CLUTCH DEVICE

Description

[0001] The invention relates to a clutch device for a bicycle and a gear shift for a bicycle with such a clutch device.

[0002] The bicycle can also be an electric bicycle. Electric bicycles have an auxiliary motor that assists the cyclist's pedaling. Gears on a bicycle, including an electric bicycle, ensure that pedaling can be maintained at a relatively constant cadence across a wide speed range.

[0003] The following gear systems are currently used on bicycles and electric bicycles, according to the state of the art: 1) Hub gears 2) Derailleur gears 3) Bottom bracket gears

[0004] When tackling diverse tasks in various environments where bicycles are used, a switchable gearbox is indispensable in most cases. While a single-speed bicycle, i.e., a bicycle with a fixed gear ratio, may suffice in flat urban traffic, its use reaches its limits over longer distances, such as those prevalent in rural areas.

[0005] Steep climbs or descents in mountain biking, heavy loads in passenger or freight transport, ergonomic considerations on long-distance journeys, or ever-increasing maximum speeds all require a gear ratio that the rider can adjust while riding, changing the applied torque and rotational speed. This allows the rider to adapt their cadence and pedal force to the specific situation.

[0006] In a bicycle, the aforementioned transmissions are usually implemented in three different ways: as a switchable traction transmission, planetary gear transmission or spur gear transmission.

[0007] Planetary gear drives are mostly used inside the hub housing on the rear wheel, whereas spur gear drives are often located near the bottom bracket axle.

[0008] Traction gears primarily connect the bottom bracket axle to the rear wheel hub, especially in the form of a derailleur system, as described below.

[0009] Over the past sixty years, chain drive systems with a derailleur at the rear axle have become widespread on bicycles. A rotating bottom bracket with one or more chainrings is mounted to the frame, which forms the load-bearing part of the bicycle and includes all its mounting points for the front fork, seat post, and rear wheel. A cassette consisting of up to thirteen different-sized sprockets is located on the rear wheel hub. A derailleur is attached to a dropout, which connects the frame to the rear axle. Its function is to guide the chain onto the sprockets of the cassette and enable gear changes. Additionally, a front derailleur, usually mounted on the seat tube at the bottom bracket, allows the rider to shift between different chainrings. Bicycles with a drivetrain system like the one described above are generally referred to as derailleur-geared bicycles.

[0010] Because the components of a bicycle with a derailleur gear system are mounted externally on the frame, they are particularly exposed to environmental influences, resulting in increased wear and tear and a significant decrease in efficiency after a short period of use. The resulting short maintenance intervals, especially on bicycles with auxiliary drive, become very costly due to the necessary replacement of the torque-transmitting components of the drivetrain. Furthermore, the derailleur, in its exposed position on the rear wheel, is at increased risk of damage from falls or similar incidents.

[0011] In so-called hub gears, as well as gears located near the bottom bracket (hereinafter referred to as bottom bracket gears), the components are protected from external influences within a housing. A hub gear typically features one or more planetary gear sets connected in series, which share the rear wheel's axis of rotation as the coaxial axis of rotation for the individual gear stages. Hub gears are also often called geared hubs.

[0012] Hub gears are essentially switchable planetary gear systems integrated into the hub housing of the rear wheel. These gears are encapsulated from the external environment within a housing and are therefore largely maintenance-free. However, a disadvantage of hub gears is their significant weight at the rear wheel, which results in an unfavorable weight distribution. This weight is bothersome not only when carrying the bicycle, but also when cornering or riding off-road at a sporty pace.

[0013] Another disadvantage of the hub gears currently available on the market is the inability to shift under load. A cyclist who is pedaling uphill under load, for example in sixth gear with high torque, and wants to shift down a gear, must first take the load off the pedals with conventional hub gears to enable the shift into fifth gear.

[0014] The rider's torque is typically transmitted via a drive shaft to the input shaft of the hub gear, where it is converted by the planetary gears and transferred to the hub shell, which consequently serves as the output shaft of the transmission. The input shaft is also often called the drive shaft. The spokes attached to the hub shell connect the transmission to the rim, which, via the tire, transmits the torque to the road surface. The design using a toothed belt as the drive shaft is significantly lower maintenance-intensive and better protected against external influences compared to a chain.

[0015] Derailleur gears offer improved shifting performance under load compared to hub gears. As mentioned earlier, derailleur gears on the rear wheel have many sprockets arranged side-by-side in a stepped configuration. The front derailleur guides the chain onto a specific sprocket depending on the selected gear, thus achieving a specific gear ratio. This gear shifting is possible even under load with a derailleur gear system.

[0016] Derailleur gears were historically designed to transmit solely the mechanical pedaling power generated by a human to the rear wheel. If the bicycle also has an auxiliary motor, this – in the case of the e-bikes discussed here – is typically located at the bottom bracket. With these so-called mid-drive motors, the power of the cyclist at the crank and the power of the electric motor are combined and transmitted to the gears, resulting in a very high power output. In this configuration, derailleur gears or hub gears are commonly used today because there is insufficient space for a gear system at the bottom bracket.

[0017] As already mentioned, derailleur gears have a disadvantage in that their components—namely the sprockets on the rear hub, at least one chainring, and the chain along with the derailleur—are unprotected and therefore easily become dirty. Wear is significantly increased due to the high power that needs to be transmitted when an auxiliary motor is present. A derailleur gear system is therefore comparatively maintenance-intensive. The maintenance interval for an e-bike with a derailleur gear system can range from 600 to 1200 km. This is a disadvantage. Hub gears on the rear wheel are also used on e-bikes, either instead of or in combination with derailleur gear systems.

[0018] A more advantageous weight distribution results when the gear system is positioned centrally on the bicycle, as is the case with bottom bracket gear systems. However, current bottom bracket gear systems are quite large, leaving no space around the bottom bracket for an electric motor. Furthermore, bottom bracket gear systems are already so heavy that the additional weight of an auxiliary drive would result in an e-bike that is too heavy for everyday use or for riding with a depleted battery. Additionally, the shifting performance under load is similarly poor with bottom bracket gear systems as with internal gear hubs.

