Elektrische antriebseinrichtung fuer ein fahrrad und fahrrad damit

Abstract

The present invention proposes an electric drive device (1; 11; 21; 31) for a bicycle, comprising an arranged transmission device (4). The transmission device (4) includes at least one planetary gear set comprising at least three rotating elements (12; SR, PT, HR) arranged to rotate relative to each other. The electric drive device (1; 11; 21; 31) further includes an electric motor (5) offset relative to the transmission device (4), a drive shaft (7; 7') mounted at least on the pedal crankshaft (6) of the bicycle, a drive wheel (8) coaxially arranged with the drive shaft (7; 7') for transmitting motor power of the electric motor (5) to the drive shaft (7; 7'), a first one-way clutch element (F1), and a second one-way clutch element (F2). The first one-way clutch element (F1) and the second one-way clutch element (F2) are arranged together in an integral one-way clutch element carrier (9). The drive wheel (8) can be connected to the drive shaft (7; 7') via the first one-way clutch element (F1) and through the integrated one-way clutch element carrier (9), and one of the rotating elements (12; SR, PT, HR) of the planetary gear set of the transmission device (4) can be connected to the drive shaft (7; 7') via the second one-way clutch element (F2) and through the integrated one-way clutch element carrier (9). The other rotating element (12; SR, PT, HR) of the planetary gear set of the transmission device (4) is integrally formed with the power transmission device (7; 7'; 9) of the transmission device (4).

Description

[Technical Field]

[0001] This invention relates to an electric drive device for a bicycle. This invention also relates to a bicycle having the electric drive device. [Previous Technology]

[0002] Electric bicycles, especially electric-assisted bicycles (Pedelec) that use an electric motor and pedals for hybrid electric and muscle power propulsion, are known to us. Electric-assisted bicycles have an electric motor housed in the pedal axle housing. A transmission mechanism for transmitting torque from the electric motor and pedals to the drive shaft of the electric bicycle is also housed in the pedal axle housing. However, the installation space in the pedal axle housing of an electric bicycle is limited. [Summary of the Invention]

[0003] In its first embodiment, the present invention relates to an electric drive device for a bicycle. The drive device can be designed to transmit electrically generated driving force to the bicycle's drive shaft. Alternatively or supplementarily, the drive device can be designed to transmit driving force generated by muscle force (e.g., by rotation of the bicycle pedals) to the bicycle's drive shaft. For example, torque can be generated by the drive device, which can be transmitted to the bicycle's drive shaft to drive the bicycle. The drive device can be a hybrid design, i.e., capable of driving the bicycle using both electricity and muscle force. The bicycle can be an electric bicycle, particularly a hybrid electric-assist bicycle. Electric-assist bicycles combine the driving force of a bicycle generated by muscle force with the driving force of a bicycle generated electrically.

[0004] The electric drive unit includes a transmission mechanism arranged in the bottom bracket (Tretlager) of the bicycle. The bottom bracket may be part of the bicycle frame, on which the pedals for driving the bicycle are arranged. The housing of the bottom bracket may be designed in the form of a tube, in which the bicycle pedals are mounted. The transmission mechanism may also be mounted in this housing. In addition, a chainring may be arranged in the bottom bracket area, which may be designed to transmit the driving force generated by the drive unit to the drive shaft of the bicycle. The transmission mechanism may be designed to convert the driving force applied by the drive unit, in the form of the driving speed generated by the drive unit, into an output speed acting on the drive shaft by means of various gear shifting elements.

[0005] The transmission includes at least one planetary gear set, wherein the planetary gear set includes at least three rotating elements arranged to rotate relative to each other, these rotating elements being designed to transmit torque. The three rotating elements arranged to rotate relative to each other may be a sun gear, a planet carrier including at least one planet gear, and a ring gear of the planetary gear set. The sun gear, planet carrier, and ring gear may each be arranged on a shaft mounted to rotate. The sun gear, planet gear, and ring gear may each be designed to mesh with each other. Depending on the diameter of each gear and the relative rotational speed, torque can be transmitted between the sun gear, planet carrier, and ring gear. For example, the ring gear can be prevented from rotating, thereby fixing the ring gear. The sun gear may be coupled to the bicycle's drive shaft. The planet carrier may be coupled to the bicycle's pedal crankshaft. Since both the sun gear and ring gear mesh with the planet carrier, torque can be transmitted from the drive unit to the bicycle's drive shaft.

