Drive device for driving a bicycle with electronics

Abstract

A drive device (2) for driving a bicycle, comprising a drive motor (20) operatively connected to a transmission, and a traction mechanism carrier (4) for a traction mechanism transmission, and electronics comprising a torque sensor (52) and a speed sensor (51), and a control device integrated into the electronics for controlling the drive motor (20), wherein the electronics are formed from at least one electronic module (5), wherein the drive motor (20) has an output shaft (20) designed as a hollow shaft, which is arranged coaxially with a bottom bracket crankshaft (33), characterized in that the drive device (2) has a motor-transmission module and is designed as a drive module that can be inserted into a bottom bracket shell of the bicycle, wherein the bottom bracket shell is tubular and has a profile that is closed in cross-section,wherein the electronic module (5) is removable separately from the motor-gearbox module and comprises the torque sensor (52) and the speed sensor (51), wherein the electronic module (5) comprises electrical and mechanical interfaces which are designed and positioned such that, during the insertion of the electronic module, an electrical and mechanical connection with components arranged on the drive module can be automatically established via the interfaces, wherein the electronic module (5) comprises a pivot bearing (72) for rotatably supporting the bottom bracket crankshaft (33).

Description

[0001] The invention relates to a drive device for driving a bicycle, comprising a drive motor which is operatively connected to a transmission, and with a traction mechanism carrier for a traction mechanism transmission, and with electronics, in particular with sensors.

[0002] A variety of differently designed drive devices for driving a bicycle are known from the prior art.

[0003] CN 202449162 U discloses a bicycle with a motor and a voltage wave transmission, wherein the bicycle can be driven solely by the motor or solely by the user or by a combination of the two drive types.

[0004] CN 101857063 A discloses a bicycle with a tension shaft transmission, wherein two nested freewheel clutches are provided between a transmission output and a chain carrier. CN 101 121427 A and CN 2894047 Y each describe a similar device.

[0005] CN 201385751 Y discloses an electric bicycle with a harmonic drive transmission that includes a flex pot. CN 2714417 Y also discloses an electric bicycle with a harmonic drive transmission.

[0006] CN 2312173 Y describes an e-bicycle with an electric motor, a harmonic drive transmission, and an electronic control system. The motor and transmission are coupled.

[0007] DE 10 2007 062 156 A1 discloses a bottom bracket with a torque sensor system. The bottom bracket comprises at least one crank and a shaft that is rotationally fixedly connected to the at least one crank. It further comprises a torque detection device for detecting a torque in the region of the shaft. The torque detection device comprises a first magnetization and a sensor, wherein the sensor detects a change in the first magnetization due to the torque introduced into the shaft.

[0008] CN 200988539Y discloses a bicycle with a stress wave transmission. The bicycle is powered both by a motor and by the user's pedaling. A Hall sensor measures the change in the magnetic field as the user pedals and sends a signal to the motor controller to adjust its power. This allows the total drive energy, consisting of the motor's power and the user's effort, to be kept constant.

[0009] WO 2012 / 010344 A1 discloses a bottom bracket for a bicycle. The bottom bracket comprises a bottom bracket spindle and a bottom bracket shell with two roller bearings arranged at the lateral ends of the bottom bracket shell for supporting the bottom bracket spindle. Furthermore, it comprises a torque sensor arranged within the bottom bracket shell for detecting a torque exerted on the bottom bracket spindle. The torque sensor comprises a Hall sensor, a permanent magnet, and a ferromagnetic metal pin, wherein the permanent magnet and the metal pin are arranged radially spaced from one another on the bottom bracket spindle. The Hall sensor detects a change in position between the permanent magnet and the metal pin during torsion of the bottom bracket spindle, which occurs due to the introduction of the torque.

[0010] CN 101879929 A discloses a stress wave transmission for an e-bicycle that can be driven by both an electric motor and a user. The stress wave transmission has a cup-shaped flexspline.