[0019] Bottom bracket gearboxes are usually spur gear gearboxes, as described, for example, in DE 10 2009 060 484 B4, whose housing is attached to the main frame of the bicycle. This utilizes a protected and compact installation space around the bottom bracket axle to achieve the gearbox's function. The input shaft of a bottom bracket gearbox is usually directly connected to the cranks and pedals of the bicycle. A drive shaft on the output shaft transmits the torque to the rear wheel. This type of bicycle gearbox has the advantage that the weight of the gearbox is located at a central and low point, which has a positive effect on the center of gravity and thus on the handling characteristics. However, for the reasons mentioned above, sporty use of a bicycle with a bottom bracket gearbox or hub gear is difficult.

[0020] In gear drives, the various gear ratios, hereinafter referred to as gears or gear stages, are achieved through combinations of several gear pairs or their individual ratios. Since in spur and planetary gear drives, all gears of each input or intermediate shaft are usually engaged with the corresponding gear of the following intermediate or output shaft at all times, one gear of each pair must be able to rotate freely on its shaft without transmitting torque. By means of switchable clutches, individual gears of this free rotation can be connected to the corresponding shaft or to a component downstream in the torque flow, thus transmitting torque. The activation of individual clutches directs the torque through the gear pairs, which together produce the desired overall gear ratio of a gear.

[0021] The couplings can be designed as radial or axial couplings, mostly as positive-locking couplings, which predominantly transmit torque in only one direction of rotation, based on the principle of a freewheel. Figures 9 and 10 of WO 98 / 52817 A1 clearly illustrate the function of such a radial coupling.

[0022] Switchable axial couplings are usually designed as jaw couplings and each has one axially displaceable and one axially fixed component, as also described in WO 98 / 52817 A1. Fig. 6 and 7 shown.

[0023] The face teeth of an axial coupling offer the advantage of a significantly larger force-transmitting area within the same installation space compared to a radial coupling with pawls. This advantageously reduces the surface pressure.

[0024] The axial clutches are controlled, as illustrated, for example, in WO 98 / 52817 A1, by a so-called actuating element, hereinafter also referred to as the shift drum. This is a cylindrical body in which helical grooves and / or protrusions and depressions are embossed. See also Fig. 15 of WO 98 / 52817 A1. Within hub gears, the shift drum is usually rotatably mounted in a fixed hollow axle, hereinafter referred to as the main axle, with the angular position of the shift drum relative to the main axle defining the states (active, inactive) of the individual clutches for the gears. This angular position of the hollow axle can be controlled by the rider from the bicycle handlebars, either mechanically via Bowden cables or electrically via an actuator.

[0025] Considering a single axial clutch according to WO 98 / 52817 A1, the two halves of the face gear are usually held together by a spring when engaged. To disengage the axial clutch, the spring-loaded clutch half is typically moved axially by a sliding ring connected to the shift drum, thus opening the clutch. When shifting under load, certain functional surfaces of the movable clutch half are in frictional contact with adjacent surfaces of the fixed clutch half. To shift from one gear to another under load, static friction must first be overcome. Subsequently, the movable clutch component must be moved further under the influence of sliding friction. Due to high frictional forces, shifting under load is difficult or even impossible.

[0026] US Patent 2023 / 0234535 A1 discloses a method for immobilizing a vehicle, wherein the vehicle's drivetrain includes a clutch, in particular a freewheel. Upon user input to activate the immobilizer, an actuator is controlled to activate the immobilizer. In one embodiment, the actuator is configured to position a cylindrical pin in a groove located on the circumference of the clutch and between a first and a second clutch component. The pin is guided through the groove when the clutch rotates, and the groove has a constriction such that, when the clutch rotates, the first and / or the second clutch component is displaced axially by means of the pin and the constriction.

[0027] DE 199 03 441 A1 discloses a switchable clutch for a drive unit for vehicles, in particular for bicycles with an electric motor, with a switchable jaw clutch between the gearbox and the drive gear for bridging a freewheel in the direction of rotation opposite to the drive direction. The jaw clutch is engaged and disengaged by a lever that can be operated manually. A sliding element with a lever housing acts on the jaws, with the lever assigning a defined position to the lever housing. This ensures precise control of two end positions for the jaw clutch to bridge the freewheel.

[0028] The subsequently published document DE 10 2023 211 468 B3 of the same applicant discloses a coupling device in the form of a jaw coupling, in which the side surfaces of the end teeth (the jaws) of the two coupling halves do not lie in a radial plane passing through the axis of rotation of the respective coupling half, but are inclined relative to this radial plane. This can cause the end teeth to "slide" against each other when the driving coupling half is subjected to an operating torque, and the coupling device to open unless it is forcibly held in the closed position, i.e., locked. In other words, the jaw coupling can function as a slip clutch in this state.In this way, the opening of the clutch mechanism can be assisted by the operating torque, which is applied, for example, by the rider of the bicycle whose gearbox contains the clutch mechanism. This also makes shifting under load easier, since the operating torque itself can be used to initiate the opening process of the clutch mechanism and thus the shifting process.

[0029] Since the reverse process, i.e., closing the coupling device, also requires working against the assisted opening of the coupling device with the help of the actuating device, greater forces and / or additional machine elements such as springs are necessary.

[0030] The object of the present invention is to provide a coupling device with improved switching capability under load.

[0031] This problem is solved by a clutch device according to claim 1 or by a gear shift for a bicycle according to claim 20 with such a clutch device. Advantageous embodiments of the invention are contained in the dependent claims.

[0032] The coupling device under consideration is designed for the selective transmission of torque from a first shaft or hub to a second shaft or hub, particularly for a bicycle gearbox. It comprises a first coupling half, which is rotationally fixed to the first shaft or hub, and a second coupling half, which is rotationally fixed to the second shaft or hub.Furthermore, it has a first opening device, which is configured to generate a first opening force from an operating torque applied to the first clutch half, in particular by the operation of a bicycle with a gearshift mechanism containing the clutch device. This first opening force allows the clutch device to be moved from a closed state, in which a torque can be transmitted from the first clutch half to the second clutch half, to an open state, in which no torque can be transmitted from the first clutch half to the second clutch half. It also has an actuating device configured to control the first opening device.

[0033] According to the invention, the first opening device is spatially separated from the torque transmission area of ​​the coupling device, i.e., the spatial area in which, in the closed state of the coupling device, a torque transmission from the first coupling half to the second coupling half can take place.