[0006] Furthermore, the electric drive unit includes an electric motor offset relative to the transmission and a drive shaft mounted at least on the pedal crankshaft of the bicycle. The electric motor may be designed to convert electrical energy into mechanical energy. The electric motor may be designed, for example, as a synchronous motor or an asynchronous motor. The driven shaft of the electric motor may be connected to the rotor of the electric motor, for example, in a manner that prevents relative rotation. The electric motor may be arranged, for example, with its axis parallel to the longitudinal axis of the transmission or bottom bracket. The pedal crankshaft may be a mechanical shaft mounted longitudinally along the bottom bracket. The pedal crankshaft may extend from the bottom bracket at at least one end. A pedal crank may be mounted on each of the opposite ends of the pedal crankshaft, on which a pedal for mechanically driving the bicycle may be mounted. The drive shaft may be designed as a hollow shaft, which is fixed in a mechanically responsive connection to the pedal crankshaft. The driving force generated by the pedal crank may be transmitted to the drive shaft in the form of torque through the pedal crankshaft. The drive shaft may be further mechanically responsively connected to at least one rotating element of the planetary gear set of the transmission. The drive shaft can be further mechanically connected to the driven shaft of the electric motor.

[0007] Furthermore, the electric drive device includes a drive wheel arranged coaxially with the drive shaft for transmitting motor power from the electric motor to the drive shaft. The drive wheel may be designed in the form of a gear, which may be coupled to the driven shaft of the electric motor via a traction member. The traction member may be a chain or toothed belt capable of meshing with the teeth of the gear. Alternatively, the drive wheel may be a pulley capable of connecting to the traction member by friction engagement.

[0008] Furthermore, the electric drive device includes a first one-way clutch element and a second one-way clutch element. The first one-way clutch element and the second one-way clutch element are arranged together in an integral one-way clutch element carrier. The first one-way clutch element can be designed to couple two components of the drive device according to the direction of rotation. Accordingly, the first one-way clutch element can be designed to connect the two components of the drive device in a first rotational direction in order to transmit torque. In a second rotational direction opposite to the first rotational direction, the connection between the two components can be disengaged or interrupted by the first one-way clutch element. For example, the first one-way clutch element can prevent the shaft inside the drive device from rotating in the first rotational direction. The same applies to the second one-way clutch element as described for the first one-way clutch element. Accordingly, the coupling function of the two components of the drive device related to the rotational direction can be realized by the first or second one-way clutch element. The first and second one-way clutch elements can have pawls. Alternatively, the first and second one-way clutch elements can have clamping rollers, clamping bodies, pawl rings, or winding springs. The first and second one-way clutch elements are arranged together in a one-piece one-way clutch element carrier. Accordingly, the one-way clutch element carrier is a single component, in which the first and second one-way clutch elements are each partially arranged.

[0009] The drive wheel can be connected to the drive shaft via a first one-way clutch element and through an integrated one-way clutch element carrier. Furthermore, a rotating element of the planetary gear set of the transmission can be connected to the drive shaft via a second one-way clutch element and through an integrated one-way clutch element carrier. Accordingly, the first one-way clutch element can couple the drive wheel or an electric motor connected to the drive wheel to the drive shaft according to the direction of rotation. Accordingly, the second one-way clutch element can couple a rotating element (e.g., a ring gear) of the planetary gear set of the transmission to the drive shaft according to the direction of rotation. Due to the integrated design of the one-way clutch element carrier, these two coupling functions can be achieved with a single component.