[0011] DE 10 2010 028 667 A1 discloses a transmission arrangement for an electric bicycle. The transmission arrangement comprises a pedal crankshaft, an electric drive gear, and an output gear. The transmission arrangement further has a crank drive transmission shaft parallel to the pedal crankshaft, as well as an output shaft surrounding the pedal crankshaft. A pedal crank drive gear is arranged on the pedal crankshaft. The pedal crank drive gear engages with a first transmission gear arranged on the crank drive transmission shaft. A second transmission gear arranged on the crank drive transmission shaft engages with a first output transmission gear arranged on the output shaft. The electric drive gear engages with a second output transmission gear arranged on the output shaft. The crank drive transmission shaft and the electric drive gear are offset from one another in the circumferential direction relative to the pedal crankshaft.The first and second transmission gears are offset in the axial direction relative to the pedal crankshaft relative to the electric drive gear.

[0012] CN 101508324 A discloses a freewheel clutch for an electric bicycle, which transmits kinetic energy of a motor to a drive chain via an internal clutch and simultaneously transmits pedaling energy to the drive chain.

[0013] The object of the present invention is to provide a drive device which is improved over the known drive devices.

[0014] The object is achieved by a drive device according to the main claim as well as a bottom bracket according to claim 14 and a bicycle according to claim 15.

[0015] The provision of an electronic module, for example separate from the drive module, or of several electronic modules that can be connected to one another offers the particular advantage that in the event of a defect in the electronics, the entire drive device no longer has to be removed, but only the electronic module.

[0016] An electronic module can advantageously be manufactured and stored separately as a standalone unit containing the electronic components in a fully interconnected manner. Furthermore, an electronic module is easier to handle than individual electronic components that are only interconnected during installation in a bicycle.

[0017] Furthermore, it can be provided in a particularly advantageous manner that the electronic module (or at least one of the electronic modules if several electronic modules are present) additionally contains mechanical components, such as a bearing for rotatably supporting a shaft.

[0018] Particularly advantageously, the electronic module (or the electronic modules, if multiple electronic modules are present) has electrical and / or mechanical interfaces to other components and / or other modules, such as electrical connectors or mechanical guides and stops. These are designed and positioned in such a way that a mechanical and / or electrical connection is automatically established during the insertion of the electronic module (or modules). This avoids complex assembly work in confined spaces when manufacturing a bicycle with a drive device.

[0019] The electronic module can, for example, be connected to the drive motor. If a control device for controlling the drive motor is not integrated into the electronic module, the electronic module can be connected to the control device, which, according to an independent inventive concept, can also be designed as a module. The connection can be established, in particular, in the manner described above via connectors that automatically come into contact when the modules are moved into their installation position.

[0020] The electronic module can have its own electronic module housing, which completely or partially encloses and / or surrounds the electronic components. It is also possible, in particular, for the components of the electronic module to be embedded in plastic, in particular injected or cast, and for the plastic to form at least part of an electronic module housing.

[0021] In particular, it can be provided that the electronic module is secured in the bottom bracket shell during insertion, preferably automatically by means of guides and / or stops, to prevent rotation. This advantageously avoids an additional work step for securing it. It also significantly simplifies disassembly, for example, in the event of a repair.

[0022] In particular, it can advantageously be provided that the motor-gearbox module and the electronics module can be inserted, in particular pushed, into a bottom bracket shell of the bicycle from different sides and / or are arranged on opposite sides of the housing. This ensures that the electronics module can be easily installed or removed.

[0023] In a special design, it is provided that a gearbox output is connected to the traction mechanism carrier in a rotationally fixed manner, regardless of its direction of rotation.

[0024] The transmission output can be connected directly or indirectly to the traction mechanism carrier. The aforementioned non-rotatable connection of the transmission output to the traction mechanism carrier ensures that the transmission output rotates in the same direction as the traction mechanism carrier, regardless of its direction of rotation.

[0025] The invention has the advantage that, due to the aforementioned connection of the transmission output to the traction mechanism carrier in the motor-side drive train, a freewheel clutch can be omitted or is unnecessary from the outset, thereby simplifying the technical design of the drive device and making the drive device more compact. In particular, the invention advantageously enables the combination of the torque generated by the drive motor with the torque applied by the pedaling rider to only occur immediately upstream of the traction mechanism carrier. In this case, it can be provided that a freewheel is present in the pedal crank-side drive train to prevent the pedal cranks from rotating in the motor-driven manner even when the rider is not pedaling.