[0034] In this way, more degrees of freedom are available in the design of the coupling device than if the torque transmission area had to fulfill the function of supporting the opening of the coupling device in addition to its actual function of torque transmission. In particular, it becomes possible to design and optimize the two spatial areas—the torque transmission area and the first opening mechanism—separately, without having to consider interactions between the two functions. This can also simplify the design of the actuating device, which no longer needs to act directly on the torque transmission area.

[0035] Simultaneously, the problem of improving the clutch's shifting capability under load is solved by using operating torque to assist the clutch's opening. This improves shifting capability under load because the operating torque itself can be used to initiate the clutch's opening process and thus the shifting process.

[0036] In a preferred embodiment of the invention, the first opening device is arranged radially further outwards than the torque transmission area.

[0037] This spatial arrangement can result in a compact design of the coupling device with a short axial length. Furthermore, the radially more outward-positioned first opening mechanism for connection to the actuating device can be more easily accessible from a design perspective.

[0038] In a further preferred embodiment of the invention, a movable coupling half, which is one of the first coupling half and the second coupling half, is movable in the axial direction of the first shaft or hub or the second shaft or hub, and the first opening device has: at least one first cam surface arranged on the movable coupling half, which extends in a first direction substantially circumferentially to the movable coupling half and which has such a first curvature that the position of a point on the first cam surface changes in the axial direction along the first direction of extension, and at least one first cam follower which is configured to contact the first cam surface along the first direction of extension when the movable coupling half rotates, thereby generating the first opening force and causing movement of the movable coupling half in the axial direction, thereby moving the coupling device from the closed state to the open state.

[0039] The actuating device is designed to engage at least one first cam follower with the first cam surface and to disengage it from the first cam surface.

[0040] This allows the first opening force to be generated from the operating torque in a simple manner, by the at least one first cam follower, during its movement along the first direction of extension, causing a change in the axial position of its point of contact with the at least one first cam surface, and thus a movement of the entire at least one first cam surface and, since the at least one first cam surface is arranged on the movable coupling half, also of the entire movable coupling half. The at least one first cam surface is preferably oriented such that the movement of the movable coupling half occurs precisely in the opening direction of the coupling device, i.e., in the axial direction in which the coupling device can be moved from the closed state to the open state.Furthermore, the at least one first cam follower is preferably arranged such that its position in the axial direction does not change during its movement along the first extension direction.

[0041] In a preferred embodiment of this invention, at least one first cam surface and at least one first cam follower together form a wedge drive. In this way, they together generate the first opening force and thus the movement of the movable coupling half in the axial direction.

[0042] The term "wedge drive" is used here in its usual mechanical sense as a drive consisting of a first body with a first surface and a second body with a second surface, wherein the first and second surfaces are in contact with each other and movable relative to each other, wherein the first and / or second surface is inclined or curved with respect to a first direction, and wherein the first body is movable in the first direction and the second body is at least prevented from moving in the first direction, such that a movement of the first body in the first direction results in a movement of the first and / or second body with a component orthogonal to the first direction. The angle of inclination or curvature of the first or second surface with respect to the first direction simultaneously results in a force transmission between the force introduced into the first body and the force acting on the first or second surface.the force component acting orthogonally to the first direction on the second body.

[0043] In this case, at least the first cam surface is curved due to the first curvature relative to the first direction of extension. If the cam follower is stationary in the position where it contacts the first cam surface, a rotation of the movable coupling half will thus generate a force acting on the movable coupling half with a component orthogonal to the first direction of extension and therefore in the axial direction, i.e., the first opening force, and the movable coupling half will move in the axial direction.

[0044] In a preferred embodiment of this invention, the first opening device further comprises a first holding-open surface which is arranged on the movable coupling half such that the coupling device is in the open state when the first holding-open surface is contacted by the at least one first cam follower, wherein the first holding-open surface is arranged adjacent to a region of the at least one first cam surface, when the coupling device is in the open state when contacted by the at least one first cam follower.

[0045] In this way, following the movement of the movable coupling half in the opening direction of the coupling device and the resulting opening of the coupling device, it is possible to ensure that the coupling device remains in the open state. The first holding-open surface preferably has the form of an annular, flat surface, which is arranged orthogonally to the axis of rotation of the movable coupling half and concentrically to it. Thus, the at least one first cam follower can contact the first holding-open surface for any length of time, in particular over several revolutions of the movable coupling half, without the axial position of the movable coupling half changing. The coupling device can therefore be held open continuously as soon as the at least one first cam follower makes contact with the first holding-open surface.Here too, at least one first cam follower is preferably arranged such that its position in the axial direction does not change when the first open surface is contacted.

[0046] In a preferred embodiment of the invention with at least one first cam surface and at least one first cam follower, the at least one first cam follower can be engaged with and / or disengaged from the at least one first cam surface by a movement of the at least one first cam follower in the radial direction of the movable coupling half, in particular by a lever or slider mechanism.

[0047] This simply achieves the function of the actuating device to engage and disengage the at least one first cam follower from the at least one first cam surface. A movement of the at least one first cam follower in the radial direction of the movable coupling half is particularly suitable for this purpose if the first opening device is arranged radially further out than the torque transmission area, because in this case the at least one first cam surface is also particularly easily accessible from the radial outside. A lever or slide mechanism by which the at least one first cam follower is pivoted or inserted into the at least one first cam surface from the radial outside is also a component that is easy to construct and can be easily controlled by a mechanical actuating device.

[0048] In a preferred embodiment of this invention, the movement of the at least one first cam follower in the radial direction of the movable coupling half when engaging with the at least one first cam surface is at least partially effected by a spring, in particular by the relaxation of the spring.

[0049] The spring thus causes the clutch assembly to open, even when the actuating device is not engaged. This design therefore provides a simple way to implement a clutch assembly that is open when at rest. This is particularly advantageous if the actuating device fails, for example due to an interruption in an electrical connection or other defect in an electrical actuating device, as the clutch assembly—and potentially all clutch assemblies in the transmission—will then open, thus preventing the transmission from locking up.

[0050] In a further preferred embodiment of the invention with at least one first cam surface and at least one first cam follower, the first opening device has a plurality of first cam surfaces which are arranged along the circumferential direction of the movable coupling half.