[0010] Another rotating element of the planetary gear set in the transmission is integrally formed with the power transmission device of the transmission. This other rotating element may be, for example, the sun gear, while the ring gear of the planetary gear set may be connected to the drive shaft via a second one-way clutch element and through an integrated one-way clutch element carrier. The power transmission device of the transmission may be a single power transmission component arranged within the transmission in a manner that transmits torque (e.g., rotatably). Alternatively, the power transmission device of the transmission may be multiple power transmission components arranged relative to each other in a manner that transmits torque (particularly rotatably) within the transmission.

[0011] Accordingly, in the proposed electric drive device for bicycles, the one-way clutch element carrier itself and another rotating element of the planetary gear set are integrally formed with the power transmission device of the transmission device. This saves on components. Furthermore, since fewer components need to be accommodated inside the bottom bracket, installation space inside the bottom bracket is saved. In addition, since fewer components are required, the drive device is easier to construct and has a lower construction cost.

[0012] According to one embodiment of the drive device, the power transmission device of the transmission device can be formed by a drive shaft. Accordingly, in this embodiment, one rotating element of the planetary gear set of the transmission device can be connected to the drive shaft via a second one-way clutch element and through an integrated one-way clutch element carrier. The other rotating element of the planetary gear set of the transmission device can be integrally formed with the drive shaft. In particular, this saves components, such as the teeth between the drive shaft and the rotating elements of the planetary gear set, when constructing the transmission device. Due to the integrated design, i.e., one rotating element of the planetary gear set is directly connected to the drive shaft, frictional losses generated when transmitting torque between these components can also be minimized.

[0013] According to another embodiment of the drive unit, the power transmission device of the transmission unit can be formed by an integrated one-way clutch element carrier. Accordingly, in this embodiment, the integrated one-way clutch element carrier can be integrally formed with the rotating elements of the planetary gear set. This eliminates the need for additional one-way clutch element carriers installed between the rotating elements of the planetary gear set. Therefore, the drive unit is easier to install. Furthermore, due to this design, the torque transmission function and the coupling function between the two torque transmission components can both be achieved by a single component. This reduces the complexity of the transmission unit.

[0014] According to another embodiment of the drive device, the power transmission device of the transmission device can be formed by a drive shaft and an integrated one-way clutch element carrier. In this embodiment, the above-mentioned functions and advantages can be combined.

[0015] According to another embodiment, the bicycle's drive shaft can be mechanically connected to at least one pedal crank, wherein the power transmission path can extend from the pedal crank via a transmission mechanism to the drive shaft. The pedal crank can, for example, be mounted on a pedal crank shaft. In this case, the drive shaft can be mechanically connected to the pedal crank via the pedal crank shaft on which the drive shaft is mounted. Furthermore, the drive shaft can be connected to other transmission components via a first or second one-way clutch element. Accordingly, when a manually generated driving force is applied to the pedal crank by pressing a pedal mounted on the pedal crank, this driving force can be transmitted to the drive shaft via the aforementioned functional connection.

[0016] In this embodiment, the motor power of the electric motor can be transmitted to the drive shaft at the end region of the power transmission path. The motor power of the electric motor can be transmitted to the drive shaft via a drive wheel arranged coaxially with the drive shaft. In this embodiment, the drive wheel can be arranged in a certain way inside the drive unit so that the motor power of the electric motor is transmitted to the drive shaft at the output end of the transmission unit. Accordingly, the driving force applied by the pedal crank can first be transmitted to the transmission unit via the pedal crank shaft for torque transmission, that is, setting a suitable gear ratio for the rotating elements of the planetary gear set. After setting a suitable gear ratio, that is, after shifting gears, the driving force can be enhanced by the motor power of the electric motor and applied to the drive shaft. The advantage of this design is that shifting gears can be performed without the additional motor power of the electric motor (i.e., without load). This can extend the service life of the transmission unit.

[0017] According to another embodiment, the drive wheel can be mounted on the drive shaft. The drive wheel can be directly mounted on the drive shaft. Alternatively, the drive wheel can be indirectly mounted on the drive shaft (e.g., via other rotating elements). In particular, the drive wheel can be mounted on the drive shaft in a torque-transmitting manner. The advantage of this design is that the motor power of the electric motor can be transmitted to the drive shaft particularly easily via the drive wheel.