[0026] Of course, it is not impossible for a one-way clutch to be located in the engine-side drive train. Rather, according to a special inventive concept, a one-way clutch or a switchable clutch is provided in the engine-side drive train, through which the transmission can be decoupled from the traction mechanism carrier and the driver-side drive train, or is decoupled, preferably automatically. This has the particular advantage that the pedaling driver does not have to reverse the transmission when the drive motor is switched off. In such a case, it is even possible to use a self-locking transmission.

[0027] In a preferred embodiment, the transmission is designed as a non-self-locking transmission. This ensures that the transmission output can rotate when the drive motor is switched off. In particular, it ensures that the transmission output can rotate in the same direction as the traction mechanism carrier due to a portion of the torque applied by the pedaling rider, if no coupling is provided between them.

[0028] The traction mechanism carrier can have a chainring for a chain as the traction mechanism. In particular, it can also be provided that the traction mechanism carrier has several chainrings of different sizes. Alternatively, the traction mechanism carrier can be a pulley, and the traction mechanism can be a belt, such as a V-belt, toothed belt, ribbed belt, or flat belt. Preferably, at least one further traction mechanism carrier is provided on a wheel of the bicycle, which is operatively connected to the traction mechanism carrier via the traction mechanism.

[0029] The gear can comprise a stress wave gear, in particular with a cup-shaped flexspline, or a planetary gear or a cycloidal gear.

[0030] In particular, the transmission can have a flex-pot-free stress wave transmission. Alternatively or additionally, the transmission can have a stress wave transmission whose flexspline is, in particular exclusively, annular. A transmission designed in this way offers the advantage that the drive device can be designed particularly compactly and, in particular, more installation space is available for other components, such as a drive motor or an electronics module or for torque and / or speed sensors. Therefore, according to the invention, such a stress wave transmission is particularly suitable for use in areas of a bicycle, such as in bicycle bottom brackets, where little space is available for installing the transmission.

[0031] The transmission output can have a dynamic spline and / or a circular spline.

[0032] These components can, in particular, be ring gears with internal teeth that mesh with the external teeth of a flexible gear component. This gear component (flexspline) is elastically deformable.

[0033] The traction mechanism carrier can be connected to the dynamic spline or the circular spline, in particular of a stress wave transmission, in a rotationally fixed manner, regardless of its direction of rotation. The dynamic spline or the circular spline of the transmission can be arranged stationary relative to a housing of the drive device or of a bicycle, in particular a bottom bracket shell. This means that one of the two components does not rotate during operation. The stationary arrangement can be achieved by connecting the dynamic spline or the circular spline to the housing using a connecting element, such as a screw. Of course, any other type of connection is also possible. For example, the dynamic spline or the circular spline could be pressed into the housing.

[0034] Alternatively or additionally, the dynamic spline or the circular spline of the transmission can be formed integrally with a housing of the drive device or a bicycle, in particular a bottom bracket shell. As a result, a precise, backlash-free torque transmission from the drive motor, in particular the electric motor, of the drive device to the traction mechanism carrier can be easily achieved.

[0035] The drive device is designed as a drive module that can be inserted into a tubular bottom bracket shell of a bicycle.

[0036] In particular, it can be provided that the drive module is secured in the bottom bracket shell during insertion, preferably automatically by means of guides and / or stops, to prevent rotation. This advantageously avoids an additional work step for securing it. It also significantly simplifies disassembly, for example, in the event of a repair.

[0037] For the purposes of the invention, inserting the drive module is understood to mean any possible method of inserting a drive module into a bicycle housing. A drive device housing or a drive module housing, together with the bottom bracket shell of the bicycle, can enclose a space in the housing into which the drive module has been inserted.

[0038] The electronic module can be connected to components arranged on the drive module via the interface.

[0039] The bottom bracket shell of the bicycle can be tubular. For the purposes of the invention, a tubular bottom bracket shell is understood to be a housing that has a profile that is closed in cross-section. Designing the drive device as a drive module offers the advantage that the installation or removal of the drive device in the bottom bracket shell of the bicycle, particularly in a retrofit process, is simple and quick. Furthermore, there is the particular advantage that the entire drive module can be pre-assembled separately, both spatially and temporally, and can be kept in stock as a pre-assembled subassembly and installed as needed.

[0040] The drive device can in particular be of modular construction.

