WO2023222259A1

WO2023222259A1 - Bottom bracket gear shift device with actuation device for a bicycle, and bicycle comprising such a bottom bracket gear shift device

Info

Publication number: WO2023222259A1
Application number: PCT/EP2023/051067
Authority: WO
Inventors: Karlheinz Nicolai
Original assignee: Karlheinz Nicolai
Priority date: 2022-05-17
Filing date: 2023-01-18
Publication date: 2023-11-23
Also published as: DE102022001738A1; TW202408872A

Abstract

The invention relates to a bottom bracket gear shift device (10) with an actuation device (85), in particular for a muscle-powered vehicle, comprising a gearing mechanism that has a selector shaft (67) on which a plurality of idler wheels (109) are mounted, said idler wheels forming wheel pairs (189) together with a corresponding plurality of gear wheels, wherein the idler wheels (109) can be connected to the selector shaft (67) by means of coupling bodies (58). The bottom bracket gear shift device is characterized in that a speed modulation gearbox (170) is arranged within the actuation device (85), and the selector shaft (67) is rigidly connected to a reference gear wheel (69). The reference gear wheel (69) is located laterally next to and coaxially to the selector shaft (67). Furthermore an actuation gear wheel (68) is located coaxially to the reference gear wheel (69) and laterally next to the reference gear wheel (69). The actuation gear wheel (68) is formed with an outer toothing and an inner toothing (71), and the inner toothing of the actuation gear wheel (68) is directly or indirectly connected to the shifting means or the coupling means. The outer toothing of the actuation gear wheel (68) is additionally in engagement with an actuation gear wheel of the speed modulation gearbox (178), and the outer toothing of the reference gear wheel (69) is likewise in engagement with a reference gear wheel of the speed modulation gearbox (177). The actuation gear wheel of the speed modulation gearbox (178) and the reference gear wheel of the speed modulation gearbox (177) are arranged coaxially to each other and are not coaxial to the selector shaft (67).

Description

Bottom bracket gear with actuating device for a bicycle and a bicycle with such a bottom bracket gear

The invention relates to a bottom bracket circuit with an actuating device for a bicycle and a bicycle with such an actuating device for a bottom bracket circuit.

If the following description refers to a bottom bracket circuit with an actuating device, this also means an actuating device for a bottom bracket circuit. It should also be noted at this point that the terms bottom bracket gear, bottom bracket gear, multiple gear or gear unit are often used in the literature and patents for the same thing. In addition, it should be noted at this point that the terms clutch device and switching device are also often used in the literature and patent specifications for the same thing.

Bicycles optionally also have an auxiliary drive that supports the pedaling movement of a cyclist. These bicycles are then also called electric bicycles. Gear shifting on a bicycle ensures that you can pedal over a wide speed range with an approximately constant cadence.

The auxiliary drive of the electric bicycles considered here is located near the bottom bracket. In this configuration, derailleur gears or hub gears are usually used because there is not enough space at the bottom bracket. However, derailleur gears are disadvantageous in that the components of the gear shift, namely the sprockets on the rear hub, the at least one chainring and the chain and the chain derailleur are unprotected and therefore easily dirty. A derailleur gear is therefore comparatively maintenance-intensive.

Hub gears are used instead of or together with derailleur gears on the rear wheel. The hub gears are encapsulated from the outside environment and arranged in a housing and are therefore largely maintenance-free. However, the disadvantage of hub gears is the high weight on the rear wheel, which leads to an unfavorable weight distribution. The high weight on the rear wheel hub is disruptive not only when carrying, but also when cornering or during sporty off-road driving.

A significantly more advantageous weight distribution results when the gear shifter is positioned in the middle of the bicycle, as is the case with bottom bracket shifters, for example. However, bottom bracket gears are quite large, so there is no space around the bottom bracket for the electric motor. In addition, the bottom bracket gears are already so heavy that this The additional weight of an auxiliary drive would result in an electric bicycle that would be too heavy for everyday use or to continue riding when the battery is empty.

As early as the 1950s, bicycles of the NSU Quickly brand were built in series with auxiliary drive and gear shifting near the bottom bracket. DE967668 is mentioned as an example here. Here the driver could already adjust his cadence to the driving speed by selecting different gears.

A manual transmission with an auxiliary drive is also known from DE19750659A1 and US2011/0120794A1, which is arranged near the bottom bracket. Unfortunately, these constructions are relatively large and heavy, which can be seen as a disadvantage. Another disadvantage of these designs is that it is not possible to change gears under load without interrupting the pedaling movement.

Over the years, bottom bracket gears on bicycles have been further developed. In terms of size and weight, a structure of the manual transmission according to EP1445088A2 is advantageous. This is a transmission unit of a vehicle powered by muscle power, with a first shaft, which is usually arranged parallel to the bottom bracket shaft and on which a plurality of idler gears are mounted, and a corresponding number of gears, which are mounted on at least one second shaft , wherein the idler gears can each be connected to the first shaft by means of coupling means, the first shaft being designed as a hollow shaft and having one or two coaxially internal switching pins, characterized in that the switching pin or pins is or are connected to drive means which are designed for this purpose to move the switching pin(s) axially for actuation. The first wave is also often called the switching wave. The coupling means, also often called switching clutches or switching means, are designed as positive freewheels and are arranged on axially displaceable switching pins. Freewheel bodies are therefore arranged on the switching pins.

A torque, which is introduced by the cyclist onto the gearbox while driving and also during the switching process, must be transmitted from the shaft via the coupling means into the respective gear. Shifting under load is very difficult with this type of manual transmission, since the more torque the driver introduces, the more difficult it is for the axial movement of the clutch means to occur. The cause is the increased surface pressure between the force-transmitted components.

The actuating means, which are also often called drive means, are no longer able to move the clutch means when shifting under load due to the increased surface pressure. The switching force is the force that the actuating means must apply to the clutch means to move. If the shifting force within a transmission increases depending on the driver's torque, this should be seen as a major disadvantage inherent in the system.

Manual transmissions according to the state of the art have this inherent disadvantage. If you look at EP 2 379402 B2, each individual idler gear can be coupled to the shift shaft with the help of one freewheel tooth, which is movably arranged on the shift shaft. The freewheel teeth are constantly pressed by springs towards the clutch teeth of the idler gears. The geometry of the freewheel teeth is chosen so that they remain reliably engaged in the clutch teeth of the idler gear under load and no reaction force is created in the direction of the actuating means during operation. The actuating means, which in this design rotates within the switching shaft as a camshaft, must release the relevant freewheel tooth from its positive locking position when shifting under load and thereby overcome enormous frictional forces. Here too, the switching force increases when the user feeds increased torque into the bottom bracket shaft via the pedals. This can be seen as a disadvantage.

If you look at the patent DE 10 2013 112 788 B4 or US10526044B2, the switching behavior under load is improved by an optimized shape of the actuating means, but the fact that the frictional forces between the freewheel teeth and the internal teeth of the idler gears is still completely controlled by the actuating means must be overcome is seen as a disadvantage of this design.

According to the prior art, the actuating means as part of the entire actuating device is usually operated by the human hand on the handlebars of the bicycle. In new designs according to the prior art, actuation by electrical actuators is also common. Since the human hand and also small electric motors, such as those used in actuators, can only perform a limited amount of mechanical work, there is a need for an actuating device for a bottom bracket circuit with low switching forces and improved power shifting behavior.

When cycling, the pedals should never slip while changing gears. The cyclist must not suddenly step “into the void”. This can cause injuries, especially in the knee area. Many prior art transmissions are constructed in such a way that no idling between individual gears can occur during gear changes. The patent specification DE102004045364.0 is cited as an example here. The coupling means have a freewheeling function and can be controlled from the outside by an actuating means. This bottom bracket gear is characterized in that the state of at least two coupling means changes simultaneously during the switching process. Controlling the change in the state of the clutch means during the switching process so that idling does not occur is achieved in this way.

Another example of good execution can be found in patent specification WO 2009/132605 A1. This version also has many idler gears that are mounted side by side on a shaft and can be connected to the shaft using switchable freewheels. So that slipping cannot occur in any situation, there is always a certain period of time between 2 gears during the shifting process, during which two freewheel bodies are actuated and are actively pressed into the internal teeth of the idler gears and thus ensure in one direction of rotation that one of the two relevant idler gears can transmit torque to the shaft.

If one considers gearboxes according to the prior art, as shown, for example, in patent specification EP 1982913A1, here too the coupling means are controlled by rotation of the actuating means. Since the actuating means is located as part of the actuating device on a shaft that rotates while driving, the switching command must be transmitted from the stationary housing to the rotating shaft using a superposition gear. If the superposition gear, which is usually designed as a planetary gear, is located coaxially and laterally next to the switching shaft according to the prior art, the overall width of the gear increases disadvantageously.

The Q factor on a bicycle determines the stance width and describes the lateral distance between the mounting points of the pedals on the cranks. If the gearbox housing exceeds a certain width, the Q factor becomes too large and this has ergonomic and biomechanical disadvantages.

There is therefore a need for a bottom bracket gearshift with an integrated actuating device within a narrow gearbox housing. If state-of-the-art transmissions are also required to have a high number of usable gears, two gear stages are often switched in series to achieve this goal.

Such a structure is clearly visible, for example, in Figure 1 in the patent specification US5924950 or in Figure 8 from EP1445088A2. In this case, these gearboxes have several actuation means that have to be controlled by the user at the same time in the case of certain gear changes. The need for the user of the bicycle to operate the actuation means twice is disadvantageous. It would be advantageous to have an actuator that solves this problem.

The user just wants to trigger an operating command to change from one gear to another gear. In order to implement this function, the person skilled in the art is familiar with the so-called stepping gears. Here, for example, a mechanical input movement is divided into two output movements with different timing. An axially particularly space-saving stepping gear from Siemens is known, for example, from patent DE1113618.

Transmissions that control several actuating means and coupling means simultaneously using stepper gears are known, for example, from the patents FR2776613A1, DE102009060484B4 or DE000019720794A1. In the versions mentioned, however, there is usually only a limited installation space available for the stepper gearbox, so that only a limited switching force can be transmitted.

In order to achieve power shifting capability, a high switching force is required. There is therefore a need for a bottom bracket shifter with enough space for an actuating device that contains at least one superposition gear and a stepper gear, so that these gears can also transmit high switching forces when shifting under load. The entire installation space of the bottom bracket gear should also be as small as possible towards the rear wheel so that there is enough space for the tires, a short chainstay length and also enough space for pivot points for optimal suspension kinematics.

There is therefore a need for an actuating device for the bottom bracket gears of a bicycle that is so small and narrow that it can optionally be combined with an auxiliary drive on the bottom bracket, is light in weight and is compatible with modern suspension designs. In addition, there is a need for an actuating device for bottom bracket gearshifts with improved powershift behavior, although the pedals must not slip in any driving or switching situation. The switching forces should be reduced compared to the state of the art.

Electric bicycles without bottom bracket shifting according to the state of the art have enough space in their housing to accommodate a technologically required torque sensor and a To accommodate a speed sensor. The sum of all sensors and electronic components that are used within an electric bicycle with an auxiliary drive, in particular in the form of a mid-engine, to generate signals that are necessary for controlling or regulating the motor in the manner desired by the user are referred to below as Sensor arrangement referred to.

In order to solve the problems described above of integrating an advantageous bottom bracket shifter into an electric bicycle with an auxiliary drive, especially in the form of a mid-engine, a very light and compact transmission with a narrow sensor arrangement is required. The gears within the transmission, which on the one hand reduce the speed of the electric motor and the gears which are responsible for the switching function as drive, output and idler gears, cannot be manufactured in the classic way using the hobbing method, otherwise they would require a lot would become too heavy and would also take up too much space. However, this installation space is required for the actuating device.

There is therefore a need for an improved actuation device for a bottom bracket shifter of a bicycle. For this purpose, in addition to the sensor arrangement, the gears must also be improved and should have a shape that leads to a low mass and a narrow overall width of the bottom bracket circuit so that the actuating device can be integrated into the available installation space without deteriorating the Q factor.

The invention solves these problems by a bottom bracket circuit according to claim 1.