[0018] According to one embodiment, the drive wheel can be installed in the housing of the drive device. By installing the drive wheel in the housing of the drive device, the installation space inside the drive device can be saved.

[0019] According to another embodiment, with reference to the longitudinal axis of the drive shaft, the first one-way clutch element and the second one-way clutch element can be arranged within an integral one-way clutch element carrier to be at least partially axially adjacent. The longitudinal axis of the drive shaft may, for example, correspond to the axis along which the drive shaft extends in the intermediate shaft. The first one-way clutch element and the second one-way clutch element can be arranged to be at least partially adjacent to each other along this axis. For example, the first one-way clutch element and the second one-way clutch element may contact each other on their respective outer surfaces perpendicular to the longitudinal axis of the drive shaft. Accordingly, in this embodiment, the extension of the integral one-way clutch element carrier along the longitudinal axis of the drive shaft can be greater than its extension perpendicular to this axis. In this embodiment, this saves installation space radially relative to the longitudinal axis of the drive shaft.

[0020] According to another embodiment, with reference to the longitudinal axis of the drive shaft, a first one-way clutch element and a second one-way clutch element can be arranged at least partially radially adjacent within an integrated one-way clutch element carrier. The longitudinal axis of the drive shaft may, for example, correspond to the axis along which the drive shaft extends in the intermediate shaft. The first one-way clutch element and the second one-way clutch element can be arranged to extend radially outward from this axis, at least partially adjacent. Accordingly, in this embodiment, the extension of the integrated one-way clutch element carrier perpendicular to the longitudinal axis of the drive shaft can be greater than its extension parallel to this axis. In this embodiment, this saves installation space axially relative to the longitudinal axis of the drive shaft.

[0021] According to another embodiment, with reference to the longitudinal axis of the drive shaft, the first one-way clutch element and the second one-way clutch element can be oriented in the same direction within an integral one-way clutch element carrier. The first one-way clutch element and the second one-way clutch element can be designed, for example, as first and second pawls. The first and second pawls can be oriented within the integral one-way clutch element carrier such that the pawls can extend at least partially radially outward relative to the longitudinal axis of the drive shaft. Alternatively, the first and second pawls can extend radially inward relative to the longitudinal axis of the drive shaft. Further design and related orientation of the first and second one-way clutch elements are also conceivable. The advantage of this embodiment is that the first and second one-way clutch elements can be formed particularly easily (i.e., in the same direction) within an integral one-way clutch element carrier.

[0022] According to another embodiment, with reference to the longitudinal axis of the drive shaft, the first one-way clutch element and the second one-way clutch element may be oriented in opposite directions within an integral one-way clutch element carrier. The first one-way clutch element and the second one-way clutch element may, for example, be designed as first and second pawls. The first and second pawls may be oriented within the integral one-way clutch element carrier such that the first pawl extends at least partially radially outward relative to the longitudinal axis of the drive shaft. The second pawl extends at least partially radially inward relative to the longitudinal axis of the drive shaft. Further design and related orientation of the first and second one-way clutch elements are also conceivable. An advantage of this embodiment is that the first and second one-way clutch elements can be formed particularly easily (i.e., axially mirror-reflectively) within an integral one-way clutch element carrier.

[0023] According to another embodiment, the first one-way clutch element and the second one-way clutch element can be arranged inside an integrated one-way clutch element carrier at a predetermined distance from the longitudinal axis of the drive shaft. The predetermined distance between the integrated one-way clutch element carrier and the longitudinal axis of the drive shaft can be determined or designed according to the expected load of the first one-way clutch element and the second one-way clutch element. For example, when the expected load is high, the first one-way clutch element and the second one-way clutch element can be arranged at a larger distance from the longitudinal axis of the drive shaft. Alternatively, if the expected load is low, the first one-way clutch element and the second one-way clutch element can be arranged at a smaller distance from the longitudinal axis of the drive shaft. In this way, the torque acting on the integrated one-way clutch element carrier can be adjusted by appropriately selecting the distance between the integrated one-way clutch element carrier and the longitudinal axis of the drive shaft. This can extend the service life of the integrated one-way clutch element carrier.