[0041] Additionally, it can advantageously be provided that the motor-gearbox module and / or the electronics module each have a closure for closing the bottom bracket shell. In particular, it can be provided that a closure for closing the bottom bracket shell is integrated into the motor-gearbox module and / or the electronics module. In particular, it can alternatively or additionally also be provided that the motor-gearbox module and / or the electronics module, possibly through their closures, serve as an axial securing device for at least one shaft of the drive device.

[0042] The electronics may include a sensor, such as a torque sensor. Furthermore, the electronics may include a power unit, a memory, a control device, or the like.

[0043] The electronic module advantageously includes a pivot bearing for rotating a bottom bracket crankshaft. In a particularly advantageous embodiment, the pivot bearing is embedded in plastic, in particular, injection-molded. At least two components of the electronic module can be jointly embedded in plastic, in particular, injection-molded. In particular, for example, at least one bearing and at least one electronic unit, in particular a sensor, can be embedded in the plastic.

[0044] According to an independent, particularly advantageous inventive concept, a modular design of the drive device is realized in such a way that several modules, such as a motor-gearbox module and an electronics module and possibly further modules, are combined to produce the drive device, wherein the individual modules are each individually selected from a plurality of previously provided, different modules of the same module type and tailored to the requirements of the drive device being manufactured. For example, to produce different drive devices with different drive power, it is possible to select different motor-gearbox modules from the plurality of previously provided motor-gearbox modules and combine each with a suitable electronics module, also selected from a plurality of previously provided electronics modules.For this purpose, it is preferably provided that the interfaces of all modules of a module type are always identical, thus enabling individual combinations. Furthermore, it can advantageously be provided that the modules of a module type have the same external shape and / or require the same installation space, in order to ensure combinations even when only a predefined installation space is available, for example, in a bottom bracket shell.

[0045] According to an independent inventive concept, the drive device can have a spatially integrated control device for detecting sensor signals and / or for controlling, in particular for controlling the commutation, the drive motor. The control device can in particular be integrated into the electronics and / or an electronics module. The control device can be arranged directly on an electronics housing or electronics module housing. By arranging the control device in the electronics module, it is ensured, for example, that a defective control device can be easily replaced, namely by replacing the entire module.

[0046] By providing the control device in the drive device, it can be avoided that additional control lines have to be led out of the drive device in addition to lines for transmitting electrical drive energy.

[0047] The electronics of the drive device include at least one speed sensor and at least one torque sensor. The torque sensor can be designed to operate according to the magnetostrictive principle.

[0048] In particular, the torque sensor can be configured to directly or indirectly determine the torque acting on a shaft, in particular a shaft having a bottom bracket crankshaft, or parts of such a shaft. An indirect measurement of a torque acting on a bottom bracket crankshaft that is connectable to or is connected to pedal cranks can be achieved by measuring torsion.

[0049] However, it can also advantageously be provided that the torsion of a shaft that is not designed as a hollow shaft is measured. In particular, according to an independent inventive concept, it can also be provided that such a shaft has multiple components. The rotational speed can be determined by active or passive sensors. In particular, an inductive sensor or can be used to determine the rotational speed, for example, which detects the periodic field changes of a rotating shaft that has a magnetic marking on the outer circumference, for example a groove, a projection, or a magnet.

[0050] The drive device can have a bottom bracket crankshaft that is or is connectable to pedal cranks. The bottom bracket crankshaft can be supported on a housing of the drive device via a bearing of the transmission. In particular, it can be provided that there is no bearing that exclusively supports the bottom bracket crankshaft directly opposite the bottom bracket shell, as has been common for decades, particularly in bicycles without a drive motor. Rather, this inventive concept exploits the fact that bearings must be present in the drive train of a motor drive anyway and that, in a synergistic manner, the bottom bracket crankshaft can be supported via and / or by these (in any case necessary) bearings. In this way, both installation space and material can be saved.

[0051] The transmission bearing can, for example, support a transmission output. Alternatively or additionally, the bottom bracket crankshaft can be supported via two series-connected bearings on a housing of the drive device or on a housing, particularly a tubular one, of the bicycle, in particular on a bottom bracket shell of the bicycle. As already mentioned, it can advantageously be provided that additional components are also supported by the bearing.