An advantageous embodiment of the bottom bracket circuit with an actuating device, in particular for a vehicle powered by muscle power, with a transmission, the transmission having a switching shaft on which a plurality of idler gears are mounted, which form wheel pairs with a corresponding plurality of gears, the idler gears can be connected to the switching shaft using coupling bodies, is characterized by any combination of the following features to solve the problem:

A. a superposition gear (170) is arranged within the actuating device (85),

B. the switching shaft (67) is firmly connected to a reference gear (69),

C. the reference gear (69) is located laterally next to and coaxial with that of the switching shaft (67),

D. an actuating gear (68) is located coaxially with the reference gear (69) and laterally next to the reference gear (69), E. the actuating gear (68) is designed with external teeth and internal teeth (71),

F. the internal teeth of the actuating gear (68) are directly or indirectly connected to the switching means or the coupling means,

G. the external teeth of the actuating gear (68) are in engagement with an actuating gear of the superposition gear (178),

H. the external teeth of the reference gear (69) are in engagement with a reference gear of the superposition gear (177),

I. the actuating gear of the superposition gear (178) and the reference gear of the superposition gear (177) are arranged coaxially to one another and are not coaxial with the switching shaft (67).

Because a superposition gear is arranged within the actuating device and the actuating gear of the superposition gear and the reference gear of the superposition gear are designed with external teeth and internal teeth, the superposition gear can be arranged parallel to the shift shaft to save space and the overall width of the bottom bracket gear remains advantageously narrow.

An actuator can be arranged in a space-saving manner within the actuating device if an actuating sun gear is arranged concentrically to the reference gear of the superposition gear.

Components are saved if the bottom bracket circuit is characterized in that a sun gear fixed to the housing is arranged concentrically to the actuating gear of the superposition gear and this sun gear fixed to the housing is connected directly or indirectly, at least in a twisted manner, to a frame or housing. The sun gear fixed to the housing can thus be manufactured in one piece together with a housing wall.

The bottom bracket circuit is preferably characterized in that the actuating sun gear can be rotated through an angle relative to a frame or housing in order to actuate the bottom bracket circuit. This configuration is advantageous because by arranging an actuation interface you can not only use an electrically operated actuator to carry out the switching process, but also simple and inexpensive controls within the actuation device via a cable, hydraulics or other actuations as required can integrate the technology. If the actuating gear of the superposition gear and the reference gear of the superposition gear and the actuating sun gear and the sun gear fixed to the housing are arranged as a planetary gear, the entire actuating device only requires a small installation space. It should be noted that the planetary gear should preferably not be coaxial with the shift shaft.

The superposition gear has a simple structure and can be produced inexpensively using the sintering process if it is characterized in that within the planetary gear there are planetary gears which are connected to one another via planetary gear axles and at least one planetary gear is in engagement with the actuating sun gear and at least one further planetary gear is in engagement with the The sun gear fixed to the housing is engaged and wherein within the planetary gear there are planet gears which are connected to one another via planetary gear axles and wherein at least one planet gear is in engagement with the reference gear of the superposition gear and at least one further planet gear is in engagement with the actuating gear of the superposition gear. The planetary gear becomes fully functional as a superposition gear when the planetary gear axles are arranged on the web of the planetary gear.

In an advantageous embodiment, the actuating device does not spread the housing when the reference gear of the superposition gear and the reference gear are coplanar to one another and when their axes of rotation are parallel to one another.

The same advantage of a narrow design results when the actuating gear of the superposition gear and the actuating gear are arranged coplanar to one another and their axes of rotation are parallel to one another.

The narrow design can also be further reduced if the actuation gear is rotatably mounted directly on the reference gear for the actuation.

If the bottom bracket circuit with preferred actuating means, in particular for a vehicle powered by muscle power with an electric auxiliary drive, is characterized in that a first sub-transmission and a second sub-transmission are connected in series for power transmission, the first sub-transmission and the second sub-transmission having a shift shaft in which a plurality of idler gears are mounted, which form wheel pairs of the respective sub-transmission with a corresponding plurality of gears and these idler gears can be connected to the shift shaft by means of coupling bodies, then bottom bracket gears can be implemented with a large number of gear stages. The superposition gear can be advantageously positioned within the transmission if the outside diameter of the reference gear and the outside diameter of the actuating gear are larger than the outside diameter of the switching shaft. In this way, there is no interference between the gear parts of the superposition gear and the actuator with the idler gears, since superposition gear can be placed far enough away and parallel spaced.

A very simple connection between the actuating device and the switching means can be achieved if the actuating gear has internal teeth in addition to the external teeth, the internal teeth being connected to at least two pinions, these pinions being at least indirectly connected to the pivotable supports.

A large number of gears can only be easily operated in the bottom bracket transmission if the switching means of two or more gear stages can be operated simultaneously. A preferred narrow actuation is achieved if the bottom bracket circuit is characterized in that the axis of rotation of the shift shaft is arranged coaxially to the axis of rotation of the stepper gear and the stepper gear is located at least to a large extent laterally next to the shift shaft.

The actuating device can be operated easily and with little energy and good efficiency if the bottom bracket gear is characterized in that a switching process is initiated at least when the actuating gear is rotated relative to the reference gear and this rotation is triggered via a superposition gear. If this superposition gear is then additionally spaced parallel to the axes of rotation and not coaxial with the switching shaft, the narrow design is achieved in an advantageous manner.

Simple operation from the handlebars of the bicycle is possible if the bottom bracket circuit is characterized in that a signal that the cyclist triggers on a control element indirectly triggers or causes an angular rotation on the actuation sun wheel of the actuation device.

Analogously to this, preferred actuation from the handlebars of the bicycle is easily possible if the signal that the cyclist triggers on a control element also indirectly triggers or causes an activation of the servomotor assembly with gear. Housing components are saved if the servomotor assembly with gear is arranged within the actuating device and is in a torque-transmitting connection directly with the actuating sun gear. Analogously to this, the same housing can also preferably be used to achieve detection of the engaged gear by arranging a sensor within the actuating device.

The sensor for gear stage detection is preferably connected directly or indirectly to the actuating sun gear or to the servomotor assembly with transmission. In this embodiment, the installation space within the actuating device is well utilized.

The actuating device achieves good shiftability under load if there are at least two pivotable supports within the switching shaft, which are equipped with a pinion at their ends and are directly or indirectly in engagement with the internal teeth of the actuating gear.

The actuating device is able to preferably also control the clutch means of different gear stages simultaneously if the bottom bracket circuit is advantageously characterized in that the reference gear is firmly connected to a short cylindrical ring on a side surface, the ring being arranged concentrically to the reference gear and a Has a surface that can come into contact with a ball and the surface has depressions that form a backdrop-like surface. This simultaneous control is preferably made possible in that the actuating gear is firmly connected to a short cylindrical ring on one side surface, the ring being arranged concentrically to the actuating gear and the ring having a groove or opening in which the ball is movably arranged and wherein the ring is disposed proximate and rotatable relative to the cylindrical ring on the reference gear. In addition, the simultaneous control is preferably made possible in that a ring gear has internal toothing, the internal toothing being in mesh with at least two toothed pinions, the two toothed pinions being connected to pivotable supports and the ring gear being located concentrically to the actuating gear and the Ring gear has a surface that can come into contact with a ball and the surface has depressions or depressions into which the ball can snap.

In an advantageous embodiment, the stepping gear can be easily integrated into the actuating device and can control two gear stages if the bottom bracket shift is thereby activated is characterized in that at least partially during the switching processes within the actuating device, the ring gear can assume a first state in which it moves in the same direction together with the actuating gear relative to the switching shaft and can assume a second state in which it does not carry out any rotary movement relative to the switching shaft .

The invention is explained below by way of example with reference to the accompanying drawings using exemplary embodiments. According to the above embodiments, individual features can be omitted if the technical effect of a feature in a particular application is not important. Conversely, a feature that is not described or shown in an exemplary embodiment can be added if the technical effect of this feature in a specific application is important.

In the drawings, the same reference numerals are used for elements that correspond to one another in terms of structure and/or function.

Show it:

Fig. 1 A side view of an electric bicycle with a bottom bracket shifter in a first embodiment.

Fig. 2 A perspective view of the bottom bracket circuit from Figure 1 from the left rear.

Fig. 3 A side view of the bottom bracket gear from the right.

Fig. 4 A sectional view through the plane that is spanned by the axis of rotation of the bottom bracket shaft and by the axis of rotation of the shift shaft.

Fig. 5 A cross section through the plane AB from Figure 4.

Fig. 6 A perspective view of the bottom bracket circuit from Figure 2 without the housing.

Fig. 7 A perspective view of the assembly of the switching shaft.

Fig.8 Sections through an idler gear of the bottom bracket shifter viewed from the left in different states.

Fig. 9 Schematic representations of the switching states from Figure 8.

Fig. 10 Schematic representation of the coupling means in comparison to the prior art. Fig. 11 The switching shaft and the coupling means in a detailed perspective view.

Fig. 12 A section through the actuating gear of the switching shaft of the bottom bracket gearshift.

Fig. 13 A section through the stepper gear of the shift shaft of the bottom bracket gearshift.

Fig. 14 A schematic representation of the right end of the switching shaft and the actuating means within the actuating device.

Fig. 15 Different representations of the idler gear 51 from Figure 4.

Fig. 16 A perspective view of the output gears.

Fig. 17 A perspective view of the drive gears.

Figure 1 shows the side view of an electric bicycle with bottom bracket shifting in a first embodiment. In an advantageous embodiment, the electric drive motor is also integrated in the bottom bracket circuit. The frame 1 is assembled from a top tube 2, a down tube 3 and a seat tube 4. The battery 5 is integrated around the down tube 3. At the lower end of the seat tube 4 and the down tube 3 there is a holder 9 into which the bottom bracket circuit 10 is screwed. The rear wheel 13 is attached to a swing arm 14 and rotates about the axis of rotation 19. The vehicle has a front wheel suspension 15 and also a rear wheel suspension 16. The cyclist feeds his mechanical power into the crank arms 7 via the pedals 6. The human drive power is fed into the bottom bracket circuit 10 via the crank arms 7. Within the bottom bracket circuit 10, the gear ratio, which was selected by the user via a control element 11 on the handlebar 12, is regulated. Additional power is added to the pedaling power exerted by humans within the bottom bracket circuit 10. This additional power is provided by an electric motor. This representation in Figure 1 is only an example. The bottom bracket circuit 10 can be designed with or without an auxiliary drive. The output shaft of the bottom bracket gearshift is coaxial with the bottom bracket shaft and carries the front pulley 8. The front pulley 12 thus forms the transmission output. It rotates at different speeds relative to the crank arms 7, depending on which gear was engaged by the user of the vehicle. In this embodiment, the mechanical power is transmitted to the rear wheel 13 via a belt 12. Optionally, such a transfer of power to the rear wheel 13 can also take place via any other type of transmission. Figure 2 shows a perspective view of the bottom bracket circuit 10 from Figure 1 from the rear left. The pedals 6 and the crank arms 7 are not shown. The frame is cut free and partially shows the down tube 3 and the seat tube 4. At the lower end of the seat tube 4 and the down tube 3 there is a holder 9 into which the bottom bracket circuit 10 is screwed. The swing arm 14 is also cut free. In an advantageous embodiment, the rocker arm 14 is attached to the holder 9 via a rocker arm bearing 17. Anti-squat is a device on wheeled vehicles that is intended to prevent or reduce “diving” when accelerating and thus a pitching movement of the body backwards through the dynamic shift of the wheel load. It is also known as pitch compensation. In order to implement good anti-squat behavior on bicycles, a position of the swingarm bearing 17 near the bottom bracket shaft 18, usually above and slightly behind the bottom bracket shaft 18, is advantageous. In addition, it is advantageous for the geometry and the resulting driving behavior of the bicycle if the distance from the bottom bracket shaft 18 to the axis of rotation of the rear wheel 19 is as small as possible. The output shaft of the bottom bracket gearshift is not visible here on the right side of the vehicle coaxially with the bottom bracket shaft 18 and carries the front pulley 8. The front pulley 12 thus forms the transmission output. The mechanical power is transmitted to the rear wheel via a belt 12. The belt tensioner 20 is attached to the housing 22 of the bottom bracket circuit 10 via fastening plates 21. The tension roller 23 is a component of the belt tensioner 20 and ensures correct belt tension in the belt 12, regardless of the position in which the rear wheel 13 is due to the suspension 16. The bottom bracket circuit has a left protective cap 24, which protects the bottom bracket circuit from environmental influences. Another left protective cap 24 is located in front of the switching shaft, which is not visible here. In an advantageous embodiment, there are fixed bearing axles within the bottom bracket circuit, which are connected to the housing 22 using fastening screws 25. If you look at a vertical plane A, which runs through the axis of rotation of the bottom bracket shaft and is perpendicular to the road, you can see the advantageous design of the new product: All transmission shafts are located in front of this plane, so that there is enough tire clearance and enough space for a technologically sensible position of the Swing arm bearing 17 can be achieved in combination with an advantageous positioning of the sensor arrangement near the bottom bracket shaft. The belt tensioner 20 is constructed in such a way that its tension roller can be located to the right of the tire and its housing can be located in front of the tire.