[0051] In this way, the individual first cam surfaces, distributed around the circumference of the movable coupling half, can each be shorter than if there were only a single first cam surface. This also allows the generation of the first opening force, and thus the opening of the coupling device, to occur more quickly as soon as the at least one first cam follower is engaged with one of the first cam surfaces by the actuating device.

[0052] In a further preferred embodiment of the invention with at least one first cam surface and at least one first cam follower, the first opening device has a plurality of first cam followers which are arranged along the circumferential direction of the movable coupling half.

[0053] In this way, a more uniform generation of the initial opening force can be achieved, distributed across several points around the circumference of the movable coupling half. Distributing the initial opening force across these multiple first cam followers also reduces the load on each individual first cam follower. In particular, the frictional force acting between each first cam follower and the first cam surface it contacts is correspondingly reduced. Preferably, the multiple first cam followers are arranged at substantially equal intervals along the circumference of the movable coupling half.

[0054] According to the invention, the coupling device has a second opening device which is configured to generate a second opening force without using the operating torque, by which the coupling device can be moved from the closed state to the open state, wherein the actuating device is configured to control the second opening device.

[0055] The second opening device thus provides an additional means of moving the coupling device from the closed to the open state by means of the second opening force. Preferably, the first and second opening devices are effective under different operating conditions of the coupling device, in particular at different operating torques. The operating torque at which the second opening device is effective is preferably lower than the operating torque at which the first opening device is effective.

[0056] When a second opening force is mentioned here, this force is preferably independent of the first opening force. It does not necessarily arise in addition to the first opening force.

[0057] In this embodiment of the invention, the coupling device, with the aid of the second opening device, is able to generate the second opening force even when stationary or at low rotational speed, by which the coupling device can be moved from the closed state to the open state.

[0058] When the clutch device according to the invention is used in a bicycle gearbox, the first opening device preferably becomes effective when the rider pedals while riding, thereby applying a potentially quite large operating torque to the clutch device, and simultaneously wants to engage a different gear, i.e., when he or she wants to shift under load. In this case, the operating torque is used to generate a first opening force for the clutch device.

[0059] In contrast, the second opening mechanism in a bicycle gearbox is preferably activated when the rider is not pedaling, or only pedaling lightly or slowly, and wishes to shift gears while stationary, i.e., when shifting is to be done without or under light load. In this case, little or no operating torque is available at the clutch mechanism. Conversely, no high frictional force needs to be overcome when opening the clutch; that is, only a small opening force is required. Thus, a second opening force can be generated by the second opening mechanism, and therefore without using the operating torque, to open the clutch mechanism.

[0060] In this embodiment of the invention, the actuating device is configured to control both the first opening device and the second opening device.

[0061] In a preferred embodiment of this invention, the second opening device is arranged radially further outwards than the torque transmission area.

[0062] This can result in the same advantages as with the corresponding arrangement of the first opening device.

[0063] In another preferred embodiment of this invention, the second opening device comprises: at least one second cam surface arranged on the movable coupling half, which extends in a second direction substantially radially to the movable coupling half and which has such a second curvature that the position of a point on the at least one second cam surface changes in the axial direction along the second direction of extension, and at least one second cam follower configured to contact the at least one second cam surface along the second direction of extension, thereby generating the second opening force and causing movement of the movable coupling half in the axial direction, thereby moving the coupling device from the closed state to the open state. wherein the actuating device is configured to engage the at least one second cam follower with the at least one second cam surface, to move it along the second extension direction and to disengage it from the second cam surface.

[0064] This allows the second opening force to be generated easily without using the operating torque, by the at least one second cam follower, during its movement along the second direction of extension, causing a change in the axial position of its point of contact with the at least one second cam surface, and thus a movement of the entire second cam surface and, since the second cam surface is arranged on the movable coupling half, also of the entire movable coupling half. The at least one second cam surface is preferably oriented such that the movement of the movable coupling half occurs precisely in the opening direction of the coupling device, i.e., in the axial direction in which the coupling device can be moved from the closed state to the open state.Furthermore, the at least one second cam follower is preferably arranged such that its position in the axial direction does not change during its movement along the second extension direction.

[0065] In a preferred embodiment of this invention, at least one second cam surface and at least one second cam follower together form a wedge drive. In this way, they together generate the second opening force and thus the movement of the movable coupling half in the axial direction.

[0066] In this case, at least the second cam surface is curved relative to the second direction of extension due to the second curvature. When the cam follower moves in the second direction of extension upon contacting the second cam surface, a force is generated acting on the movable coupling half with a component orthogonal to the second direction of extension, and thus in the axial direction – i.e., the second opening force – and the movable coupling half moves in the axial direction.

[0067] In contrast to the first direction of extension of the at least one first cam surface, the second direction of extension of the at least one second cam surface does not run circumferentially, but radially to the movable coupling half. A movement of the at least one second cam follower along the second direction of extension when it contacts the at least one second cam surface is therefore independent of a rotation of the movable coupling half. In particular, such a movement of the at least one second cam follower can also occur when the movable coupling half is stationary, for example, when the bicycle whose gearshift mechanism contains the coupling device is stationary.Since the relative movement between the at least one second cam surface and the at least one second cam follower - unlike in the first opening device - cannot be generated from the rotation of the movable coupling half, the actuating device is additionally designed to move the at least one second cam follower along the second extension direction.

[0068] The two different directions of extension also allow at least one first and at least one second backdrop surface to be arranged close together and even overlapping, thus making good use of the available construction space.

[0069] In a further preferred embodiment of the invention with a second opening device, the at least one second cam surface has a second holding-open surface, wherein the coupling device is in the open state when the second holding-open surface is contacted by the at least one second cam follower.

[0070] This can result in the same advantages as for the first open space.

[0071] In a further preferred embodiment of the invention with at least one second cam surface and at least one second cam follower, the at least one second cam follower can be engaged with and / or disengaged from the second cam surface by moving the at least one second cam follower in the radial direction of the movable coupling half, in particular by a lever or slider mechanism.

[0072] This can result in the same advantages as with the corresponding operation of at least one first backstage follower.