[0052] In a special embodiment, the drive motor can have a hollow output shaft, which serves as the input shaft of the transmission. The hollow shaft can be arranged coaxially with a bottom bracket crankshaft. In particular, the hollow shaft can at least partially enclose the bottom bracket crankshaft. The coaxial arrangement, with the output shaft enclosing the bottom bracket crankshaft, allows for a compact design of the drive device.

[0053] According to another aspect of the invention, a bottom bracket for a bicycle is provided, which has a drive device as described above. The bottom bracket has a shaft that is or can be connected—directly or indirectly—to pedal cranks in a rotationally fixed manner. Furthermore, the bottom bracket has a torque sensor that detects torsion of the shaft.

[0054] In particular, and according to an independent inventive concept, the shaft can be designed not as a hollow shaft, but as a solid shaft, in particular a multi-component one. By providing a non-hollow shaft, the accuracy of torque detection can be improved, which is briefly explained below.

[0055] For example, the shaft can have an outer transmission shaft, an intermediate section, and an inner bottom bracket crankshaft as individual components, wherein the components are preferably arranged coaxially to one another. The outer transmission shaft is preferably made of a magnetic or magnetizable material, while the intermediate section is preferably made of a non-magnetic material and is preferably arranged to be at least partially movable relative to the transmission shaft and / or the bottom bracket crankshaft. At the very least, the mobility should be such that the transmission shaft can be twisted independently of the bottom bracket crankshaft. Because the transmission shaft can be supported on the bottom bracket crankshaft via the intermediate section and is therefore subject to little or no bending stress, the transmission shaft can be designed with particularly thin walls and thus be particularly easy to twist.This makes the torque measurement based on a torsion measurement (for example according to the magnetostrictive principle) on the transmission shaft more accurate because the same acting torque is assigned a larger torsion, which can therefore be measured with greater accuracy.

[0056] As mentioned, it can generally be provided that the torque sensor detects torsion of the transmission shaft. The transmission shaft can be made of a first material, and the intermediate section can be made of a second material, different from the first material, in particular entirely. For example, the intermediate section can be made of a preferably non-magnetic material with low static and sliding friction, for example a plastic, in particular Teflon.

[0057] The transmission shaft can, as already mentioned, surround the intermediate section. The intermediate section can at least partially surround the bottom bracket crankshaft. The transmission shaft can have a different elasticity and / or torsional rigidity than the intermediate section. Furthermore, the transmission shaft and the intermediate section can be movable, in particular rotatable, relative to one another, so that torque detection is possible. In an alternative embodiment, the intermediate section can be an air gap that separates the transmission shaft from the bottom bracket crankshaft at least in a partial area.

[0058] According to a special, independent inventive concept, it is provided that the shaft, which has a bottom bracket crankshaft and / or is designed as a bottom bracket crankshaft, is supported by means of a bearing that is arranged in a common plane with the traction mechanism carrier. Arranging the bearing and the traction mechanism carrier in a common plane offers the advantage that no torque caused by the traction mechanism carrier acts on the bearing and that more installation space is available for other components within a housing, in particular a bottom bracket shell. The bearing can in particular also be a bearing that additionally supports other components of the drive device, in particular the transmission, as already described above.

[0059] The bearing and the tension member share a common plane even if the center plane of the bearing is offset relative to the plane. In particular, the bearing and the tension member may share a common plane, as long as the bearing is not offset relative to the tension member to such an extent that no component of the bearing is intersected by the plane. In a special embodiment, a vertical axis of the bearing and the tension member share a common plane. The center plane of the bearing is perpendicular to the shaft axis.

[0060] The drive device can be arranged in a bottom bracket shell, in particular a tubular one, of the bottom bracket. Furthermore, a control device for detecting sensor signals and / or for controlling, in particular for controlling the commutation, of the drive motor can be arranged in the bottom bracket shell.

[0061] The drive unit and bottom bracket described above can be used in a bicycle. Of course, the use of the drive unit and bottom bracket is not limited to bicycles.