Figure 3 shows a side view of the bottom bracket circuit 10 from the right. Here too, the illustration shows an example of an advantageous embodiment of the bottom bracket circuit with an integrated electric drive motor and electric switching actuation for bicycles with electric auxiliary drive. The belt 12, the pedals 6 and the crank arms 7 are not shown in this illustration. The bottom bracket circuit 10 in this embodiment can be dismantled into three assemblies, which are accommodated in a common multi-part housing and are described individually in more detail below. The installation space of the respective assembly is outlined in dashed lines in Figure 3. In addition to the individual gear stages, the manual transmission assembly 84 also contains the clutch and the connection to the actuating means as well as the new sensor arrangement with the electronic components that are responsible for determining the torque and the speed on the bottom bracket shaft 18. The axis of rotation X1 of the bottom bracket shaft 18 and the axis of rotation The pulley 8 is screwed to the driver 30 using six fastening screws 82. The driver 30 is connected to the hollow output shaft 36 via a spline 73 and secured axially with the aid of a shaft nut 29. The electric drive assembly 83 is located in front of the manual transmission assembly 84 in the direction of travel. The shaft of the electric motor rotates about the axis of rotation of the electric motor X3. The actuation assembly 85 is arranged below and on the right side of the manual transmission assembly 84 and is pulled up laterally upwards to the right of the shift shaft 67. Within the actuation device 85, which can also be called the actuation assembly 85, there is the stepping gear, superposition gear as well as the electrically operated actuator and an actuator gear and a sensor system. The right gear housing 34 is partially filled with oil to lubricate the gears and is closed by the right side cover 81. The sensors and processing electronics, which determine the speed and position of the electric motor, the actuator motor and the transmission actuation, are located in another chamber that is closed by the right outer cover 86. This exemplary design of the gear housing is particularly space-saving and in this way ensures a narrow Q factor and low weight.

Figure 4 shows a sectional view through the plane that is spanned by the axis of rotation X1 of the bottom bracket shaft 18 and by the axis of rotation X2 of the switching shaft 67. The area of the electric drive assembly 83 is cut away in this illustration and a large area of the actuation assembly 85 is not visible in this illustration. The cranks 7 are attached laterally to teeth on the bottom bracket shaft 18 on both sides. Behind the teeth there are 18 locking rings 33 and a spacer sleeve 28 on both sides of the bottom bracket shaft, which form a stop for the cranks and at the same time the inner ring axially fix the left ball bearing 32. Shaft seals 31 on both sides of the bottom bracket shaft ensure that the oil filling 72 cannot escape from the right and left housing 34,35. In the middle of the bottom bracket shaft there is a spline 73, onto which an axially movable freewheel body 46 is twisted. It has a sawtooth-shaped face toothing on its left side, which is pressed via a spring 50 against a complementary toothing on a fixed freewheel body 46 and engages in a form-fitting manner. The axially fixed freewheel body 47 is part of an input hollow shaft 60, which is rotatably mounted coaxially on the bottom bracket shaft 18 with the aid of plain bearings 48. The input hollow shaft 60 cannot move axially because it is fixed via two retaining rings 33 in. A sensor 59 is arranged on the lateral surface of the input hollow shaft 60. The cyclist's torque is thus directed from the pedals via the cranks 7 into the bottom bracket shaft 18 on both sides and then continued into the input hollow shaft 60. There, a signal with information about the torque can be generated via the sensor 59, which rotates together with the input hollow shaft 60 during operation. Together with the sensor 59, which in an advantageous embodiment is designed as a strain gauge, not only the input hollow shaft 60 rotates, but also a rotating circuit board 44, which is able to further process the information about the torque. Parallel and at a short distance from the rotating circuit board 44 there is a fixed circuit board 45, which in this exemplary embodiment is attached to the right gear housing 34 via a screw connection 50. In an advantageous embodiment, there are also sensors on the rotating circuit board 44 which are able to determine the position, orientation and speed of the input hollow shaft 60 in relation to the gear housing, to the stationary circuit board 45 and, if necessary, to the earth's magnetic field or gravity. According to the prior art, the signal transmission between the rotating and stationary circuit boards 44, 45 can take place wirelessly via radio, for example. Likewise, the energy that is required on the rotating circuit board 44 can be transmitted inductively from the circuit board 45 fixed to the housing. Other types of transmission are also possible. In an advantageous embodiment, the rotating circuit board 44 and the housing-fixed circuit board 45 are located centrally near the bottom bracket shaft 18 exactly between the first gear stage 74, which is located on the left in the direction of travel, and the second gear stage, which is located on the right in the direction of travel. 4, the novel bottom bracket circuit 10 has three drive gears 41, 42 and 43, which are coaxially firmly connected to the input hollow shaft 60. In the embodiment shown, the drive gear 41 has twenty teeth, the drive gear 42 has thirty-two teeth, and the drive gear 43 has 53 teeth. In an advantageous, space- and weight-saving design, these gears are made in one piece and are twisted via a spline 73 the input hollow shaft 60 connected. Axial securing takes place, for example, via a shaft nut 29, which presses the drive gears axially against a shoulder of the input hollow shaft 60. The strength of the drive gear 41 with 20 teeth can be greatly increased if the lateral flanks of this spur toothing are materially connected to the lateral flat surface 76 of the drive gear 42. In this embodiment, the teeth are connected to one another laterally via a web. In addition, a very narrow design is created if the rotating circuit board 49 is attached directly to one of the drive gears 41, 42, 43. If the largest drive gear 43 is located far outside in relation to the input hollow shaft 60, there is enough space for large electronic components 77 that are located on the circuit board 45 fixed to the housing. The teeth of the three drive gears 41, 42, 43 roll with the teeth of the idler gears 51, 52, 53 during operation. The idler gears are arranged coaxially to the switching shaft 67. The axis of rotation X2 of the switching shaft 67 is located at a distance parallel to the axis of rotation The drive gear 42 with 32 teeth is connected to an idler gear 52, which also has 17 teeth. The drive gear 43 with 53 teeth is connected to an idler gear 51, which has 15 teeth. The switching shaft 67 is mounted in the left housing 35 via a ball bearing 28. The ball bearing 28 is axially secured via locking rings 33 and a spacer sleeve 28. In order to ensure assembly capability and tightness, in this embodiment there is a left protective cap 24 on the outside of the left gear housing 35. In an advantageous embodiment, the idler gear with the smallest number of teeth is located at the outer end of the shift shaft 67 near the side wall of the left gear housing 35 and is connected to the largest drive gear. In this way, the shape of the switching shaft 67 can be chosen so that the deflection of the switching shaft 67 due to the radial gearing forces is minimized. This idler gear with the smallest number of teeth has further properties: There is an optional needle bearing 27 between the idler gear 51 and the switching shaft 67. In addition, this idler gear with the smallest number of teeth has an internal toothing 57, which is axially spaced laterally from the running toothing. This structure is advantageous for the service life of the running teeth, since here too the teeth are connected to one another laterally in a materially bonded manner via a ring 78. In this advantageous embodiment, this cohesively connected ring 78 carries an internal toothing 57. A coupling body 58 can positively engage this internal toothing 57 and enable the idler gear 51 to transmit torque to the switching shaft 67. The idler gears 52 and 53 also have internal teeth 57 in the clutch body 58, which are movable on the lateral surface of the switching shaft 67 are embedded, can engage in a form-fitting manner. The coupling bodies 58 are part of the coupling means K1 to K6. As already described above, the coupling bodies 58 are part of the coupling means. If the coupling means K1, K2 or K3 are in an activated state, the idler gears 51, 52, 53 can only transmit torque to the switching shaft 67 in one direction. In order to ensure this function, the coupling means are constructed due to the shape of the internal toothing 57 and with the help of springs (not shown) in such a way that torques can only be positively transmitted in one direction. In the opposite direction, the coupling body 58 slides on the internal teeth 57 and no torque can be transmitted. Likewise, the coupling means K1, K2 or K3 can assume an inactive state. In this state, the coupling bodies 58 are brought into a position with the aid of pivotable supports 61, 62 or 62 and with the aid of springs (not shown) so that the coupling bodies 58 are no longer in connection with the internal teeth 57 of the idler gears. In this inactive state, the respective idler gears can slide quietly on the shift shaft. The following table shows the three possible translations of the first gear stage 74 depending on the state of the clutch means K1, K2 and K3:

Table 1

The table shows that the shift shaft 67 always rotates at least at the same speed as the bottom bracket shaft. This configuration is advantageous in that higher torques are never generated on the shift shaft 67 compared to the bottom bracket shaft. The torques on the switching shaft 67 are even much lower when the clutch means K3 or K2 are activated. The novel switching shaft 67 shown has several non-coaxial bores in which there are several pivotable supports 61-66. The supports are cylindrical components that can pivot about their own axis and are led out of the switching shaft 67 at one axial end. In the embodiment shown, these pivotable supports 61-66 are led out to the right and each have a toothed pinion 79 at their right end, which in turn is connected to the respective internal teeth 71 of two components of a stepping gear 70 is connected. In this embodiment, the axes of rotation of the pivotable supports 61-66 are located in the sectional plane of the illustration in FIG. 4. The pivotable supports can also be located at any other position within the switching shaft 67. The switching shaft is firmly connected to a reference gear 69 on the right side. This reference gear is designed so that it also acts as an axial stop for the inner ring of the ball bearing 32 '. The actuating gear 68 is located on the side directly next to the reference gear 69. Both gears have external teeth. The actuating gear 68 is mounted on the reference gear 69 via a plain bearing 48 and secured axially outwards directly on the right side cover 81. The actuating gear 68, the reference gear 69, the stepping gear 70 with the two associated internal teeth 71 and the six pivotable supports 61, 62, 63, 64, 65, 66 form part of the actuating means. By changing the rotational position of the actuating gear 68 in relation to the reference gear 69, all six supports 61, 62, 63, 64, 65, 66 are pivoted and thus the coupling means K1, K2, K3, K4, K5 and K6 are actuated. Within the second gear stage 75, the idler gear 54, which has 20 teeth, is coupled to the switching shaft 67 via the activated clutch means K4. Likewise, within the second gear stage 75, the idler gear 55, which has 21 teeth, is coupled to the switching shaft via the activated clutch means K5. The coupling means K6 couples the idler gear 56, which also has 21 teeth, to the switching shaft 67 in the same way. The internal toothings 57 are geometrically the same in the first and second gear stages 74,75, but are arranged in mirror images, since in the second gear stage 75 the torques have to be transmitted from the shift shaft 67 to the idler gears 54,55 or 56. In the first gear stage 74, the torques are transmitted from the idler gears 51, 52 and 53 to the shift shaft 67. The output hollow shaft 36 is arranged coaxially to the bottom bracket shaft 18 and, in an advantageous embodiment, is connected in one piece to three output gears. The output gear 37 has 20 teeth, is arranged in the middle of the gear and meshes with the idler gear 54, which also has 20 teeth. The output gear 38 has 32 teeth and meshes with the idler gear 55, which has 21 teeth. The output gear 39 has 26 teeth and is located on the far right on the housing wall of the right gear housing 34. It meshes with the idler gear 56, which has 21 teeth. In general terms, the structure can be summarized as follows: It is a bottom bracket gear 10 with an actuating device, in particular for a vehicle powered by muscle power, with a first sub-gear 74 and a second sub-gear 75 which are connected in series for power transmission, the first Sub-transmission 74 and the second sub-transmission 75 have a switching shaft 67, on which a plurality of idler gears 51-56 are mounted, which are connected to a corresponding plurality of gears 37, 38, 39, 41, 42, 43 pairs of wheels form the respective partial transmission, the idler wheels being connectable to the switching shaft 67 by means of pivoting coupling bodies 61-66. It is clear from the illustration that the novelty is characterized in that the switching shaft 67 has a plurality of axial bores and the several axial bores of the switching shaft 67 are not designed coaxially to the switching shaft 67 and there is a pivotable support 61-66 within each of the axial bores is located and in each case a pivotable support 61-66 is directly or indirectly connected to exactly one coupling body exclusively via its cylindrical lateral surface. The following table shows the three possible gear ratios of the second gear stage 75 depending on the state of the clutch means K4, K5 and K6:

Table 2

Here, too, it is noticeable that the speed from the switching shaft to the hollow output shaft in the second gear stage 75 either remains the same or is reduced. This new design results in good strength in the running gears, because many gears have small numbers of teeth and a large module. The output gears 37, 38 and 39 are connected to the side surfaces of the teeth via webs and are designed in one piece in such a way that excessive tooth root tensions can be prevented. Since the output hollow shaft 36 rotates at different speeds compared to the bottom bracket shaft 18, a double needle bearing 27 is provided. The bearing distance is specified via a spacer sleeve 26. In order to lead the torques out of the bottom bracket gear 10, a driver 30 is attached to the hollow output shaft 36 using a spline 73 and secured axially using a shaft nut 29. This structure also makes sense, as the inner ring of the ball bearing 32” is also fixed in this way. So that no oil can escape from the bottom bracket gear 10, a shaft sealing ring 31 is arranged between the bottom bracket shaft 18 and the output hollow shaft 36. In addition, the shaft seal ring 3T ensures a seal between the driver 30 and the right gear housing 34. The driver 30 transmits the torque to the front pulley 8. Both components are screwed together. This preferred novel design of a Bottom bracket gearshift provides nine gears through the combination of gear stages 74, 75. The following table shows the nine possible gear stages of the bottom bracket gear 10 depending on the state of all clutch means K1 to K6:

Table 3

The entire assembly of the six coupling means K1 to K6 is shown in dashed lines within the illustration in Figure 4 and marked with the reference symbol K.