[0073] In a preferred embodiment of this invention, the movement of the at least one second cam follower in the radial direction of the movable coupling half when engaging with the at least one second cam surface and / or the movement of the at least one second cam follower along the second extension direction is at least partially effected by a spring, in particular by the relaxation of the spring.

[0074] This can result in the same advantages as with the corresponding operation of at least one first backstage follower.

[0075] In a further preferred embodiment of the invention with at least one second cam surface and at least one second cam follower, the second opening device has a plurality of second cam surfaces which are arranged along the circumferential direction of the movable coupling half.

[0076] This can result in the same advantages as having a corresponding majority of initial backdrop areas.

[0077] In a further preferred embodiment of the invention with at least one second cam surface and at least one second cam follower, the second opening device has a plurality of second cam followers which are arranged along the circumferential direction of the movable coupling half.

[0078] This can result in the same advantages as having a corresponding majority of first-line followers.

[0079] In a preferred embodiment of the invention with at least one first and at least one second cam surface as well as with at least one first and at least one second cam follower, the at least one first cam surface is at least partially identical with the at least one second cam surface, and / or the at least one first cam follower is substantially identical with the at least one second cam follower.

[0080] If the at least one first cam follower is substantially identical to the at least one second cam follower, it is preferred that this cam follower has a first and a second surface, wherein the first surface with a first cam surface and the second surface with a second cam surface each form a wedge drive. Preferably, the first surface points in the first direction of extension and / or the second surface in the second direction of extension. Alternatively, instead of a first and a second surface, it can also be a first and a second surface segment of a common, continuous surface of the cam follower.

[0081] As mentioned above, the two different directions of extension of the at least one first and at least one second cam surface allow the two cam surfaces to be arranged close together and even overlapping. According to the present embodiment, the two cam surfaces can even be at least partially identical, i.e., at least one partial surface of the at least one first cam surface is also a partial surface of the at least one second cam surface. Preferably, starting from this common partial surface, the at least one first cam surface then extends substantially circumferentially, and the at least one second cam surface extends substantially radially, to the movable coupling half.

[0082] In this way, depending on the operating torque applied to the coupling device, either the first or the second opening mechanism is automatically activated: With low or no operating torque, the at least one second cam follower is moved by the actuating device along the second direction of extension, thereby generating the second opening force. With a higher operating torque, a correspondingly larger second opening force would be required, but the actuating force of the actuating device might not be sufficient to generate it. Instead, the at least one first cam follower (which, according to this variant, can be identical to the at least one second cam follower) moves along the first direction of extension due to a rotation of the movable coupling half, thereby generating the correspondingly larger first opening force from the operating torque.

[0083] The partially identical design of the at least one first and at least one second cam follower surface, or the identity of the at least one first and at least one second cam follower, can result in better use of installation space, a more compact construction and / or a reduction in the number of parts of the coupling device.

[0084] In a further preferred embodiment of the invention described above, which further comprises a first open-open surface and a second open-open surface, the first open-open surface is essentially identical to the second open-open surface.

[0085] The identical first and second holding surfaces can result in, in particular, better utilization of installation space and a more compact design of the coupling device. This is especially true if the first and second holding surfaces have the shape of an annular area extending over the entire circumference of the movable coupling half, since the holding surface then occupies a relatively large installation space, which, however, only needs to be provided once.

[0086] The invention further relates to a gear shift for a bicycle with at least one clutch device according to the invention.

[0087] As explained above, the use of the clutch device according to the invention in a bicycle gearbox makes it possible to shift gears even under load. This increases riding comfort for the cyclist, as they no longer need to briefly interrupt their pedaling or at least relieve pressure on the pedals to perform the shift. Especially when climbing hills, particularly when standing on the pedals, such an interruption or relief of pressure on the pedals is difficult or at least disrupts the pedaling rhythm, thus throwing the rider off their stride and potentially costing valuable time, especially in competitive cycling. An automatic shifting system can also be implemented.

[0088] The following drawings will be used to explain exemplary embodiments of the invention in more detail. They show: Fig. 1a shows a cross-section of a coupling device according to the invention along the axis of rotation of the coupling device in the closed state; Fig. 1a shows a cross-section of a coupling device according to the invention along the axis of rotation of the coupling device in the open state; Fig. 2a shows a perspective view of the movable coupling half of the coupling device according to the invention. Fig. 1 ; Fig. 3 a top view of the coupling device according to Fig. 1 in axial direction; Fig. 4 a perspective view of the coupling device according to Fig. 1 without the movable coupling half; Fig. 5 a cross-section of a coupling device according to the invention in a further embodiment along the axis of rotation of the coupling device in the closed state; Fig. 6 a schematic sectional view of a bottom bracket gear system for a bicycle with electric auxiliary drive and with four coupling devices according to the invention.

[0089] The Figs. 1 to 4 show the same embodiment of a coupling device 1 according to the invention in the form of an axial claw coupling.

[0090] Fig. 1 Figure 1 shows a cross-section through a coupling device 1 according to the invention along the axis of rotation R of the coupling device. This device has a movable coupling half 2, which is mounted on a shaft 4 by means of an internal splined connection 16 (see Figure 1). Fig. 2 ) in the movable coupling half 2 and a corresponding external splined connection 17 on the shaft 4 (see Fig. 4 ) is axially displaceable, but rotationally fixed. The axial range in which the movable coupling half 2 can be displaced on the shaft 4 is limited by two retaining rings 24.

[0091] Furthermore, the coupling device 1 has a fixed coupling half 3, which is rotationally fixed, in the exemplary embodiment integrally, to a gear 5. The gear 5 in turn is in meshing engagement with another gear 30 (see Fig. 3 ) and forms part of a gearbox for a bicycle. The fixed clutch half 3 is rotatably mounted on the shaft 4 by a bearing, in particular a plain bearing (not shown). Axial movement of the fixed clutch half 3 on the shaft 4 is prevented by two retaining rings 24, 25, with the retaining ring 24 simultaneously limiting the displacement of the movable clutch half 2 in the direction of the fixed clutch half 3.

[0092] The movable coupling half 2 is pressed against the fixed coupling half 3 by a spring 30, so that the coupling device 1 is closed in the rest state.

[0093] The coupling device 1 is designed to selectively transmit a torque from the shaft 4 via the movable coupling half 2 to the fixed coupling half 3 and thus to the gear 5.