[0024] In the second embodiment, the present invention relates to a bicycle, including an electric drive device according to the first embodiment and two pedal cranks arranged on opposite ends of a pedal crank shaft. The pedal cranks are mechanically connected to a drive shaft fixed to the pedal crank shaft for human-powered propulsion of the bicycle. Further features, embodiments, and advantages are described in the first embodiment. Conversely, the features, embodiments, and advantages of the second embodiment also constitute the features, embodiments, and advantages of the first embodiment.

Implementation Method

[0026] Figure 1 schematically shows a portion of an electric drive unit 1, which is arranged in the bottom bracket 3 of a bicycle (not shown in Figure 1). With reference to the view shown, the drive unit 1 extends horizontally downwards in a mirror image. The electric drive unit 1 includes a transmission 4 arranged in the bottom bracket 3. The transmission 4 is shown in Figure 1 as a planetary gear transmission 4, and includes a sun gear SR, a plurality of planetary gears PR arranged on a planet carrier PT, and a ring gear HR. The planetary gear transmission 4 is designed to transmit torque in a conventional manner via the sun gear SR, the planet carrier PT, and the ring gear HR.

[0027] The drive unit 1 further includes an electric motor 5 offset relative to the transmission unit 4, the electric motor being used to electrically drive the bicycle. In the view of FIG1, the electric motor 5 is arranged such that its axis is parallel to the longitudinal axis of the transmission unit 4. Here, the electric motor 5 is offset relative to the plane of FIG1 from the transmission unit 4. A pedal crank shaft 6 is mounted in the bottom bracket 3 of the bicycle, the pedal crank shaft being mechanically connected to a pedal crank (not shown in FIG1) to drive the bicycle by muscle force. A drive shaft 7 is mounted on the pedal crank shaft 6. The drive shaft 7 is designed as a hollow shaft in the view of FIG1, the hollow shaft being mounted on the pedal crank shaft 6 by bearings L1, L2.

[0028] To electrically drive the bicycle, the electric motor 5 is mechanically connected to the drive wheel 8, which is coaxially arranged with the drive shaft 7. The torque generated by the electric motor 5 is transmitted to the drive wheel 8 via the traction member 81, which in the view of FIG1 is via the chain 81, and from the drive wheel to the drive shaft 7. The drive wheel 8 is mounted on the drive shaft 7 by ball bearing KL1.

[0029] The electric drive unit 1 further includes a first one-way clutch element F1 and a second one-way clutch element F2. The first and second one-way clutch elements F1 and F2 are shown as first and second pawls in the view of FIG1. ​​The first pawl F1 and the second pawl F2 are jointly arranged in an integral one-way clutch element carrier 9. The integral one-way clutch element carrier 9 is a single component, in which the first one-way clutch element F1 and the second one-way clutch element F2 are respectively partially arranged.

[0030] The drive wheel 8 can be connected to the drive shaft 7 via the first one-way clutch element F1, and in particular via the integrated one-way clutch element carrier 9, to transmit the motor power of the electric motor 5. In this way, the electric motor 5 can be coupled to the drive shaft 7 via the first one-way clutch element F1 and via the integrated one-way clutch element carrier 9, depending on the direction of rotation.

[0031] One of the rotating elements of the planetary gear set of the transmission device 4 can be connected to the drive shaft 7 via the second one-way clutch element F2, particularly via the integrated one-way clutch element carrier 9. In the view of FIG1, the rotating element 12 of the transmission device 4 (shown only partially) can be connected to the drive shaft 7 via the second one-way clutch element F2. Accordingly, this rotating element 12 of the transmission device 4 can be coupled to the drive shaft 7 via the second one-way clutch element F2 and via the integrated one-way clutch element carrier 9, depending on the direction of rotation.