It can be seen that the exemplary design of the new product provides nine gears with even gradations, all of which are between 23.1 and 23.8%. This gear gradation and the entire range of gear ratios of 538% is a very advantageous design, especially for bicycles with electrical support. The innovation can be used in all e-bike categories, as the driving speed, which also depends on the diameter of the vehicle's driven wheel, can be adjusted using the so-called secondary gear ratio. The secondary gear ratio is the ratio of the number of teeth on the front pulley 10 and the rear pulley, which is usually mounted on the rear wheel 13. The novelty can not only be used on bicycles with electric assistance; this new bottom bracket circuit can also be used on vehicles without an auxiliary drive. The bandwidth of 538% even allows use on a mountain bike. By omitting individual pairs of gears, the new product can also be manufactured more cost-effectively and enable use in categories that require fewer aisles and less bandwidth.

Figure 5 shows a cross section through the plane AB from Figure 4. The bottom bracket shaft 18 rotates about the axis of rotation X1. Visible in this section is the shaft sealing ring 31, which prevents oil from escaping from the left gearbox housing 35. Also visible is the largest drive gear 43, which has 53 teeth. As already explained before, this gear is used exclusively in gears seven, eight and nine for the three fastest or longest gear ratios. According to the advantageous design of the novelty, in order to save weight and installation space, the mechanical power of the auxiliary drive is also fed in via this gear 43. In general terms, at least one gear, which is arranged coaxially to the bottom bracket shaft 18, is constantly connected to two other gears, one of the two gears being a step gear 98. A step gear 98 consists of two gears that have a different number of teeth, are coaxially aligned with one another and are firmly connected to one another. In a preferred embodiment, a step gear 98 is made in one piece. In the embodiment shown, the gear 87, which has 15 teeth, and the gear 88, which has 30 teeth, are designed in one piece as a step gear 98 and rotate about the rotation axis X7. X7 is therefore a rotation axis of the reducer. This step gear 98 is mounted on an axle 99 fixed to the housing with the aid of a ball bearing 32″. In order to make the electric motor used small and light, it is designed for a high speed and this high speed is then reduced to the natural cadence of the human being with the help of a multi-stage reduction gear, which drives the bottom bracket shaft 18 at approx. 50-90 revolutions per minute. reduced. At least one gear of the novelty, which is coaxial with the bottom bracket, is used simultaneously as a component of the reduction gear and as a component of the manual gearbox. In the illustration, this is the gear 43. In order to show the entire reduction gear in FIG. 5, there is an additional section 95 with a view of the first reduction stage. The shaft 100 of the electric motor rotates about the axis of rotation X3 and carries the gear 91 with 12 teeth. The gear runs in the same oil bath as all other gears. Behind the gear 91 there is a shaft seal 31”. It ensures that the rotor and stator with all magnets, windings and also the circuit board of the power electronics with the connection of the individual motor phases 93 are protected from oil in a dry chamber 94. The circuit board with the motor controller is not shown in detail. However, the plug contacts 96 are visible, which are also in the dry area and are connected to the circuit board. The bottom bracket gear, which is often referred to as a drive system when combined with an electric auxiliary drive, is connected via the plug contacts. connected to the control element on the handlebars. The battery, sensors and display elements are also connected to the drive system via these plug connections. The 12-tooth gear 91 is connected to the 55-tooth gear 92. The gear 92 is connected via a freewheel to the gear 90, which has 14 teeth and is designed in one piece as a shaft. This freewheel 97 rotates about the rotation axis X5 and ensures that the cyclist does not have to drag the electric motor along empty or even operate it as a generator when the auxiliary drive is switched off. The gear 89 has 21 teeth, rotates about the rotation axis X6 and establishes a connection between the gear 90 and the gear 88. The following table shows the gear ratios of the individual reduction stages and their rotation axes:

Table 4

The entire reduction gear is advantageously constructed in such a way that the engine speed at the shaft 100 up to the bottom bracket shaft 18 is reduced by a factor of 34.7. The size of the gear 89 has no influence on this overall ratio. However, this gear 89 bridges the distance to the neighboring gear stage within the novelty.

Figure 6 shows a perspective view of the bottom bracket circuit 10 from Figure 2. It shows the structure of the novel bottom bracket circuit 10 with an electric auxiliary drive in an advantageous embodiment. The electrical actuation is not visible in this view. The left and right housing, the side covers, all screws, the pedal cranks 7, the front pulley 8, the plug contacts, the circuit board with the power electronics are not shown. This is an exemplary representation of the bottom bracket gear, in particular for a muscle-powered vehicle with an additional electric drive, with a first sub-gear 74 and a second sub-gear 75, which are connected in series for power transmission, the first Sub-transmission 74 and the second sub-transmission 75 have a switching shaft 67, on which a plurality of idler gears 51, 52, 53, 54, 55, 56 are mounted, which are connected to a corresponding plurality of gears 43, 42, 41, 37, 38, 39 Wheel pairs of the respective partial transmission form, the idler wheels being connectable to the switching shaft 67 by means of coupling bodies. In addition, the advantageous embodiment is characterized in that the smallest idler gear 51 forms a pair of wheels with the largest drive gear 43 and is arranged laterally on the left in the direction of travel and that the largest drive gear 43 is also in a force-transmitting connection with a further gear 87, this further gear 87 is in direct or indirect connection to the shaft 100 of the additional electric drive 102. In an advantageous embodiment, this additional gear 87 is located near or directly below the smallest idler gear 51. If you look at the cylindrical volume that encloses the largest drive gear 43, the left ball bearing of the bottom bracket shaft is also located in this volume. In this advantageous structure shown, the largest drive gear 43 has a bell-like shape and is materially connected to two further drive gears 41 and 42. In addition, the three output gears 37, 38 and 39 are also materially connected to one another. Since this structure is very space-saving, in this advantageous embodiment two circuit boards 44, 45 with electronic components can be placed in the frame of the sensor arrangement coaxially and centrally to the bottom bracket shaft 18 between the first and second partial gears 74, 75, one circuit board 44 with the same Speed rotates, as the bottom bracket shaft 18 and the second circuit board 45 cannot move relative to the housing, both circuit boards being arranged directly next to one another, exchanging electrical signals with one another and at least one signal being generated on one of the two circuit boards, which is representative of the torque of the cyclist. In addition, it is advantageous if the circuit board, which is stationary relative to the housing, has attachment points 103 which are connected to the housing and the circuit board, which rotates at the same speed as the bottom bracket shaft, has attachment points which are connected to one of the three drive gears 41 , 42, 43 are connected. In a further advantageous embodiment, the electric additional drive 102 with the rotor and stator is preferably located in front of the second partial gear 75 in the direction of travel, so that the space on the left side in the direction of travel can be used for the necessary gear stages 91, 92, 90, 89, 87, which reduce the speed of the electric motor 102. In an advantageous embodiment, the pairs of gears that reduce the speed of the electric drive motor 102 are located in front of and below the first partial transmission in the direction of travel. More generally, the axes of rotation X5,X6,X7 of the reduction gear stages and the axis of rotation of the electric motor Located in an advantageous embodiment The circuit board 104, which electronically determines the position or orientation of the rotor of the electric motor 102, is to the right of the electric motor 102 in the direction of travel. In this way, this circuit board 104 can be accommodated in a dry installation space and the gear 91, which is on the motor shaft 100 can run in an oil bath. The reaction forces of the gear 91 can be easily absorbed by a needle bearing 27 and the electric motor 102 can be well sealed from the oil bath with a shaft seal 31. It can also be seen in Figure 6 that the idler gears have running teeth on their lateral surface, with the side surfaces of the teeth of at least one idler gear 51 being connected to one another on one side via a web 101. This shape is very advantageous for the durability of the gearing. In other words, the novelty is characterized by the fact that axially next to the idler gear 51 there is a cylindrical disk or a ring 78, which is cohesively connected to the gear and has at least a diameter that is larger than the root circle of the idler gear 51. Axial to the side Next to the cylindrical disk there is also a materially connected coupling toothing, which is designed as an internal toothing and can be connected to the coupling body. The idler gear 51, the cylindrical disk and the clutch teeth are designed in one piece or are joined in a materially bonded manner.

Figure 7 shows a perspective view of the assembly of the switching shaft 67. The components that are arranged on the switching shaft 67 are shown in a sectional view. In this advantageous exemplary embodiment, the switching shaft has a smaller diameter on the left side than in the middle of the shaft. On the left side, the switching shaft 67 is mounted in the housing, not shown, via a ball bearing 32. The ball bearing 32 is axially attached to the shaft collar 105 via a spring ring 33 and a spacer sleeve 28. The switching shaft also has a smaller diameter on the left side compared to the middle of the shaft because the idler gear 51 only has 15 teeth and this results in a small diameter. It can be seen in the illustration that the idler gears 51, 52, 53, 54, 55, 56 can be connected to the switching shaft 62 by means of coupling bodies 58. This preferred embodiment is characterized in that these six coupling bodies 58 can form a positive connection with the matching internal teeth. In Figure 7, only two coupling bodies 58 are visible. However, each of the idler gears 51, 52, 53, 54, 55, 56 each has an internal toothing 57. The novelty in this advantageous embodiment is characterized in that on at least one idler gear 51, the internal toothing 57 is laterally spaced apart from the external toothing. This embodiment also shows that each coupling body 58 is connected to a worm spring 106. Each worm spring 106 is located in a groove 107, which is located on the lateral surface of the switching shaft 67. There are in the representation six worm springs 107, which ensure the correct function of the coupling bodies 58. Since the idler gears 51, 52, 53, 54, 55, 56 run in an oil bath and are therefore well-sliding relative to one another axially and radially to the switching shaft 67, they can assume different speeds relative to one another without major friction losses. The axial bearing play can be adjusted by correctly selecting the thickness of a sliding disk 108. On the right side, the switching shaft 67 is also mounted in the right gear housing 34 via a ball bearing 32 '. The ball bearing 32' is supported axially on a further collar 105' and on the reference gear 69 of the switching shaft. The reference gear 69 is attached to the switching shaft 67 and rotates at the same speed during operation. Next to the reference gear 69 is the actuating gear 68 of the switching shaft 67. The switching process is carried out by rotating this actuating gear 68 in relation to the reference gear 69. By rotating this actuating gear 68, which also has internal teeth 71, three of the six illustrated pivoting supports 61, 62, 63, 64, 65, 66 are rotated directly within the bores that are located on the right plan side of the switching shaft 67. Of these pivotable supports 61, 62, 63, 64, 65, 66, only the toothings at the ends can be seen in FIG. 7 and are not labeled with reference numbers for better visibility. In different rotationally adjustable positions of the pivotable supports 61, 62, 63, 64, 65, 66, the coupling bodies 58, which are located within a recess 107 on the lateral surface of the switching shaft, can assume different states. The remaining three of the six pivoting supports 61, 62, 63, 64, 65, 66 shown are only rotated at certain times within the bores of the switching shaft 67, since they are connected to the actuating gear 68 via a stepper gear 70. This embodiment has the advantage that a rotation of, for example, 40 degrees on the actuating gear 68 causes a rotation of, for example, 120 degrees on the respective pivotable supports 61, 62, 63, 64, 65, 66. The nine gear stages shown above are thus switched through with the help of a rotary movement of 8 times 40 degrees on the actuating gear 68. This corresponds to a rotation of 320 degrees. The useful new gear ratios listed above can be easily implemented within the scope of the embodiment shown if the gear unit is characterized in that the root diameter of the external toothing of the idler gear 51, which has an internal toothing 57 that is laterally spaced, is characterized in that the root diameter is smaller or is equal to the maximum diameter of the internal teeth. This design can even be improved in terms of strength if the novelty is characterized in that at least this one idler gear 51, which has internal teeth that are laterally spaced, is characterized in that the teeth of the external Teeth, which represents the running teeth, are laterally materially connected to each other. In parallel, there is also further reinforcement if at least the idler gear 51, which has an internal toothing 57 that is laterally spaced, is characterized in that the teeth of the internal toothing 57 are materially connected to one another laterally. It is clear from the illustration that the switching shaft 67 in the area in which it is connected to the idler gear 51, which has internal teeth 57 that are laterally spaced, is characterized by the fact that the switching shaft 67 has two different outer diameters in this area owns. Here, the larger outer diameter is preferably located within the clutch teeth 57. The idler gear 51, which has an internal toothing 57 that is laterally spaced, is preferably in engagement with the largest gear or drive gear 43, which is coaxial with the bottom bracket shaft 18. The plane E1 is perpendicular to the axis of rotation of the switching shaft 67 and is located in the middle of the idler gear 56.