[0062] The subject matter of the invention is shown schematically in the drawing and is described below with reference to the figures, wherein identical or similarly acting elements are generally provided with the same reference numerals. In the drawings: Fig. 1 a schematic representation of a bottom bracket according to a first embodiment with a drive device in which a transmission output is connected to a traction mechanism carrier in a rotationally fixed manner, regardless of the direction of rotation, Fig. 2 is a schematic representation of a bottom bracket according to a second embodiment with a drive device in which no coupling is provided between the shaft and the transmission output, Fig. 3 a schematic representation of a bottom bracket according to a third embodiment with a drive device with a switchable clutch between the transmission output and the traction mechanism carrier, Fig. 4 a schematic representation of a bottom bracket according to a fourth embodiment with a drive device having a cup-shaped flexspline as a transmission output, Fig. 5 is a schematic representation of a bottom bracket according to a fifth embodiment not according to the invention with a drive device that has no electronics, Fig. 6 a schematic representation of a bottom bracket according to a sixth embodiment with a drive device, wherein a bearing for a crankshaft and a traction mechanism carrier are arranged in a common plane, Fig. 7 a perspective view of an electronic module according to the invention.

[0063] The Fig. The bottom bracket 1 shown in Figure 1 according to a first embodiment has a drive device 2 with an electronic module 5 (not shown in this figure), which is designed as a drive module and has been inserted into a bottom bracket shell (not shown). The bottom bracket 1 is used, for example, in bicycles.

[0064] The drive device 2 has a drive motor 20, which is operatively connected to a non-self-locking gear via an external toothing of a motor output shaft 21. The gear has an annular flexspline 22, which is connected to the motor output shaft 21 via an internal toothing. The motor output shaft 21 is connected via an external toothing to a circular spline 23 and a gear output in the form of a dynamic spline 24.

[0065] The circular spline 23 is connected to a drive device housing (not shown) and is arranged stationary relative thereto, while the dynamic spline 24 is arranged rotatably. The dynamic spline 24 is directly and non-rotatably connected to a traction mechanism carrier 4 of a traction mechanism transmission. The dynamic spline 24 is connected to the traction mechanism carrier 4 in such a way that the dynamic spline 24 can rotate together with the traction mechanism carrier 4 in both directions.

[0066] The bottom bracket 1 has a shaft 3 that extends through the bottom bracket shell and drive device housing (not shown). The shaft 3 has a transmission shaft 31, an intermediate section 32, and a bottom bracket crankshaft 33. The bottom bracket crankshaft 33 is connected to a pedal crank 30 at each of its two ends. The transmission shaft 31 is connected to the bottom bracket crankshaft 33 in a rotationally fixed manner and runs essentially parallel to it. The transmission shaft 31 encloses the intermediate section 32, and the intermediate section 32 encloses part of the bottom bracket crankshaft 33. The intermediate section 32 can be made of a solid, in particular non-magnetic and non-magnetizable, material that has a different torsional rigidity and / or elasticity than a material of the transmission shaft 31. Alternatively, the intermediate section can be an air gap that separates the transmission shaft from the bottom bracket crankshaft 33.

[0067] The transmission shaft 31 can rotate relative to the intermediate section 32 and can preferably be twisted independently of the intermediate section. The torsion of the transmission shaft 31 correlates with the torque applied to the bottom bracket crankshaft 33 and is detected by a torque sensor 52.

[0068] In addition, the rotational speed of the bottom bracket crankshaft 33 is detected. For this purpose, a speed sensor 50 arranged on the bottom bracket crankshaft 33 and a stationary speed sensor 51 are provided. The values determined by the sensors are transmitted to a control device (not shown).

[0069] The transmission shaft 31 is coupled via a clutch 6 to the transmission output or the dynamic spline 24 and thus to the traction mechanism carrier 4. The freewheel clutch 6 is designed such that a torque is transmitted from the transmission shaft 31 to the traction mechanism carrier 4 in a single direction of rotation.

[0070] The bottom bracket crankshaft 33 is supported by a first bearing 70, in particular an inner ring of the first bearing 70. The transmission output is also supported by the first bearing 70, in particular an outer ring of the first bearing 70. Furthermore, the transmission output is supported by a second bearing 71.

[0071] The following describes the operating procedure of the Fig. 1. When a cyclist operates the pedal cranks 30, the bottom bracket crankshaft 33 is rotated. As a result of the rotation of the bottom bracket crankshaft 33, the transmission shaft 31 also rotates. The provision of the freewheel clutch 6 ensures that torque is transmitted in only one specific direction to the transmission output or to the dynamic spline 24 and thus to the traction mechanism carrier 4.