[0032] In the embodiment shown in FIG1, further, another rotating element of the planetary gear set of the transmission device 4 is integrally formed with the power transmission devices 7 and 9 of the transmission device 4. In the view of FIG1, the power transmission devices 7 and 9 of the transmission device 4 are formed by an integral one-way clutch element carrier 9. The planet carrier PT of the planetary gear set of the transmission device 4 is integrally formed with this power transmission device 9.

[0033] The first one-way clutch element F1 and the second one-way clutch element F2 are presented as first and second pawls F1 and F2 in the integrated one-way clutch element carrier 9 shown in FIG1. ​​With reference to the longitudinal axis LA of the drive shaft 7, the first and second pawls F1 and F2 are arranged adjacent to each other in the axial direction. Furthermore, in the view of FIG1, the first and second pawls F1 and F2 are each radially outward oriented relative to the longitudinal axis LA of the drive shaft 7, i.e., oriented in the same direction. Additionally, in the view of FIG1, the first and second pawls F1 and F2 are arranged at a relatively small predetermined distance from the longitudinal axis LA of the drive shaft 7.

[0034] FIG2 schematically shows a portion of an electric drive device 11 according to another embodiment. The elements of the drive device 11 marked with the same symbols in FIG2 are equivalent to the elements of the drive device 1 in FIG1. ​​These elements will not be discussed further when describing FIG2.

[0035] The difference between the drive device 11 in Figure 2 and the drive device 1 in Figure 1 is that the ring gear HR of the planetary gear set of the transmission device 4 can be connected to the drive shaft 7 via the second one-way clutch element F2, specifically via the integrated one-way clutch element carrier 9. Similar to the drive device 1 in Figure 1, in the view of Figure 2, the power transmission devices 7 and 9 of the transmission device 4 are also formed by the integrated one-way clutch element carrier 9. Unlike the view of Figure 1, in the drive device 11 in Figure 2, the sun gear SR of the planetary gear set of the transmission device 4 is integrally formed with the integrated one-way clutch element carrier 9, rather than the planet carrier PT.

[0036] In the view of FIG2, the first one-way clutch element F1 and the second one-way clutch element F2 are also presented as first and second pawls F1 and F2. With reference to the longitudinal axis LA of the drive shaft 7, the first and second pawls F1 and F2 are arranged to be at least partially radially adjacent. Furthermore, in the view of FIG2, with reference to the longitudinal axis LA of the drive shaft 7, the first pawl F1 is radially inwardly oriented, and the second pawl F2 is radially outwardly oriented. Compared to the embodiment of FIG1, this saves axial installation space in the drive unit 11. Furthermore, in the view of FIG2, the predetermined distance between the first and second pawls F1 and F2 and the longitudinal axis LA of the drive shaft 7 is greater than the predetermined distance shown in FIG1.

[0037] FIG3a schematically shows a portion of an electric drive device 21 according to another embodiment. The elements of the drive device 21 marked with the same symbols in FIG3 are equivalent to the elements of the drive device 1 in FIG1 and the elements of the drive device 11 in FIG2. These elements will not be discussed further when describing FIG3a.

[0038] In the drive unit 21 of FIG3a, the ring gear HR of the planetary gear set of the transmission device 4 can still be connected to the drive shaft 7 via the second one-way clutch element F2, i.e., via the integrated one-way clutch element carrier 9. However, unlike the drive unit 1 of FIG1 and the drive unit 11 of FIG2, in the view of FIG3, the power transmission devices 7 and 9 of the transmission device 4 are formed by the drive shaft 7. Accordingly, in the drive unit 21 of FIG3, the sun gear SR of the planetary gear set of the transmission device 4 is integrally formed with the drive shaft 7.

[0039] In the view of FIG3a, the first one-way clutch element F1 and the second one-way clutch element F2 are also presented as first and second pawls F1 and F2. With reference to the longitudinal axis LA of the drive shaft 7, the first and second pawls F1 and F2 are at least partially axially adjacent and arranged radially inward, i.e., arranged in the same direction. Furthermore, in the view of FIG3a, the predetermined distance between the first and second pawls F1 and F2 and the longitudinal axis LA of the drive shaft 7 is greater than the predetermined distance shown in FIG1 and FIG2. This allows pawls F1 and F2 to absorb greater torque compared to drive units 1 and 11.