Figure 8a, Figure 8b and Figure 8c each show a section through the plane E1 of the idler gear 56 of the bottom bracket circuit in the view from the left. In all figures, the gearbox housing is not shown on the right. Also visible in all figures is the coupling means K6, consisting of the internal toothing 57, the coupling body 58, the worm spring 106 and the pivotable supports 61, 62, 63, 64, 65, 66. It is clear from the illustration that only the one is pivotable Support 66 for which a clutch body 58 is responsible. Preferably, none of the bores in which the pivotable supports 61, 62, 63, 64, 65, 66 are arranged are located concentrically to the switching shaft 67. In a preferred embodiment, the novel bottom bracket circuit is designed in such a way that the bores in which the pivotable Supports 61, 62, 63, 64, 65, 66 are arranged at the same distance from the lateral surface of the switching shaft 67, each hole also being at the same distance from the two adjacent holes. In a preferred embodiment, the coupling body 58 is provided with a slot so that the worm spring 106 can apply a defined force to the coupling body 58. Worm feathers are subjected to tension and can be connected at the ends to form a ring shape. By subsequently joining them together, the worm spring is often used within shaft seals and is therefore an industrially produced and cost-effective machine element. Figure 8a shows the clutch body 58 completely submerged within the pocket, which is milled as a recess on the lateral surface of the switching shaft 67. The coupling body 58 is not connected to the internal toothing 57 of the idler gear 56. The idler gear 56 can rotate freely in both directions of rotation. The coupling means is deactivated in both directions of rotation. The pivoting support 66 is not in direct contact with the coupling body. Figure 8b shows the coupling body 58 completely inserted into the internal teeth 57 of the ring gear coupled. The coupling agent is activated. The cylindrical lateral surface of the pivotable support 66 is in a force-transmitting connection with the clutch body 58. In this state, the switching shaft can transmit a torque to the idler gear 56 in a clockwise direction. Figure 8c shows the state when the idler gear 56 rotates clockwise faster than the switching shaft 67 when the clutch means is activated. In this state, the back of the clutch body 58 slides over the internal teeth 57. This state can occur briefly during the switching process.

Figure 9a, Figure 9b and Figure 9c show the detail A1 from the sectional view of Figure 8 in a schematic representation in general for such a coupling means K according to the novelty. The switching shaft 67 rotates about the rotation axis X2. In this exemplary representation, the idler gear 109 rotates counterclockwise and drives the switching shaft 67. The internal toothing 57 is located concentrically in the idler gear 109. It has bearing surfaces 112, pressure surfaces 110 and sliding surfaces 111. The switching shaft 67 preferably has three or more than three axial bores 113, which are arranged parallel or almost parallel to the axis X2 of the switching shaft 67. Figure 9a, Figure 9b and Figure 9c show representatively and schematically only one of these axial bores 113. The pivotable support 114 is located in the bore 113. The pivotable support 114 can, as shown in Figures 9a and 9b, assume a first state, in in which the pivotable support is directly connected to exactly one coupling body 58. In this first state, the coupling means is activated and it can also be seen that the coupling body 58 can be brought into a force-transmitting connection to the idler gear 109. The force-transmitting connection to the idler gear 109 is achieved when the idler gear 109 rotates counterclockwise as shown in Figure 9a and drives the switching shaft 67. The force-transmitting connection to the idler gear 109 is not achieved if the idler gear 109, as shown in Figure 9b, rotates clockwise and cannot drive the switching shaft 67, since the coupling body 58 cannot form a positive connection with the pressure surface of the internal toothing 110. If the idler gear 109 rotates clockwise, as shown in Figure 9b, the coupling body 58 slides, among other things, against the sliding surfaces of the internal toothing 111 and no torque can be transmitted from the idler gear 109 to the shaft 67. Within this preferred exemplary embodiment, the coupling body 58 has a spring mounting surface 117 which is constantly in contact with a spring 118, for example a worm spring 106, and ensures that the coupling body 58 can assume different states and does not move erroneously between the Internal teeth 57 and the switching shaft 67 can jam. So does the worm feather 106 cannot jam during operation between the switching shaft 67, the coupling body 58 and the internal toothing 57 of the idler gear 108, the switching shaft preferably has several grooves on its cylindrical lateral surface in which the almost annular spiral springs, also called worm springs 106, are inserted. For the same reason, the coupling body 58 has a groove in which the almost annular spiral springs, also called worm springs 106, are inserted. The above-mentioned spring fastening surface 117 is located within this groove.

If you look at Figure 9c, you can see that the pivotable support 114 can assume a second state in which the pivotable support 114 is not connected to the coupling body 114. In this second state, this clutch body 114 cannot be brought into a force-transmitting connection to the idler gear 109 and, regardless of the direction of rotation of the idler gear 109, no surface of the internal toothing 57 can come into connection with the clutch body 58. The idler gear 109 can slide on the switching shaft 67 without making any noise. The coupling means is shown deactivated in Figure 9c. 9 also shows that the recess 107, in which a coupling body 58 is located, is connected to the bore 113 via an opening 119, in each of which there is a pivotable support 114.

Figure 10a shows the coupling means according to the novelty in a detail from Figure 9a in a schematic representation. The idler gear 109 and the switching shaft 67 are only shown in a section and are able to rotate about the rotation axis X2. The idler gear 109 has internal teeth 57 which are arranged symmetrically and concentrically in the idler gear 109. The internal toothing 57 has pressure surfaces 110 which transmit the forces from the idler gear 109 to the pressure surfaces 116 of the clutch body 58. In a preferred embodiment, the pressure surfaces 116 and the pressure surfaces 110 are both slightly curved in the same direction. The force arrow Fk 124 represents these forces in the illustration. This type of arrangement is of course also able to transfer the forces in reverse from the clutch body to the idler gear 109. However, in order to describe the preferred principle, the following description selects the case in which the forces from the idler gear 109 are transmitted to the clutch body 58 on the clutch body 58. The clutch body 58 is located on the switching shaft 67 within a pocket 107, which can also be described as a recess within the lateral surface of the switching shaft 67. The clutch body 58 is mounted on surface 137 on the switching shaft 67 and can therefore rotate about the rotation axis X8. The force Fk 124, which is applied to the clutch body 58 by the idler gear 109, is derived from the support force Fa 140 into the switching shaft 67. However, since the force Fk 124, which is introduced into the clutch body 58 by the idler gear 109, has a lever arm Ik with respect to the axis of rotation X8, a torque also arises and the clutch body 58 wants to rotate clockwise around the axis Rotate X8. However, this rotational movement due to a torque MA is prevented because the pivotable support 114, which is arranged within an axial bore 113 in the switching shaft 67, supports the clutch body 58 with the force Fb 125. An equilibrium of torques about axis X8 occurs:

FK* IK = FB * IB = MA

The lever arm Ik should preferably be made short and the lever arm Ib somewhat longer, since this allows the support force Fb on the pivotable support 114 to be minimized. As part of the novelty, it is therefore a self-disengaging clutch body 58. The shape of the clutch body 58 and the internal toothing 57 are selected so that the torque Ma when the support 114 is pivoted out, the static friction between the pressure surface 116 of the clutch body 58 and the pressure surface 110 of the internal toothing 57 overcomes and deactivates the coupling agent. The mechanical work to overcome the static friction is therefore carried out by the cyclist himself. The actuating means must only use mechanical work to move the pivoting support. The friction on the pivoting support is determined exclusively by the force Fb, which was minimized as part of the advantageous design of the coupling body. The torque Mb 126 is easily applied to the pivoting support 114 by an actuating means since the pivoting support 114 rotates about its own axis X9. In an advantageous embodiment, the pivotable supports 114 have a cylindrical shape, with the diameter of the cylinder being at least a factor of three smaller than the diameter of the switching shaft. A cylinder that is to be pivoted through a certain angle within a bore under radial load can be pivoted more easily the smaller its diameter. In an advantageous embodiment, the bearing surface 139 of the pivotable support 114 on the switching shaft 67 and the surface within the axial bore 113 of the switching shaft 67 are made of steel and are hardened. If the axial bore 113 is connected to the recess 107 in the lateral surface of the switching shaft 67 only via a single opening 119, the strength of the switching shaft 67 is maintained, since the switching shaft 67 is not, as is usually the case in designs according to the prior art, is weakened by a large concentric bore.

In comparison to Figure 10a described above, Figure 10b shows the coupling means according to the prior art in a comparable schematic representation. The force Fk 124, which is transmitted from the idler gear 109 via the pressure surface 110 of the internal toothing 57 to the clutch body 58, ensures a counterclockwise torque Mp about the axis of rotation X8. In this embodiment according to the prior art, this torque Mp leads to self-locking. The clutch body 58 transmits the forces completely and exclusively via the bearing surface 137 of the clutch body on the switching shaft 67. The torque Mp ensures that the clutch body is supported on the internal toothing 57 with the force Fr. In order to initiate a switching process according to this prior art, the frictional force that arises due to the surface pressure on the pressure surface 116 of the clutch body must be applied entirely by the impressed force Far 136 of the camshaft 138. Due to the relatively long lever arm Ln 134 on the camshaft 138, which according to the prior art is usually attached coaxially to the switching shaft 67, the torques Mn introduced by the actuating means must be very high in order to release the clutch body 58 from the internal toothing 57. With the same force Fk, the actuation torque Mb in the novel embodiment according to FIG. 10a is significantly lower than the actuation torque Mn in embodiments according to the prior art according to FIG. 10b. This shows that the novel design of the switching device within the bottom bracket circuit can also carry out a switching process under load.

Looking at Figure 10a, one can summarize that an exemplary preferred bottom bracket gear with a switching device is characterized in that idler gears have concentric bores and the bores are designed with internal teeth 57 and the switching shaft 67 and the coupling bodies 58 and at least part of the pivotable supports 114 are located and the internal toothings 57 have pressure surfaces 110 which transmit the forces from the idler gear 109 to the pressure surfaces 116 of the clutch body 58 and the pressure surfaces 116 of the clutch body 58 and the pressure surfaces 110 of the internal toothing 57 are both the same direction are slightly curved. In addition, this exemplary embodiment is characterized in that the clutch body can assume a state in which the force that is transmitted from an idler gear to this clutch body can be simultaneously conducted from the clutch body into the shift shaft and into a support and wherein the support is in relation its position and orientation relative to the switching shaft can be changed via an actuating means.

Figure 11a shows the switching shaft 67 from Figure 7 in a perspective view without the idler gears 51 to 56. The right housing 34 and the left housing 35 are also not shown. The representation is exemplary. On the left side there is the ball bearing 32, which has a Circlip 33 is axially fixed. To the right of the ball bearing 32 there is a spacer sleeve 28. The idler gears are supported axially to the left against this spacer sleeve 28 and to the right against the shaft collar 120”. The switching shaft 67 has several grooves 142 on its cylindrical lateral surface, in which almost annular spiral springs 106 can be inserted. The annular spiral springs 106 are not shown in Figure 11a. In this embodiment, the switching shaft 67 has six chambers 143 in its interior, which are arranged parallel or almost parallel to the axis of the switching shaft. These chambers are not designed to be coaxial with the axis of rotation X2 of the switching shaft 67. There is a pivoting support 61-66 within each of the six chambers. Each pivotable support 61-66 can assume a first state in which the pivotable support 61-66 is directly or indirectly connected to exactly one coupling body 144-149. It can be seen that the clutch body 149 is folded up and so in this first state this clutch body 149 is in a force-transmitting connection to the idler gear 56, not shown. It can also be seen in the illustration that the lateral surface of the switching shaft 67 has recesses 107 in which the coupling bodies 144-149 are located. Only three coupling bodies 142, 146 and 149 are visible in Figure 11a. The plurality of depressions 107 are preferably evenly distributed over the circumference of the lateral surface. So that the coupling bodies can be controlled, the six recesses 107 are each connected via an opening 119 to the six chambers in which the pivotable supports 61-66 are located. The ball bearing 32' is located on the right side. The ball bearing 32' is fixed axially via the reference gear 69. The actuating gear 68 is located on the far right of the switching shaft 67 and is able to operate the six pivoting supports 61-66.

