bearing, in this case a needle bearing. The second planetary pins 23 are fastened to the second planet carrier 22. The second planet gears 24 mesh with the second ring gear 25. The second ring gear 25 and the first planetary carrier 12 are connected in a rotationally fixed manner to an output shaft 7. As a result, the second ring gear 25 is rotationally connected to the first planetary carrier 12. The first output shaft 7 is rotationally connected to the third sun gear 31.

[0045] The second planet carrier 22 is formed by the stationary component 9. The sun gear can abut on the second planet carrier 22 in the axial direction on a first side and is thereby limited in its movement in the axial direction.

[0046] The second electric motor 80 is arranged axially parallel to the first electric motor 70. The second electric motor 80 is operatively connected mechanically to the output shaft of the output element 5 via the transmission gear 37. For this purpose, the output shaft of the output element 5 has a toothing 36 on an outer circumference. The toothing 36 is arranged offset in the axial direction from the second output bearing 62. The toothing 36 is arranged in the axial direction in the same plane as the second input bearing 42. An outer diameter of the toothing 36 is smaller than an outer diameter of the second output bearing 62.

[0047] Figure 4 shows a further sectional view of an embodiment of the drive unit. The present embodiment differs from the previous embodiment primarily in the design of the second output bearing 62 and the output element 5.

[0048] In this case, the second output bearing 62 is designed as a deep groove ball bearing. The second output bearing 62 is arranged offset in the axial direction to the second side with respect to the output gear 30. An outer diameter of the second output bearing 62 is smaller than an outer diameter of the third ring gear 35. The second output bearing 62 is arranged in the same plane as the first output bearing 61 in the axial direction. The housing cover of the stationary component 9 forms the bearing seat for the second output bearing 62 on an outer circumference.

[0049] The output shaft of the output element 5 forms the bearing seat for the second output bearing 62 on an inner circumference. The toothing 36 and the second output bearing 62 are arranged in the same plane in the axial direction. The toothing 36 is arranged in the axial direction in a region of the bearing seat for the second output bearing 62 and in the radial direction outside the bearing seat for the second output bearing 62. In the present embodiment, the drive unit does not have the third output bearing 63. The first, second, and third sealing elements 91, 92, 93 are not shown.

[0050] Reference symbol

[0051] 4 Input element

[0052] 5 Output element

[0053] 7 Output shaft

[0054] 9 Stationary component

[0055] 10 First planetary gear set

[0056] 11 First sun gear

[0057] 12 First planet carrier

[0058] 13 First planetary bolt

[0059] 14 First planetary gear

[0060] 15 First ring gear

[0061] 20 Second planetary gear set

[0062] 21 Second sun gear

[0063] 22 Second planet carrier

[0064] 23 Second planetary bolt

[0065] 24 Second planetary gear

[0066] 25 Second ring gear

[0067] 30 output gears

[0068] 31 Third sun gear

[0069] 32 Third planet carrier

[0070] 33 Third planetary bolt

[0071] 34 Third planetary gear

[0072] 35 Third ring gear

[0073] 36 Gearing

[0074] 37 transmission gears

[0075] 41 First Entrance Camp

[0076] 42 Second input bearing 61 First output bearing

[0077] 62 Second output bearing

[0078] 63 Third output bearing

[0079] 70 First electric motor

[0080] 71 First rotor

[0081] 72 First stator

[0082] 80 Second electric motor

[0083] 81 Second rotor

[0084] 82 Second stator

[0085] 91 First sealing element

[0086] 92 Second sealing element

[0087] 93 Third sealing element

Claims

Patent claims 1. Drive unit for a vehicle that can be driven by muscle power, the drive unit comprising an input element (4), a stationary component (9), an output gear (30) and an output element (5), wherein - the input element (4) extends in an axial direction through the output element (5), is arranged coaxially to the output element (5) and is mechanically operatively connected to the output element (5) via the output gear (30) for outputting a drive force, - the output element (5) is rotatably mounted on the stationary component (9) via a first output bearing (61) and a second output bearing (62), - the input element (4) is rotatably mounted on the output element (5) via an input bearing (42), and - an outer circumference of the first output bearing (61) is smaller than an outer circumference of the second output bearing (62).

2. Drive unit according to claim 1, characterized in that the second output bearing (62) is arranged in the radial direction outside the output gear (30), in the axial direction at least partially in the same plane as the output gear (30) and in the axial direction offset from the first output bearing (61).

3. Drive unit according to claim 2, characterized in that the second output bearing (62) is formed by a needle bearing.

4. Drive unit according to claim 1, characterized in that the second output bearing (62) is arranged offset in the axial direction to the output gear (30) and in the axial direction in the same plane as the first output bearing (61).

5. Drive unit according to claim 4, characterized in that the second output bearing (62) is formed by a deep groove ball bearing.

6. Drive unit according to one of the preceding claims, characterized in that the output gear (30) is arranged in the radial direction within the output element (5).

7. Drive unit according to one of the preceding claims, characterized in that - the drive unit comprises a first electric motor (70) with a first rotor (71), - the output transmission (30) comprises a planetary gear set with a first gear set element, a second gear set element and a third gear set element, - the first rotor (71) is mechanically connected to the first wheel set element for inputting a driving force, - the input element (4) is connected to the second wheel set element in at least one direction of rotation, and - the third wheel set element is connected to the output element (5) in order to output a driving force.

8. Drive unit according to claim 7, characterized in that one of the first gear set element, the second gear set element and the third gear set element of the output transmission (30) is rotatably mounted on the output element (5) via a third output bearing (63).

9. Drive unit according to one of the preceding claims, characterized in that a first sealing element (91), a second sealing element (92) and a third sealing element (93) for sealing an inner side of the stationary component (9) against an outer side of the stationary component (9) are arranged on the output element (5).

10. Drive unit according to one of the preceding claims, characterized in that the drive unit has a second electric motor (80) with a second rotor (82) which is mechanically operatively connected to the output element (5) via a transmission gear (37) for outputting a drive force.

11. Vehicle with at least one drive wheel and a drive unit according to claims 1 to 10, wherein - the vehicle can be operated using muscle power, and - the drive wheel is mechanically connected to the drive unit via the output element (5) in such a way that the drive unit can move the vehicle.

Citation Information

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