[0040] Figure 3b schematically illustrates an improved version of the drive unit 21 according to Figure 3a. Here, the drive shaft 7' of the drive unit 21 extends radially outward relative to the longitudinal axis LA. The advantage of this design is that the other drive wheels 8' used to transmit driving force from the drive unit 21 to the drive shaft of the bicycle can be mounted on the drive shaft with a shorter distance from the drive shaft 7'. In addition, a sealing element 10a is provided between the radially outwardly extending drive shaft 7' and the housing 10 of the drive unit 21. The housing 10 of the drive unit 21 can be sealed by the sealing element 10a to prevent dirt and / or moisture from entering.

[0041] FIG4 schematically shows a portion of an electric drive device 31 according to another embodiment. The elements of the drive device 31 marked with the same symbols in FIG4 are equivalent to the elements of the drive device 1 in FIG1, the elements of the drive device 11 in FIG2, and the elements of the drive device 21 in FIG3a and FIG3b. These elements will not be discussed further when describing FIG4.

[0042] In the drive unit 31 of FIG. 4, as in FIG. 1, the rotating element 12 (shown only partially) of the planetary gear set of the transmission unit 4 can be connected to the drive shaft 7 via the second one-way clutch element F2, particularly via the integrated one-way clutch element carrier 9. However, unlike the drive units 1, 11, and 21 of FIG. 1, 2, and 3a, in the view of FIG. 4, the power transmission devices 7 and 9 of the transmission unit 4 are formed by both the drive shaft 7 and the integrated one-way clutch element carrier 9. In the view of FIG. 4, the sun gear SR of the planetary gear set of the transmission unit 4 is integrally formed with these power transmission devices 7 and 9. Accordingly, in the drive unit 31 of FIG. 4, the sun gear SR of the planetary gear set of the transmission unit 4, the drive shaft 7, and the integrated one-way clutch element carrier 9 are all integrally formed. This makes the drive unit 31 particularly easy to construct, as fewer parts are required compared to constructing the drive units 1, 11, and 21.

[0043] Furthermore, in the drive unit 31 of FIG. 4, the drive wheel 8 is mounted in the housing 10 of the drive unit 31. In this way, with reference to the longitudinal axis LA of the drive shaft 7, the integrated one-way clutch element carrier 9 can be arranged radially inward relative to the ball bearing KL1 of the drive wheel 8. Therefore, the one-way clutch element carrier 9 and the ball bearing KL1 can be arranged radially stacked. With reference to the longitudinal axis LA of the drive shaft 7, axial installation space can be saved. [Simplified Explanation of the Diagram]

[0025] [Figure 1] is a schematic diagram of a portion of an electric drive device according to one embodiment of the present invention, the electric drive device being arranged in the bottom bracket of a bicycle. [Figure 2] is a schematic diagram of a portion of an electric drive device according to another embodiment of the present invention, the electric drive device being arranged in the bottom bracket of a bicycle. [Figure 3a] is a schematic diagram of a portion of an electric drive device according to another embodiment of the present invention, the electric drive device being arranged in the bottom bracket of a bicycle. [Figure 3b] is a schematic diagram of a portion of an electric drive device according to an improved embodiment of FIG. 3a, the electric drive device being arranged in the bottom bracket of a bicycle. [Figure 4] is a schematic diagram of a portion of an electric drive device according to another embodiment of the present invention, the electric drive device being arranged in the bottom bracket of a bicycle.