11b shows the assembly from FIG in which the two supports 61 and 66 are directly connected to exactly one coupling body 144 and 149. In this state, the coupling bodies are folded up and can transmit forces. The coupling means K1 and K6 are activated. This first state corresponds to the principle which was described in the illustration in FIG. 9a. The four pivoting supports 62, 63, 64, 65 are in a second state in which each of the four pivoting supports 62, 63, 64, 65 is not connected to one of the respective coupling bodies. This decoupling is possible because the pivotable supports 61, 62, 63, 64, 65, 66 have a cylindrical shape and have recesses 150 on the cylindrical lateral surface 151 have, and wherein the recesses 150 are located near the coupling bodies 141-146. In this second state, the coupling bodies are folded down and cannot transmit any forces. The coupling means K2, K3, K4 and K5 are deactivated. This second state corresponds to the principle which was described in the illustration in FIG. 9c. In this second state, this clutch body cannot be brought into a force-transmitting connection to an idler gear. The pivoting supports 61-66 have different lengths and are located within the switching shaft 67 in a chamber with a cylindrical shape. This shape can preferably be implemented in production using axial bores of different depths.

In this representation of the switching shaft of the new bottom bracket gearbox it is also clear that a first sub-gearbox and a second sub-gearbox are connected in series for power transmission: The clutch bodies 144, 145 and 146 transmit torques from the idler gears 51, 52 and 53 to the idler gears 51, 52 and 53 within the first sub-gearbox Switching shaft 67. The clutch bodies 147, 148 and 149 are rotated by 180 degrees within the switching shaft 67 and are part of the second partial transmission. In order to transmit torque via both partial transmissions, one of the three clutch bodies 144, 145, 146 and one of the three clutch bodies 147, 148, 149 must be folded up. Each sub-transmission has three gears. The series connection of the partial transmissions results in 9 gears. To change gears from one gear to the next gear, the three pivoting supports 61-63 or 64-66 in the partial transmission rotate simultaneously around their own axis of their cylindrical shape by 120 degrees. The recesses 150 on the cylindrical lateral surfaces of the pivotable supports must therefore extend over a range of 240 degrees in this exemplary embodiment, since only a single gear in the partial transmission may be activated over a 360 degree pivoting movement.

11 b also shows that it is advantageous for the strength of the switching shaft 67 if the axial bores in which the pivotable supports 61-66 are arranged are at the same or similar distance from the lateral surface of the switching shaft 67. In this case, the shape of the coupling bodies 144-149 is also the same. If each hole is at the same or similar distance from the two adjacent holes, a good voltage curve can be achieved within the switching shaft. The coupling bodies 144-149 have a groove as a spring support surface 117, with the worm spring 106 within the groove ensuring that the functions of the coupling bodies 144-149 are achieved as described above. The pivoting supports 61-66 are led out laterally from the switching shaft 67 and are provided with gears 152, 153, 154, 155, 156, 157 at their end. Instead of gears, the pivoting supports 61-66 can also be provided with other gear elements for control. The exemplary embodiment has six pivoting supports 61-66 with six actuating gears 152-157. The gears are not in the same plane. Three gears 152, 153, 154 and 155, 156, 157 are located in one plane. The exact gears that are connected to the pivoting supports and which are responsible for the first or second gear stage must be in one plane. In the advantageous embodiment, the actuating gears 152, 153, 154 for the first sub-transmission are located in one plane and the actuating gears 155, 156, 157 for the second sub-transmission are in a second level. This circumstance is shown in Figure 11d. Figure 11d shows an enlargement of the right area from Figure 11c. Each gear 152-157 has 13 teeth. The gears 152, 153, 154, which are responsible for the coupling means K4, K5, K6, are located on the outside. The gears 155, 156, 157, which are responsible for the clutch bodies K1, K2, K3, are slightly offset to the inside. The gears are preferably made in one piece with the pivoting supports 61-66. However, an embodiment is also possible in which the gears 152-157 are attached and fastened. So that the angular position of the pivotable supports 61-66 can be locked in an advantageous manner, the pivotable supports 61-66 have three depressions 158 on their lateral surface at a distance of 120 degrees into which a resilient pressure piece 80 can engage. The resilient pressure pieces 159 are screwed into the switching shaft 67 at the right end below the bearing seat of the ball bearing 32 '. A resilient pressure piece 80 is assigned to each pivotable support 61-66. Each pivoting support 61-66 can lock into three positions after being operated from the outside. The actuation should be designed so that each pivoting support 61-66 is always rotated exactly 120 degrees in this preferred embodiment for switching from one gear to the next gear. Each individual pivoting support has two locking points at which the coupling means is deactivated. Each pivotable support has another locking point at which the coupling means is activated. If you look at Table 3 listed above in the text, it becomes clear that the pivoting supports of the clutch means K1, K2 and K3 only have to be moved between third and fourth gear and between 6 and 7 gear. In this preferred embodiment, the pivoting supports of the first sub-transmission are only moved at two times simultaneously together with the pivoting supports of the second sub-transmission, so that the gears from one to nine can be shifted through. Figure 12a shows a section on the right side of the bottom bracket shaft in a view from above. Only the bottom bracket shaft 67 with the right gear housing 34, the idler gear 56 and the idler gear 55 are visible. Also visible is the actuation gear 68 and the reference gear 69. The novel bottom bracket gear is preferably characterized in that a reference gear 69 is firmly connected to the side of the switching shaft 67 and an actuation gear 68 is in turn located laterally next to the reference gear. In a preferred embodiment, these two gears have external teeth with the same diameter, the diameter being larger than the outside diameter of the switching shaft and the actuating gear 68 being connected to at least part of the pivotable supports via one or more gear elements and the actuating gear 68 being on the reference gear 69 is stored. A switching process during operation of the bottom bracket shifter is carried out by moving the actuating gear 68 about the axis X2 relative to the reference gear 69.

Figure 12b shows the section CD through the actuating gear 68 from Figure 12a. In this advantageous embodiment, the actuating gear 68 has an internal toothing 71 in addition to the external toothing, the internal toothing 71 being connected to three toothed pinions 79, these toothed pinions 79 being connected to the pivotable supports 64, 65 and 66. The actuating gear 68 is therefore indirectly connected to the pivotable supports of the clutch means K4, K5 and K6, since these clutch means have to be changed with every gear change according to Table 3 above. In this advantageous embodiment, the actuating gear 68 controls the gears 155, 156 and 157, since these are responsible for the coupling means K4, K5 and K6. 12b also shows that the axial bores, in which the pivotable supports 64, 65 and 66 with the gears 155, 156 and 157 attached thereto are arranged, are evenly spaced on a pitch circle on the lateral axial flat surface of the switching shaft and wherein the pitch circle is arranged concentrically to the axis of rotation X2 of the switching shaft 67.

Figure 13a shows a section on the right side of the bottom bracket shaft in a view from above. The bottom bracket shaft 67 is covered by the ball bearing 32' in the view. The gear housing 34, the idler gear 56 and the idler gear 55 from Figure 12a are not shown. Also visible is reference gear 69, which has a short cylindrical ring 159 on its right plan side on which the actuating gear 68 is mounted.

Figure 13b shows the section EF through the reference gear 69 in Figure 13a at the level of the middle of the short cylindrical ring 159. The section shows a stepper gear, which allows the gears 152, 153, 154, which are responsible for the actuation of the clutch means K1, K2, K3, to be moved only in the periods when the actuating gear 58 is shifted from third to fourth and from sixth to seventh gear. The reference gear 69 is made in one piece together with a short cylindrical hollow shaft stub 159. The actuation gear 68 also has a short cylindrical ring 161 which is mounted in the ring 159. This ring 159 has a groove 162 in which a ball 165 is movably inserted. The actuating gear 68 forms with its ring 161 the input of the stepper gear 160. When the actuating gear 68 rotates, the ball 168 is radially displaced by a link 166 on the inner ring surface of the ring 159 at certain angular transitions and can the internal ring gear 164, which is for the actuation the coupling means K1, K2, K3 is responsible. In a preferred embodiment, the ring gears 164 and 71 have 39 teeth. The ring gear 164 forms the output of the stepping gear 160, since this ring gear 164 only moves step by step. A rotation of the ring gear 164 by 40 degrees causes the gears 152, 153, 154 to rotate by 120 degrees, since these gears preferably have 13 teeth. As already described above, it is therefore possible to put the clutch means into two deactivated and one activated states within one revolution of the pivoting supports and to achieve the 9 gear stages according to Table 3. Figure 13b shows the novelty as an example in the first of 9 gears. The angular movement that must be carried out on the ring 161 in order to select nine gear steps consists of eight individual movements of 40 degrees each, which are shown with the help of arrows within Figure 13b. The nine gear levels are marked with Roman numerals. The illustration shows the ball 165 in the first gear position, marked I. To engage the second gear, the ball 165 is rotated counterclockwise about the axis X2 using the ring 61 until the ball has reached position II. To engage third gear, the ball 165 is rotated counterclockwise around the axis X2 using the ring 61 until the ball has reached position III. To shift from third gear to fourth gear, the ball 165 is rotated counterclockwise about the axis X2 by an additional 40 degrees using the ring 61 until the ball has reached position IV. During this movement, the ball is pressed inwards by the ring 159 and engages within a groove 167 on the ring gear 164 and takes the ring gear with it in the counterclockwise rotation. In this area between position III and position IV, the ring 159, which works as a frame within this stepper gear 160, has no internal milling on its link 166. For this reason, the ball moves on an inner diameter 168. In this area between position III and position IV, the three gears 152, 153, 154 are simultaneously rotated by 120 degrees by the ring gear 164. To shift from fourth gear to fifth gear, the ball 165 is further rotated counterclockwise by another 40 degrees using ring 61 until the ball has reached position V. In this area, the three gears 152, 153, 154 are no longer rotated by the ring gear 164 because the ball 165 cannot take the ring gear 164 with it. The ball 165 is located on its outer barrel diameter 169. It also remains there when switching from fifth gear to sixth gear and the ball 165 continues to rotate counterclockwise with the help of the ring 61 until the ball has reached position VI. In order to shift from sixth to seventh gear, the process that already took place from third to fourth gear is repeated. The ball 165 is pushed inwards by the link of the outer ring 159 within the groove 162 and snaps into a recess 167. In a preferred embodiment, the recess 167 is made as a groove 167 and is located on the ring gear 164. The ring gear 164 is rotated from position VI to position VII together with the actuating gear 68, which is connected in one piece to the ring 161. To shift from seventh gear to eighth gear, ball 165 is rotated counterclockwise about axis X2 by another 40 degrees using ring 61 until the ball reaches position VIII. In this area, the ring gear 164 is again not rotated. The ball 165 slides within the link 166, which is located as a milling on the inside of the ring 161. To shift from the eighth gear to the ninth gear, the ball 165 is rotated counterclockwise by a further 40 degrees about the axis X2 using the ring 61 until the ball has reached position IX. Even during this movement, only the pivotable supports 64, 65, 66 in the axial bores are rotated by the actuating gear 68. The pivotable supports 61, 62, 63, which are connected to the gears 152, 153, 154, are not rotated during this movement. This stepping gear 160 in this preferred embodiment moves exclusively in a range of 320 degrees. A complete rotation is not desired in this exemplary embodiment. The movement can be clockwise or counterclockwise. A clockwise rotation corresponds to shifting from a high gear to a lower gear. The functionality works in both directions of rotation. 13b also shows that the axial bores in which the pivotable supports are arranged are evenly spaced on a pitch circle on the lateral axial flat surface of the switching shaft and the pitch circle is arranged concentrically to the axis of rotation X2 of the switching shaft 67.