[0094] The torque transmission is effected by a face gear 22 on the movable coupling half 2 (see Fig. 2 ) and a corresponding face gear 23 on the fixed coupling half 3 (see Fig. 4 ). The teeth of the face teeth 22, 23 act as claws which can engage axially with each other by an axial displacement of the movable coupling half 2 in the direction of the fixed coupling half 3.

[0095] The side surfaces of the teeth of the face gears 22, 23, which come into contact with each other in a direction of rotation which corresponds to the drive direction in the gearbox, are arranged straight or almost straight, i.e. they lie in a radial plane through the axis of rotation of the movable coupling half 2 or the fixed coupling half 3, so that the torque transmission takes place orthogonally to these side surfaces.

[0096] The side surfaces of the teeth of the spur gears 22, 23, which come into contact with each other in the opposite direction of rotation, the non-drive direction, are steeply inclined relative to the aforementioned radial plane. This allows them to slip against each other when the movable coupling half 2 is subjected to a torque in the non-drive direction. Due to the action of the wedge mechanism formed by these side surfaces of the spur gears 22, 23, the movable coupling half 2 is displaced away from the fixed coupling half 3 against the force of the spring that presses it against the fixed coupling half 3, thus preventing the transmission of torque in the non-drive direction.

[0097] In this way, a freewheel function is implemented in the non-drive direction. This may be necessary to prevent the transmission from locking up during gear changes when several clutches are briefly engaged simultaneously. The freewheel function may also be required to decouple the transmission, or parts of it, from drive components such as an electric auxiliary motor in the non-drive direction. Furthermore, such a freewheel function ensures that the cyclist can stop pedaling in any riding situation. This is an important safety feature, especially in the event of malfunctions in the transmission or the electric auxiliary drive.

[0098] Radially immediately outside the face teeth 22, through holes 18 are arranged distributed around the circumference of the movable coupling half 2, which allow the flow of oil and thus ensure lubrication and cooling of the coupling device 1 at all points between the movable coupling half 2 and the fixed coupling half 3.

[0099] As in Fig. 1 As can be seen, the movable coupling half 2 has a larger radius than the fixed coupling half 3 or the gear 5, so that the radially outer region of the movable coupling half 2 is freely accessible on the axial side facing the fixed coupling half 3. In this radially outer region of the movable coupling half 2, several cam surfaces with respective sections 10 to 14 are arranged, which, in conjunction with associated cam followers 6, allow the coupling device 1 to be opened.

[0100] In this embodiment, each cam follower 6 is implemented as a hemispherical pressure piece, which is arranged at the outer end of a lever arm 27 of a lever 19 such that the apex of the hemisphere, which serves as the pressure point on the cam surface, is located on one side of the plane in which the lever 19 pivots and is directed away from this side. The lever 19 is pivotable about a lever bearing 26 such that the cam follower 6 can be pivoted radially outwards into the cam surfaces (see Fig. 3 and 4 ).

[0101] On the side of the lever arm 27 opposite the cam follower 6, with respect to the plane in which the lever 19 pivots, the lever arm 27 rests against a support 7, which prevents axial displacement of the lever arm 27 and the cam follower 6 towards the fixed coupling half 3. For this purpose, the support 7 has a bearing surface 8 for the cam follower 6, along which the side of the lever arm 27 opposite the cam follower 6 slides radially when the lever 19 pivots. The outermost radial position of the cam follower 6, in which the cam follower 6 is completely pivoted out of the area of ​​the cam surface of the movable coupling half 2, is determined by a stop surface 9 in the support 7.

[0102] In another one, here in Fig. 5In the illustrated embodiment of the coupling device according to the invention, the abutment surface for the cam follower 6 can also be arranged on a rotating component, such as the gear 5. The coupling device in Fig. 5 corresponds to that in Fig. 1 , wherein the gear 5 has a larger diameter. The rotating abutment surface 31 for the cam follower 6 is formed by a side surface of the gear 5.

[0103] Eight identically designed cam surfaces are arranged around the radial outer circumference of the movable coupling half 2, seamlessly connecting to one another in the circumferential direction. Each cam surface has several sub-sections, namely a base area 10, which runs along the outer radial edge of the movable coupling half 2 in the form of a narrow track and has a constant axial level in the circumferential direction; a first circumferential section 11, which also runs along the outer radial edge of the movable coupling half 2 in the form of a narrow track and adjoins the base area 10 in the circumferential direction, with a curvature in the axial direction towards the fixed coupling half 3 and simultaneously a slight pivoting radially inwards; a second circumferential section 12, which adjoins the first circumferential section 11 in the form of a short section in the circumferential direction and has a constant level in the axial direction; a third circumferential section 13,which forms the radially outer end face of the movable coupling half 2 in the area of ​​the first circumferential section 11 and the second circumferential section 12 and has a slight radial inward inclination towards the second circumferential section 12, a radial section 14 which extends radially inside and laterally adjacent to the base area 10 and to the first circumferential section 11 and adjoins them and is thereby curved or arched axially radially inward towards the fixed coupling half 3, so that the radial section 14 reaches the same axial level as the second circumferential section 12 at its radially inner edge.

[0104] Radially within the second circumferential section 12 and the radial section 14 of the cam surface, an annular, continuous and closed open-holding surface 15 extends over the circumference of the movable coupling half 2, which everywhere has the same axial level as the second circumferential section 12 and the radially inner edge of the radial section 14.

[0105] Due to the geometry of the cam surface and the open surface 15 described above, the following possible movement paths B1 to B3 result for the cam follower 6 as soon as it is pivoted radially outside into the area of ​​the cam surface (see Fig. 2 ): Movement path B1:When no or only a small operating torque is applied to the movable coupling half 2, and consequently only small frictional forces act between the spur gears 22, 23, the cam follower 6 is pressed further radially inward onto the radial section 14 by the lever arm 27 as it pivots from radially outward into the base region 10 of the cam surface. The hemispherical cam follower 6 and the radial section 14 interact in the form of a wedge gear. Since the cam follower 6 cannot move axially due to the support of the lever arm 27 on the abutment surface 8 of the support 7, the entire movable coupling half 2 is displaced axially away from the fixed coupling half 3 due to the axial curvature or bulge of the radial section 14. This disengages the spur gears 22, 23, and the coupling device 1 opens.The cam follower 6 is pushed further radially inwards by the lever arm 27, finally reaching the open-holding surface 15 and rotating on it. Since the open-holding surface 15 is continuous in the circumferential direction and has a constant axial level, the coupling device 1 can, in principle, be held open in any length of time.