[0072] The torque sensor 52 and the speed sensor 51 detect the speed and torque and transmit them to the control device. Based on these values, the control device determines the torque to be generated by the drive motor 20 and supplies it with current. The torque from the output shaft 21 of the motor 20 is transmitted via the flex spline 22 to the transmission output or the dynamic spline 24. As a result, in addition to the torque generated by the cyclist, a torque generated by the drive motor 20 is transmitted to the traction mechanism carrier 4.

[0073] The torque sensor 52, the speed sensor 51 and an electronic module bearing 72 are arranged in an electronic module which is detachably connected to the drive device 2.

[0074] The Fig. 2 illustrated bottom bracket 1 according to a second embodiment essentially corresponds to the one shown in Fig. 1 shown bottom bracket according to the first version. Therefore, only the difference between the two bottom brackets will be discussed below. The only difference between the two bottom brackets is that in the Fig. 2, no coupling is arranged between the transmission shaft 31 and the transmission output or the Dynamic Spline 24. This means that in this embodiment, the torque provided by the transmission shaft 31 is transmitted to the transmission output and thus to the traction mechanism carrier 4, regardless of the direction of rotation of the transmission shaft 31.

[0075] The Fig. 3 shown bottom bracket 1 according to a third embodiment differs from that in Fig. 1 in that a further, in particular switchable, clutch 60 is arranged between the dynamic spline 24 and the traction mechanism carrier 4. In a first switching position of the further clutch 60, a torque can be transmitted from the output shaft 21 via the transmission output or the dynamic spline 24 to the traction mechanism carrier 4. In a second switching position, a torque transmission from the transmission output to the traction mechanism carrier 4 is not possible. The second switching position is useful when the drive motor 20 is not providing any torque.

[0076] Thus, in the second switching position of the further clutch 60, the torque transmitted from the transmission shaft 31 via the clutch 6 is completely transmitted to the traction mechanism carrier 4. Therefore, in contrast to the Fig. 1 and Fig. 2, there is no loss of torque in the form that part of the torque transmitted from the shaft to the gearbox output causes an actually undesirable drive of the motor output shaft 21.

[0077] The Fig. 4 shown bottom bracket 1 according to a fourth embodiment differs from the ones shown in the Fig. 1 to 3 in the design of the transmission output. Thus, in the Fig. No dynamic spline is provided for the bottom bracket 1 shown in Figure 4. The motor output shaft 21 is connected to a cup-shaped flexspline 22' via external teeth, with the flexspline 22' being rotatable. The cup-shaped flexspline 22' is connected to the circular spline 23 via external teeth.

[0078] Furthermore, the cup-shaped flexspline is connected to the traction mechanism carrier 4 at a cup bottom and thus transmits the torque provided by the drive motor shaft 21 to the traction mechanism carrier 4. The coupling 6 is provided at the cup bottom, ensuring that a torque provided by the transmission shaft 31 is transmitted to the cup-shaped flexspline 22' in only one direction. Of course, the coupling 6 could also be arranged in an area between the cup bottom and a coupling area between the transmission shaft 31 and the bottom bracket crankshaft 33, which is not shown in the figure.

[0079] The Fig. The bottom bracket 1 shown in Fig. 5 according to a fifth embodiment not according to the invention differs from the one shown in Fig. 1 is that no torque and speed measurement is carried out. Accordingly, the Fig. 5 also does not have a torque sensor or a speed sensor. This means that in the Fig. 5, no electronic module is present. The drive motor 20 can be controlled, for example, using a stored characteristic curve.

[0080] Fig. 6 shows a bottom bracket 1 according to a sixth embodiment. Fig. 6 shows a different bottom bracket from the one in Fig. 1 in that the first bearing 70' is arranged such that the first bearing and the traction mechanism carrier 4 have a common plane E. The first bearing 70 serves to support the transmission output or dynamic splines 24 and the bottom bracket crankshaft 33.