Figure 14 shows a schematic representation of the stepping gear 160 coupled to the switching shaft 67 in connection with the actuation assembly 85. All actuation means are located within the actuation assembly 85. Within the representation is still the right part of the switching shaft 67 and the right ball bearing 32 'shown cut off. As already explained above, the state of the three clutch means K1, K2 and K3 is only changed between the third and fourth gear and between the sixth and seventh gear via the stepping gear 160. On the one hand, the actuating gear 68 actuates the coupling means K4, K5, K6 directly and the coupling means K1, K2, K3 via the ring gear 164. When the cyclist pedals while driving, the bottom bracket shaft 67 constantly rotates about the axis of rotation X2. If no switching movement is carried out during this journey, the entire stepping gear 160 with the reference gear 69 and the actuating gear 68 rotates at the same speed as the switching shaft 67. In an advantageous embodiment, the axis of rotation X2 of the switching shaft 67 is coaxial with the axis of rotation X11 of the stepping gear 160 and that Stepper gear 160 is located at least to a large extent laterally next to the switching shaft 67 and next to the ball bearing 32 'of the switching shaft 67. Here, the switching shaft 67 is preferably connected to a reference gear 69 with external teeth, which has a larger diameter compared to the outer diameter of the switching shaft 67 and wherein the stepping gear 160 has an actuating gear 68 with external teeth that have a similar or the same diameter compared to the reference gear 69. As already described above, the switching process is initiated by rotating the actuation gear relative to the reference gear 69. This switching process must also work when the switching shaft is rotating. With the help of the superposition gear 170, which is located parallel and not coaxial to the switching shaft, the actuating gear 68 can be rotated in relation to the reference gear 69 from a stationary housing 121.

The superposition gear 170 according to the novelty has a sun gear 173, this sun gear 173 being arranged in a twisted manner on a housing 180. This connection can also be made indirectly. An actuating sun gear 174 is mounted in the housing 180 coaxially with this fixed sun gear 173. Both sun gears 173, 174 are in engagement with planetary gears 176. Both sun gears 173, 174 preferably have the same diameter and, in a preferred embodiment, all planetary gears 176, 176', 176", 176"' also have the same diameter. The planetary gears 176, 176', 176", 176'" are mounted on the web 175 via planetary gear axles 179. The planet gears 176, 176', 176", 176'" are preferably in contact with two internal toothings 182,182'. In an advantageous embodiment, the first internal toothing 182 is located within a concentric bore of an externally toothed reference wheel 177 of the superposition gear. In an advantageous embodiment, the second internal toothing 182 'is located within a concentric bore with an externally toothed actuator. transmission wheel 178 of the superposition gear. The actuating wheel 178 of the superposition gear 170 is constantly in engagement with the actuation gear 68 of the stepper gear 160. The reference wheel 177 of the superposition gear 170 is constantly in engagement with the reference gear 69 of the stepper gear 160. When the cyclist pedals while driving, the bottom bracket shaft rotates 67 constantly around the rotation axis X2. If no switching movement is carried out during this journey, the entire stepping gear 160 with the reference gear 69 and the actuating gear 68 rotates at the same speed as the switching shaft 67. Consequently, the reference gear 177 of the superposition gear 170 and the actuation wheel 178 of the superposition gear 170 also rotate during operation constant. Since the sun gear 173 is fixed to the housing, the web also rotates about the axis X10. The actuation sun gear 174 stands still in relation to the housing 180 during operation. If an actuation torque MBT is introduced at an actuation interface 181, this rotational movement leads to a relative rotation of the actuation gear 68 in relation to the reference gear 69. The actuation is also possible while the Switching shaft 67 rotates. The torque flow that occurs during operation of the manual transmission is shown schematically in FIG. 14 as a thick black line. In this exemplary embodiment, an electric servomotor 183 is arranged on the actuation interface 181 via a reduction gear 184. In this way, high torques can be fed into the actuation interface 181 to enable shifting under load on the bottom bracket gear. If one considers the entire actuation assembly 85 within the novel bottom bracket circuit, the torques are generated by the electric servomotor 183, amplified by the reduction gear 184, fed into a rotating system within the superposition gear 170, divided into several load paths within the stepper gear 160 and into the clutch means K1 to K6 fed in. This enables the coupling means to connect the individual idler gears to the shift shaft in the correct sequence. In other embodiments, not only an electrically operated actuator 172 can carry out the switching process at the actuation interface 181, but simple and cost-effective controls via a cable, hydraulics or other prior art controls are also possible. In order to sense absolutely or incrementally which gear is engaged during operation of the bottom bracket shifter, a sensor assembly 171 for gear step detection is preferably arranged within the actuation assembly 85 near the actuation interface 181. This assembly consists of a gear 187, which picks up the rotation angle information near the actuation interface 181 and forwards it to the sensor assembly 171. In an advantageous embodiment, a further gear ratio 186 is arranged behind the gear 187 in order to better prepare the angle information for the electronic position sensor. Figure 15a shows a perspective view of the idler gear 51 from Figure 4 in an advantageous embodiment. The idler gear 51 is on the switching shaft 67, not shown, and is designed with internal teeth 57. The external toothing 190 is in engagement with the drive gear 43, not shown. On the idler gear 51 shown, the teeth of the external teeth 190 are preferably connected to one another laterally via a web 191. In the illustration you can also clearly see that the coupling bodies 58, not shown here, can have a positive connection with internal teeth 57. In this idler gear 51, the internal toothing (57) is advantageously spaced laterally from the external toothing 190. In order to implement the 9 gears shown above within the bottom bracket gear, a number of teeth of 15 teeth on the idler gear 51 is necessary. This gearing has a very small root circle. In order to connect this idler gear 51 to the switching shaft 67 using the switching device 188, the internal toothing 57 must be on a larger diameter next to the external toothing 190. Such a preferred one-piece design can be produced using the extrusion process.

Figure 15b shows one of the idler gear 51 from Figure 4 viewed from the right. The teeth of the internal toothing 57 are connected to one another laterally via a web (191). Here the footbridge forms a flat surface on the ground. The web here is not a single web, but is formed circularly as an internal ring, the ring being made in one piece together with the external teeth 190 and the internal teeth 57.

Figure 15c shows a sectional view of the idler gear 51 from Figure 15b. On the idler gear 51, the teeth of the external toothing 190 and the teeth of the internal toothing 57 are completely connected to one another in a materially bonded manner via a reinforcing ring 78. The external toothing 190 and the internal toothing 57 are advantageously reinforced laterally by the ring 192. The material stresses in the tooth root under load are reduced in an advantageous manner.

Figure 15d shows the sectional view of the idler gear 51 from Figure 15b in a two-fold cutaway form. The component is cut at the bottom of the internal toothing 57 and at the lateral end of the external toothing 190 and the resulting parts are shown shifted laterally in order to make the principle clear. The reinforcing ring 78 is arranged axially between the external toothing 190 and the internal toothing 57 and is connected in a materially bonded manner. The idler gear 51 is made from a single piece of steel. It can be seen that a bearing 112 is arranged within the volume which is formed by the lateral surface of the external toothing 190. This bearing surface is preferably hardened and ground and is hardened and ground surface of the switching shaft 67 in contact. When the clutch means K1 is activated, there is no relative movement between the idler gear 51 and the switching shaft 67 and the radial forces can be transmitted directly from the external toothing 190 to the switching shaft 67. The flat surfaces 192 of the idler gears are also ground and ensure there is no axial play within the transmission. In a preferred embodiment, the transitions between the reinforcing ring 78, the external teeth 190 and the internal teeth 57 are rounded with radii in order to minimize the notch effect. Another description of the reinforcing ring is annular reinforcing disk.

If you compare FIG. 15 with FIG is characterized in that in the area in which it is connected to the idler gear 51, which has an internal toothing 57 which is laterally spaced, it is characterized in that the switching shaft 67 has two different outer diameters in this area.

Figure 16a shows a perspective view of the three output gears 37, 38, 39 from Figure 4. These three output gears 37, 38, 39 are made in one piece and, in a preferred embodiment, form wheel pairs 189 with the matching three idler gears 54, 55, 56 , which are arranged on the switching shaft. In a preferred embodiment, these three output gears 36, 37, 38 are also made in one piece together with the toothed output hollow shaft 36. The tooth root strength of the three output gears 37, 38, 39 is improved in an advantageous manner if the teeth of the external toothing 190 are at least partially connected to one another laterally via a web, as shown. The illustration also shows an exemplary embodiment of the bottom bracket circuit (10), characterized in that an annular reinforcing disk (78) is cohesively arranged axially laterally and between two output gears (38, 39), the outer diameter of the reinforcing disk (78) being larger than that Root circle diameter of at least one of the two gears.

Figure 16b shows an enlargement of a section from Figure 16a. The web 191 laterally bridges the tooth flanks of the output gear 38 and reinforces it. At the same time, this web 191, together with the side surfaces of the teeth of the driven gear 38, forms an annular reinforcing disk 78, which in turn also reinforces the teeth of the driven gear 39 and is materially connected to it. The side surfaces of the are also in the same preferred embodiment Output gear 37 is completely cohesively connected to the side surfaces of the gear 38 in order to increase the strength of the output gear 37. Generally speaking, the bottom bracket gear is preferably also characterized by the fact that at least two pairs of the drive or output gears 37, 38, 39, 41, 42, 43, which are arranged coaxially to the bottom bracket shaft 18, are cohesively connected to one another on the side surfaces of the teeth of the external teeth.

Figure 17a shows a perspective view of the three drive gears 43, 42, 41 from Figure 4. These three drive gears 43, 42, 41 are made in one piece and, in a preferred embodiment, form pairs of wheels 189 with the matching three idler gears 51, 52, 53, which are arranged on the switching shaft. In a preferred embodiment, these three drive gears 43, 42, 41 are also made in one piece together with the spline 73. The tooth root strength of the drive gear 41 improves in an advantageous manner if the teeth of the external toothing 190 of the drive gear 41 are materially connected to one another with the drive gear 42 on the side surface of the teeth of the external toothing. The illustration also shows that the side surface of the drive gear 42 preferably forms the web that laterally connects the teeth of the drive gear 41 to one another.

Figure 17b shows a further perspective view of the three drive gears 43, 42, 41 from Figure 4. The illustration shows a preferred embodiment, which is characterized in that a third drive gear 43 is arranged laterally next to the two drive gears 41, 42, which is fixed is connected to the two drive gears 41, 42 via an annular hollow body 193. The illustration also shows the screw connection 49 for the rotating circuit board, which is part of the sensor device. The bottom bracket circuit 10 is characterized in that a sensor board 44 with electronic components is attached to a drive gear 41, 42, the electronic components providing an electronic signal which represents at least the torque of the cyclist.

The exemplary descriptions within the illustrations in Figure 1 to Figure 17 make it clear that with the help of the novelty the described problems of integrating an advantageous bottom bracket circuit into an electric bicycle with auxiliary drive, in particular in the form of a mid-engine, are solved. The advantageous embodiment of the bottom bracket circuit shown above is characterized in that:

• the actuating device described and • the described high-strength gears and

• the switching device described and

• the sensor arrangement described and

• the described arrangement of the individual component volumes within the housing and

• the described connection of an electric auxiliary drive can be placed in the functional context in the manner described and this represents an improvement over the prior art.

Reference symbols

Frame

Top tube

down tube

Seat tube

battery

Pedals

Crank arm, crank front pulley

bracket

Bottom bracket gear, bottom bracket gear, gear unit

Control element

Traction device, straps

rear wheel

swingarm

Front suspension

Rear suspension

Swingarm bearing

bottom bracket shaft

Axis of rotation of the rear wheel

Belt tensioner

Fastening plates

Housing

Tension roller left protective cap left protective cap switching shaft

Mounting screw bearing axle

Needle bearings

Spacer sleeve shaft nut

abortionist

Shaft seal, 32', 32" ball bearing

Circlip

Gearbox housing on the right Gearbox housing on the left Output hollow shaft toothed 20 teeth output gear 32 teeth output gear 26 teeth output gear Spring

20 teeth drive gear 32 teeth drive gear 53 teeth drive gear PCB rotating PCB fixed to the housing Bottom bracket freewheel movable Bottom bracket freewheel rigid plain bearing

Screw connection, rotating plate. Screw connection, fixed to the housing. Idler gear with 15 teeth. Idler gear with 17 teeth. Idler gear with 20 teeth. Idler gear with 20 teeth. Idler gear with 21 teeth. Idler gear with 21 teeth

Internal gear coupling

Coupling body Strain gauge / sensor

Input hollow shaft pivoting support of the coupling means K1 pivoting support of the coupling means K2 pivoting support of the coupling means K3 pivoting support of the coupling means K4 pivoting support of the coupling means K5 pivoting support of the coupling means K6

shift shaft

Actuating gear selector shaft

Reference gear shift shaft

Stepper gearbox

Internal toothing of ring gear

Oil filling

Spline teeth first gear stage, first sub-gear second gear stage, second sub-gear lateral flat surface of the gear electronic components cohesively connected ring, reinforcing ring, reinforcing disk