[0106] Movement path B2:If a significant operating torque is applied to the movable coupling half 2, and correspondingly greater frictional forces act between the face teeth 22, 23, the cam follower 6 cannot be pushed further radially inward onto the radial section 14 by the lever 19 when pivoting from radially outward into the base region 10 of the cam surface, as the actuating force of the lever 19 is insufficient. The cam follower 6 thus remains in the base region 10 and is guided onto the first circumferential section 11 by the rotation of the movable coupling half 2. In this case, the hemispherical cam follower 6 and the first circumferential section 11 interact in the form of a wedge gear. Due to the axial curvature of the first circumferential section 11, the entire movable coupling half 2 is displaced axially away from the fixed coupling half 3, and the coupling device 1 opens.The opening force generated is produced by the operating torque and is therefore correspondingly greater than the opening force in the case of the motion path B1 described above. This opening force is also sufficient to overcome the greater frictional forces between the face gears 22 and 23. Following the direction of the first circumferential section 11, the cam follower 6 is simultaneously pivoted slightly radially inward under the action of the lever 19. The cam follower 6 then reaches the second circumferential section 12, is pushed further radially inward by the lever 19, and finally comes to rest on the open surface 15 with the effect described above for motion path B1.

[0107] Movement path B3:Depending on the rotational position of the movable coupling half 2, the cam follower 6, when pivoting radially outwards, may engage the third circumferential section 13 instead of the base area 10 of the cam surface. In this case, the cam follower 6 and the third circumferential section 13 interact in the form of a wedge gear. If no or only a small operating torque is applied to the movable coupling half 2, the cam follower 6 is immediately pivoted radially inwards by the lever 19 onto the second circumferential section 12, and the movable coupling half 2 moves axially away from the fixed coupling half 3.With a higher applied operating torque and correspondingly higher frictional forces between the face teeth 22, 23, the cam follower 6 cannot move radially inwards on the third circumferential section 13 solely by the actuating force of the lever 19, but must first "wait" until it reaches the base area 10 of the cam surface due to the rotation of the movable coupling half 2. It will then move further along the path of motion B2, as described above.

[0108] Thus, each of the movement paths B1, B2 and B3 causes the clutch device 1 to open, depending on the magnitude of the applied operating torque.

[0109] From the respective sections 10 to 14 of the cam surfaces, on which the cam follower 6 moves according to the motion paths B1 to B3, it is further evident that the coupling device 1 in the exemplary embodiment has two cam surfaces: The first cam surface comprises the base area 10, the first circumferential section 11 and the second circumferential section 12 and extends essentially in the circumferential direction of the movable coupling half 2. The second cam surface comprises the base area 10 and the radial section 14 and extends essentially in the radial direction of the movable coupling half 2. The first and the second cam surfaces are thus partially identical in that they both comprise the base area 10.

[0110] The Fig. 3 and 4The illustrations show the operation of the lever 19 in various ways. As already mentioned, the lever 19 can be pivoted about a lever bearing 26 in such a way that the cam follower 6 arranged at the end of the lever arm 27 is pivoted radially outside into or out of the cam surface of the movable coupling half 2.

[0111] For this purpose, the lever 19 has two lever arms 28, 29 arranged orthogonally to the lever arm 27. The inner lever arm 28 can be pressed radially inwards by an actuating device 21, the operation of which is not described in detail here, causing the lever arm 27 to move radially outwards. Furthermore, the outer lever arm 29 is biased by a tension spring 20 such that the lever arm 27 is pre-tensioned radially inwards.

[0112] When the actuating device 21 is not active, the cam follower 6 is always pressed radially inwards, which, as described above, opens the coupling device 1 and holds it in the open position. The coupling device 1 is therefore open in its resting state.

[0113] To close the coupling device 1, the actuating device 21 is actuated, causing the inner lever arm 28 to pivot radially inwards and thus the lever arm 27 and the cam follower 6 to pivot radially outwards. Due to the load on the movable coupling half 2 by the spring 30 in the direction of the fixed coupling half 3, the movable coupling half 2 then moves axially in the direction of the fixed coupling half 3, the face teeth 22, 23 engage and the coupling device 1 is closed.

[0114] The face gears 22, 23 are preferably designed as self-locking jaw couplings. This allows the operating torque to be reliably transmitted from the shaft 4 to the gear 5. In this state, i.e., with the coupling device closed, the cam follower 6 is preferably not in contact with rotating components.

[0115] Fig. 3 The coupling device 1 is shown in a top view parallel to plane AB, which is in Fig. 1 is defined. The movable coupling half 2 is located behind the fixed coupling half 3, which is not visibly attached to the gear 5. The movable coupling half 2 has an internal splined connection 16 and can therefore, while simultaneously being axially displaceable, transmit torques to the external splined connection 17 of the shaft 4 (see Fig. 4) transmitted. The gear 5 is rotatably mounted on the shaft 4 and meshes with the gear 5'. When the coupling device 1 is closed, the movable coupling half 2 forms a positive connection with the fixed coupling half 3 arranged on the gear 5.

[0116] With the coupling device 1 open, the two cam followers 6 run on the hold-open surface 15 and keep the coupling device 1 open. (Shown in dashed lines) Fig. 3 The cam followers 6 are in the swung-out position, and the coupling device 1 can transmit torque in this position. The cam followers 6 are not located radially in a cylindrical area. the base area 10 of the backdrop surface, the first, second and third circumferential sections 11, 12, 13 of the backdrop surface, the radial section 14 of the backdrop surface and the open area 15 The surfaces 11, 13 and 14, together with the cam follower 6, each form a wedge gear in the sense defined above.

[0117] The relative position of the cam follower 6 to the cam surfaces and the open surface 15, and thus also to the other surface of the wedge gear, can be changed by means of the actuating device 21 and via the inner lever arm 28 of the lever 19, in order to effect a change of state of the coupling device 1. The change in position of the cam follower 6 is effected by a spring 20, the spring 20 being under the greatest tension when the cam follower 6 is radially outside the movable coupling half 2, and under the least tension when the cam follower 6 is in contact with the open surface 15.