[0081] Fig.Figure 7 shows an electronic module 5 that can be connected to the drive module. The electronic module 5 includes the speed sensor 51 and the torque sensor 52. These are connected to a control device (not shown) via a connecting line 53. List of reference symbols: 1 bottom bracket 2 drive device 3 Wave 4 traction mechanism carriers 5 Electronic module 6 Clutch 20 drive motor 21 Output shaft 22 Flexsplines 22' cup-shaped flexspline 23 Circular Spline 24 Dynamic Spline 30 cranks 31 Transmission shaft 32 Intermediate section 33 Bottom bracket crankshaft 50 speed sensors 51 Speed sensor 52 torque sensor 53 connecting line 60 switchable clutch 70, 70' first camp 71 second camp 72 electronic module warehouses E Level

Claims

[1] Drive device (2) for driving a bicycle, comprising a drive motor (20) which is operatively connected to a transmission, and with a traction mechanism carrier (4) for a traction mechanism transmission and with electronics which have a torque sensor (52) and a speed sensor (51), and a control device integrated into the electronics for controlling the drive motor (20), wherein the electronics are formed from at least one electronic module (5), wherein the drive motor (20) has an output shaft (20) designed as a hollow shaft, which is arranged coaxially to a bottom bracket crankshaft (33), characterized byin that the drive device (2) has a motor-gearbox module and is designed as a drive module that can be inserted into a bottom bracket shell of the bicycle, wherein the bottom bracket shell is tubular and has a profile that is closed in cross-section, wherein the electronics module (5) can be removed separately from the motor-gearbox module and has the torque sensor (52) and the speed sensor (51), wherein the electronics module (5) has electrical and mechanical interfaces that are designed and positioned in such a way that an electrical and mechanical connection to components arranged on the drive module can be automatically established via the interfaces during the insertion of the electronics module, wherein the electronics module (5) has a pivot bearing (72) for the rotatable mounting of the bottom bracket crankshaft (33). [2] Drive device (2) according to claim 1, characterized bythat the gearbox has a flex-pot-free stress wave gearbox and / or that the gearbox has a stress wave gearbox whose flexspline is ring-shaped. [3] Drive device (2) according to claim 1 or 2, characterized by that a gearbox output is connected to the traction mechanism carrier (4) in a rotationally fixed manner, regardless of its direction of rotation. [4] Drive device (2) according to the preceding claim, characterized by that the electronic module (5) contains a bearing (72), at least one sensor (51, 52) and / or a power unit and / or that at least two components of the electronic module (5) are embedded together in plastic. [5] Drive device (2) according to claim 4, characterized by , that a. the drive device (2) has a control device for detecting sensor signals or that b. the drive device (2) has a control device integrated into the electronics for detecting sensor signals. [6] Drive device (2) according to one of the preceding claims, characterized by that the drive device (2) has a bottom bracket crankshaft (33) which can be connected to pedal cranks (30), wherein the bottom bracket crankshaft (33) is not supported directly, but indirectly via the transmission and / or via a bearing of the transmission on a housing of the drive device (2) or on a housing of the bicycle. [7] Drive device (2) according to the preceding claim, characterized by , that a. the gearbox bearing supports a gearbox output and / or that b. the bottom bracket crankshaft (33) is supported on a housing of the drive device (2) via two bearings (70, 72) connected in series. [8] Drive device (2) according to one of the preceding claims, characterized by , that a. the transmission output has a dynamic spline (24) or a circular spline (23) or that b. the traction mechanism carrier (4) is connected in a rotationally fixed manner to a dynamic spline (24) or a circular spline (23), regardless of its direction of rotation. [9] Drive device (2) according to one of the preceding claims, characterized by that a Dynamic Spline (24) or a Circular Spline (23) of the transmission a. is arranged stationary relative to a housing of the drive device (2) or a bicycle, and / or b. is formed integrally with a housing of the drive device (2) or of a bicycle. [10] Drive device (2) according to one of the preceding claims, characterized by that the gearbox is not self-locking or can be released by a clutch. [11] Drive device (2) according to one of the preceding claims, characterized bythat the drive device (2) has a speed sensor (51) and a torque sensor (52) and a control device. [12] Drive device (2) according to the preceding claim, characterized by , that a. the torque sensor (52) operates according to the magnetostrictive principle and / or that b. the torque sensor (52) determines the torque acting on a bottom bracket crankshaft (30). [13] Drive device (2) according to one of the preceding claims, characterized by that the pivot bearing (72) is embedded in plastic. [14] Bottom bracket (1) with a drive device (2) according to one of the preceding claims. [15] Bicycle with a drive device (2) according to one of claims 1 to 13 or a bottom bracket (1) according to the preceding claim.

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