Pinion, small gear spring-loaded pressure piece on the right side cover

Fastening screws electric drive assembly

Manual transmission assembly

Actuation assembly group, right outer cover

Gear with 15 teeth

Gear with 30 teeth Gear with 21 teeth

Gear with 14 teeth

Gear with 12 teeth

Gear with 55 teeth

Power electronics with direct phase connection

Chamber, room for electronics, dry

Detail with view at the first reduction level

Plug contacts

Freewheel

98' step gear, housing-fixed axle

Shaft electric motor side bar between teeth electric additional drive, electric motor

Attachment points electronic circuit board with sensor elements

, 105', 105" wave collar

Worm spring, tension spring, annular spiral spring

Depression in the lateral surface, pocket

Sliding disc

idler wheel

Pressure surfaces of the internal teeth

Sliding surfaces of the internal teeth

Bearing surfaces of the internal teeth, axial bores, swiveling support

Back of the coupling body

Pressure surface of the coupling body

Spring mounting surface, spring support surface Feather

opening

'120', 120" wave collar

Gearbox housing

output shaft

Sensor arrangement

Force from the idler gear to the clutch body (Fk)

Support force of the coupling body on the pivoting support (Fb)

Actuating torque Mb

Lever arm on the swiveling support

Lever arm Ik on clutch body 58

Lever arm Ib on clutch body 58

Lever arm Ish on the self-locking coupling body

Support force Fr on the self-locking coupling body

Lever arm Ir on the self-locking coupling body

Actuating torque of the camshaft Mn

Lever arm Ln on the camshaft

Lever arm lar on the self-locking coupling body

Actuating force Far

Bearing surface of the clutch body on the shift shaft

camshaft

Bearing surface of the pivoting support on the switching shaft

Support force of the clutch body on the shift shaft (Fa) self-locking clutch body

Grooves on lateral surface

Chambers for pivoting supports

Coupling body of the coupling means K1

Coupling body of the coupling agent K2

Coupling body of the coupling agent K3 Coupling body of the coupling agent K4

Coupling body of the coupling agent K5

Coupling body of the coupling agent K6

Recesses on the lateral surface of the pivoting supports

Lateral surface of the pivoting supports

Gear for actuating the clutch means K1

Gear for actuating the clutch means K2

Gear for actuating the clutch means K3

Gear for actuating the clutch means K4

Gear for actuating the clutch means K5

Gear for actuating the clutch means K6

Countersink, deepening of a short cylindrical ring on the reference gear

Stepper gear short cylindrical ring on the reference gear

Groove, slideway for ball

Internal teeth on the ring gear; Output of the stepper gearbox

Ring gear for actuating the clutch means K1, K2, K3

Ball of the stepper gear

Surface, link on the inner surface of the ring on the actuating gear

Groove or recess on the ring gear of the stepping gear inner raceway of the ball, inner diameter outer raceway of the ball, outer diameter

Superposition gear

Sensor assembly for gear level detection

Actuator, actuator assembly, servomotor assembly with gearbox, housing-fixed sun gear of the superposition gearbox, actuated sun gear on the superposition gearbox

Bridge of the superposition gear 176 planets of the superposition gear

177 reference wheel of the superposition gear

178 Actuating wheel of the superposition gear

179 planetary wheel axles

180 housing

181 actuation interface

182 182' Internal gearing on the superposition gear

183 electric servomotor

184 reduction gear on the servomotor

185 electronic position sensor

186 gear ratio on the position sensor

187 Gear on the position sensor

188 The entire switching device K

189 pairs of wheels

190 external teeth

191 bar, connecting bar between teeth

192 flat surfaces of the idler wheel

193 ring-shaped hollow body

X1 rotation axis bottom bracket shaft

X2 rotation axis switching shaft

X3 rotation axis electric motor

X4 rotation axis input shaft actuator; Rotary

X5 rotation axis reducer

X6 rotation axis reducer

X7 rotation axis reducer

X8 rotation axis coupling body

X9 rotation axis pivoting support

X10 rotation axis superposition gear

X11 rotation axis stepper gear K1 coupling agent 1

K2 coupling agent 2

K3 coupling agent 3

K4 coupling agent 4

K5 coupling agent 5

K6 coupling agent 6

E1 level 1

A1 section A1

Ma resulting torque on the coupling body

Mp self-locking torque on the coupling body

Mbt actuation torque at the actuation interface

K The coupling means, assembly of all coupling means

Claims

Claims Bottom bracket circuit (10) with an actuating device (85), in particular for a vehicle powered by muscle power, with a transmission, the transmission having a switching shaft (67) on which a plurality of idler gears (109) are mounted, which have a corresponding one A plurality of gears form pairs of gears (189), the idler gears (109) being connectable to the switching shaft (67) by means of coupling bodies (58), a superposition gear (170) with an actuation gear and a reference gear being arranged within the actuating device (85), and wherein the actuating gear of the superposition gear (178) and the reference gear of the superposition gear (177) are arranged coaxially with one another and are not coaxial with the switching shaft (67). Bottom bracket circuit (10) according to claim 1, characterized in that the switching shaft (67) is firmly connected to a reference gear (69). Bottom bracket circuit (10) according to claim 2, characterized in that the reference gear (69) is located laterally next to and coaxial with that of the switching shaft (67). Bottom bracket gear (10) according to claim 2 or 3, characterized in that the external toothing of the reference gear (69) is in engagement with the reference gear of the superposition gear (177). Bottom bracket gear (10) according to one of claims 2 to 4, characterized in that There is an actuating gear (68) coaxially with the reference gear (69) and to the side next to the reference gear (69). Bottom bracket circuit (10) according to claim 5, characterized in that the actuating gear (68) is designed with external teeth and internal teeth (71). Bottom bracket circuit (10) according to claim 5 or 6, characterized in that the internal teeth of the actuating gear (68) are directly or indirectly connected to the switching means or the coupling means. T pedal bearing shift (10) according to one of claims 4 to 6, characterized in that the external teeth of the actuating gear (68) are in engagement with an actuating gear of the superposition gear (178). Bottom bracket circuit (10) according to one of claims 1 to 8, characterized in that a superposition gear (170) is arranged within the actuating device (85), the actuation gear of the superposition gear (178) and the reference gear of the superposition gear (177) having external teeth and an internal toothing (182, 182 '). Bottom bracket circuit (10) according to at least one of claims 1 to 9, characterized in that an actuating sun gear (174) is arranged concentrically to the reference gear of the superposition gear (177). Bottom bracket circuit (10) according to at least one of claims 1 to 10, characterized in that a sun gear (173) fixed to the housing is arranged concentrically to the actuating gear of the superposition gear (178) and this sun gear (173) fixed to the housing is at least rotated indirectly or directly with a frame or Housing is connected. Bottom bracket circuit (10) according to at least one of claims 1 to 11, characterized in that the actuating sun gear (174) can be rotated through an angle relative to a frame or housing in order to actuate the bottom bracket circuit. Bottom bracket circuit (10) according to at least one of claims 1 to 12, characterized in that the actuating gear of the superposition gear (178) and the reference gear of the superposition gear (177) and the actuating sun gear (174) and the sun gear fixed to the housing (173) are arranged as a planetary gear, whereby the planetary gear is not coaxial with the switching shaft (67). Bottom bracket circuit (10) according to at least one of claims 1 to 13, characterized in that within the planetary gear there are planetary gears (176) which are connected to one another via planetary gear axles (179) and at least one planetary gear (176) is in engagement with the actuating sun gear ( 174) and wherein at least one further planetary gear (176') is in engagement with the sun gear (173) fixed to the housing and wherein within the planetary gear there are planetary gears (176) which are connected to one another via planetary gear axles (179) and wherein at least one Planet gear (176) is in engagement with the reference gear of the superposition gear (177) and at least one further planet gear (176 ') is in engagement with the actuating gear of the superposition gear (178) and the planet gear axes (179) on the web of the superposition gear (175) are arranged. Bottom bracket circuit (10) according to at least one of claims 1 to 14, characterized in that the reference gear of the superposition gear (177) and the reference gear (69) are coplanar to one another and that their axes of rotation are parallel to one another. Bottom bracket circuit (10) according to at least one of claims 1 to 15, characterized in that the actuating gear of the superposition gear (178) and the actuating gear (68) are coplanar to one another and that their axes of rotation are parallel to one another. Bottom bracket circuit (10) according to at least one of claims 1 to 16, characterized in that the actuation gear (68) is rotatably mounted on the reference gear (69) for actuation. Bottom bracket circuit (10) according to at least one of claims 1 to 17, in particular for a muscle-powered vehicle with an electric auxiliary drive, characterized in that a first sub-gear (74) and a second sub-gear (75) are connected in series for power transmission, whereby the the first sub-gear (74) and the second sub-gear (75) have a switching shaft (67) on which a plurality of idler gears (51, 52, 53, 54) are mounted, which are connected to a corresponding plurality of gears (37, 38, 41 , 42) form pairs of wheels of the respective partial transmission, the idler wheels (51, 52, 53, 54) being connectable to the switching shaft (67) by means of coupling bodies. Bottom bracket circuit (10) according to at least one of claims 1 to 18, characterized in that the outside diameter of the reference gear (69) and the outside diameter of the actuation gear (68) are larger than the outside diameter of the switching shaft (67). Bottom bracket circuit (10) according to at least one of claims 1 to 19, characterized in that the actuating gear (68) has an internal toothing (71) in addition to the external toothing, the internal toothing (71) having at least two Pinions (79) are connected, these pinions (79) being at least indirectly connected to the pivotable supports (64, 65). Bottom bracket circuit (10) according to at least one of claims 1 to 20, characterized in that the axis of rotation (X2) of the switching shaft (67) is arranged coaxially to the axis of rotation (X11) of a stepping gear (160) and the stepping gear (160) is at least large Parts are located on the side next to the switching shaft (67). Bottom bracket circuit (10) according to at least one of claims 1 to 21, characterized in that a switching process is initiated at least when the actuating gear (68) is rotated relative to the reference gear (69) and this rotation is triggered via a superposition gear (170), which is spaced parallel to the axes of rotation and not coaxial with the switching shaft (67). Bottom bracket circuit (10) according to at least one of claims 1 to 22, characterized in that a signal which the cyclist triggers on an operating element (11) indirectly triggers or causes an angular rotation on the actuating sun gear (174) of the actuating device (85). Bottom bracket circuit (10) according to at least one of claims 1 to 23, characterized in that a signal which the cyclist triggers on a control element (11) indirectly triggers or causes an activation of the servomotor assembly with gear (172). Bottom bracket circuit (10) according to at least one of claims 1 to 24, characterized in that a servomotor assembly with a gear (172) is arranged within the actuating device (85) and is in a torque-transmitting connection with the actuating sun gear (174). Bottom bracket circuit (10) according to at least one of claims 1 to 25, characterized in that a sensor for gear step detection (171) is arranged within the actuating device (85). Bottom bracket circuit (10) according to at least one of claims 1 to 26, characterized in that a sensor for gear stage detection (171) is connected directly or indirectly to the actuating sun gear (174) or to the servomotor assembly with gearbox (172). Bottom bracket circuit (10) according to at least one of claims 1 to 27, characterized in that there are at least two pivotable supports (64, 65) within the switching shaft (67), which are equipped at their ends with a toothed pinion (79) and are located indirectly or are directly in engagement with the internal teeth (71) of the actuating gear (68). Bottom bracket circuit (10) according to at least one of claims 1 to 28, characterized in that the reference gear (69) is firmly connected to a cylindrical ring (159) on a side surface, the ring (159) being arranged concentrically to the reference gear (69). and has a surface (166) which can come into contact with a ball (165), and wherein the surface (166) has depressions which form a backdrop-like surface. Bottom bracket circuit (10) according to at least one of claims 1 to 29, characterized in that the actuation gear (68) is firmly connected to a cylindrical ring (161) on a side surface, the ring (161) being arranged concentrically to the actuation gear (68). and wherein the ring (161) has a groove or opening in which the ball (165) is movably disposed and wherein the ring is disposed proximate and rotatable relative to the cylindrical ring on the reference gear (159). Bottom bracket circuit (10) according to at least one of claims 1 to 30, characterized in that a ring gear (164) has internal teeth (163), the internal teeth (163) being in mesh with at least two toothed pinions (79), the two toothed pinions (79) are connected to pivotable supports (61, 62) and wherein the ring gear (164) is concentric to the actuating gear (68) and wherein the ring gear (164) has a surface (166) which is in contact with a ball ( 165) can occur and wherein the surface (166) has depressions or depressions into which the ball (165) can snap.. Bottom bracket circuit (10) according to at least one of claims 1 to 31, characterized in that at least partially during the switching operations within the actuating device (85), the ring gear (164) can assume a first state in which it moves in the same direction together with the actuating gear (68) relative to the switching shaft (67) and can assume a second state in which it moves relative to the switching shaft (67 ) does not carry out any rotational movement.