Claims

1. An electric drive device (1; 11; 21; 31) for a bicycle, comprising: A transmission device (4) arranged in the central shaft (3) of the bicycle, the transmission device including at least one planetary gear set, wherein the planetary gear set includes at least three rotating elements (12; SR, PT, HR) arranged to rotate relative to each other, the rotating elements being designed to transmit torque; an electric motor (5) offset relative to the transmission device (4); a drive shaft (7; 7') mounted at least on the pedal crankshaft (6) of the bicycle; a drive wheel (8) coaxially arranged with the drive shaft (7; 7') for transmitting motor power from the electric motor (5) to the drive shaft (7; 7'); a first one-way clutch element (F1); and a second one-way clutch element (F2), wherein the first one-way clutch element (F1) and the second one-way clutch element (F2) are arranged together in an integral one-way clutch element carrier (9), wherein the drive wheel (8) can be connected to the drive shaft (7; 7') via the first one-way clutch element (F1) and through the integral one-way clutch element carrier (9), One of the rotating elements (12; SR, PT, HR) of the planetary gear set of the transmission device (4) can be connected to the drive shaft (7; 7') via the second one-way clutch element (F2) and through the integrated one-way clutch element carrier (9), and the other of the rotating elements (12; SR, PT, HR) of the planetary gear set of the transmission device (4) is integrally formed with the power transmission device (7; 7'; 9) of the transmission device (4).

2. The electric drive device (1; 11; 21; 31) of claim 1, wherein the power transmission device (7; 7'; 9) of the transmission device (4) is formed by the drive shaft (7; 7').

3. The electric drive device (1; 11; 21; 31) of claim 1, wherein the power transmission device (7; 7'; 9) of the transmission device (4) is formed by the integrated one-way clutch element carrier (9).

4. The electric drive device (1; 11; 21; 31) of claim 1, wherein the power transmission device (7; 7'; 9) of the transmission device (4) is formed by the drive shaft (7; 7') and the integrated one-way clutch element carrier (9).

5. An electric drive device (1; 11; 21; 31) of any one of claims 1 to 4, wherein the drive shaft (7; 7') of the bicycle is mechanically and activatingly connected to at least one pedal crank (62), wherein the power transmission path is from the pedal crank (62) through the transmission device (4) to the drive shaft (7; 7').

6. The electric drive device (1; 11; 21; 31) of claim 5, wherein the motor power of the electric motor (5) is transmitted to the drive shaft (7; 7') in the end region of the power transmission path.

7. The electric drive device (1; 11; 21) of claim 1, wherein the drive wheel (8) is mounted on the drive shaft (7; 7').

8. The electric drive device (31) of claim 1, wherein the drive wheel (8) is mounted in the housing (10) of the electric drive device (31).

9. The electric drive device (1; 21; 31) of claim 1, wherein, with reference to the longitudinal axis (LA) of the drive shaft (7; 7'), the first one-way clutch element (F1) and the second one-way clutch element (F2) are arranged to be at least partially axially adjacent within the integral one-way clutch element carrier (9).

10. The electric drive device (11) of claim 1, wherein, with reference to the longitudinal axis (LA) of the drive shaft (7; 7'), the first one-way clutch element (F1) and the second one-way clutch element (F2) are arranged to be at least partially radially adjacent within the integral one-way clutch element carrier (9).

11. The electric drive device (1; 21; 31) of claim 1, wherein, with reference to the longitudinal axis (LA) of the drive shaft (7; 7'), the first one-way clutch element (F1) and the second one-way clutch element (F2) are oriented in the same direction inside the integral one-way clutch element carrier (9).

12. The electric drive device (11) of claim 1, wherein, with reference to the longitudinal axis (LA) of the drive shaft (7; 7'), the first one-way clutch element (F1) and the second one-way clutch element (F2) are oriented in opposite directions inside the integral one-way clutch element carrier (9).

13. The electric drive device (1; 11; 21; 31) of claim 1, wherein the first one-way clutch element (F1) and the second one-way clutch element (F2) are arranged inside the integral one-way clutch element carrier (9) at a predetermined distance from the longitudinal axis (LA) of the drive shaft (7; 7').

14. A bicycle comprising an electric drive device (1; 11; 21; 31) as claimed in any one of claims 1 to 13 and two pedal cranks (62) disposed at opposite ends of the pedal crank shaft (6), wherein the pedal cranks (62) are mechanically operably connected to the drive shaft (7; 7') fixed to the pedal crank shaft (6) for human-powered operation of the bicycle.

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