[0118] In an advantageous embodiment, the forces acting on the cam followers 6 during the opening process can be transferred into the frame of the gearbox via a support surface 8 located on a support 7.

[0119] The position of the cam follower 6 can be changed by different mechanisms. The exemplary implementation in Fig. 3 Figure 1 shows the radial change in position of the cam follower 6, which is rigidly connected to the lever arm 27 of the lever 19. One end of the tension spring 20 is fixed to the frame, and the other end of the tension spring 20 is attached to the outer lever arm 29 and causes the cam follower 6 to always pivot radially inwards towards the open surface 15 when the actuating device 21 is not engaged. In this way, the energy stored in the spring 20 is used to allow the cam follower 6 to slide radially over the surfaces of the wedge gear.

[0120] The circumferential movement of the cam follower 6 over the wedge gear surfaces is caused by the rotation of the shaft 4 and the movable coupling half 2. The orientation of the inclinations and curvatures of the wedge gear surfaces in space is chosen such that parts of the mechanical work transmitted via the coupling device 1 or via the gearbox are used to open the coupling device 1.

[0121] Fig. 6 Figure 1 shows a schematic sectional view of a bottom bracket circuit with electric auxiliary drive 40 and with four coupling devices 1 according to the present invention.

[0122] The rider's pedaling power is transmitted via the pedal arms 33 to the bottom bracket axle 32. The output hollow shaft 38 is supported in the housing 42 by ball bearings 36. An input hollow shaft 37 is equipped with two gear pairs 5a, 5b and 5c, 5d and runs coaxially to the bottom bracket axle 32. The rider's torque is transmitted from the bottom bracket axle 32 to the input hollow shaft 37 via a freewheel 34. A sensor 35 is located between the bottom bracket axle 32 and the input hollow shaft 37 and records the values ​​relevant for motor control, such as speed, torque, and angle of rotation. The schematically depicted electric auxiliary drive 40 drives the coupling gear 43 via a gearbox 41. The torque is transmitted from the input hollow shaft 37 via the gears 5a and 5c and the associated gears 5b, 5d and from there selectively via a coupling device 1 according to the invention to the shaft 4.

[0123] In the exemplary design according to Fig. 6 Two gear stages A and B together form a first sub-gearbox TG1 with two gear stages. Two clutch devices 1 according to the invention are located in the first sub-gearbox TG1.

[0124] When the term "sub-transmission" is used here, it refers to a sub-assembly within a transmission that provides at least two different gear ratios. A sub-transmission can be a switchable spur gear transmission, a switchable planetary gear transmission, or another type of transmission.

[0125] A second sub-gearbox TG2 with gear stages C and D is also located on shaft 4 in the illustration on the right and transmits the torque from shaft 4 via further gear pairs 5e, 5f and 5g, 5h to the output hollow shaft 38.

[0126] The output hollow shaft 38 is mounted on the housing 42 and on the bottom bracket shaft 32 via ball bearings 36 and runs coaxially to the bottom bracket shaft 32. The output hollow shaft 38 transmits the torque to the output sprocket 39, which drives the driven wheel of the vehicle via a traction element (not shown), for example a chain or a belt.

[0127] The gear stages A, B, C, and D are implemented here as spur gear drives. In this example configuration, the first sub-transmission TG1 has two gears, and the second sub-transmission TG2 also has two gears. Since the two sub-transmissions TG1 and TG2 are connected in series, the total number of gears is 2 x 2 = 4 gear stages.

[0128] Other exemplary embodiments of manual transmissions with the clutch device according to the invention, not shown here, have more than two gear stages in each sub-transmission. If, for example, the first sub-transmission has four gear stages and the second sub-transmission has three gear stages, the total number of possible gears would be twelve.

[0129] In Fig. 6The gears 5b, 5d, 5f, and 5h are mounted as loose gears on the shaft 4 and axially secured by retaining rings 25, here circlips. Together with the respective spur gears 23, they form the fixed coupling halves 3. The movable coupling halves 2 are connected to the shaft 4 via internal and external splined connections 16, 17 and can thus transmit torque. Nevertheless, the coupling halves 2 are axially displaceable on the shaft 4 and again have retaining rings 24, here also circlips, and in some cases also retaining rings 25 as axial stops. The compression springs 30 are arranged such that the movable coupling halves 2 are constantly pressed towards the fixed coupling halves 3. When the movable coupling halves 2 are not in contact with the respective follower 6, they are thus closed and activated. The coupling devices 1 of gear stages B and C are in Fig. 6The closed position is shown. The respective cam follower 6 is pulled radially outwards by the respective actuating device 21 and is not in contact with the respective cam surfaces. The respective tension spring 20 is under tension.

[0130] Gear stages A and D, on the other hand, are in a deactivated, open state. The respective cam follower 6 is connected to the respective hold-open surface 15. The respective spring 30 cannot close the respective clutch assembly 1, since the respective movable clutch half 2 is supported on the housing 42 via the respective cam follower 6 and the respective abutment surface 8.

[0131] One can recognize in Fig. 6 , that an advantageous design results within a transmission system if each sub-transmission TG1, TG2 contains at least two clutch devices 1.

[0132] A large number of gear stages can be achieved if at least two sub-transmissions TG1, TG2 are connected in series, each sub-transmission TG1, TG2 containing at least two clutch devices 1 according to the invention.

[0133] A particularly lightweight and space-saving design is achieved when at least two sub-gearboxes TG1, TG2 with the coupling devices 1 according to the invention are arranged coaxially to each other.

[0134] Thus, preferably two and more preferably four or more than four coupling devices 1 are arranged coaxially to each other.

[0135] The shifting process from one gear stage to another is particularly safe and can be carried out without neutral if the engagement process of a first clutch device 1 is carried out before the disengagement process of a second clutch device 1 within the same sub-transmission TG1, TG2.

[0136] The shifting process from one gear stage to another is therefore particularly safe and can be carried out without neutral if, during the shifting process, there is a point in time or period at which the movable clutch halves 2 are engaged with the fixed clutch halves 3 of two clutch devices 1.

[0137] Deactivating a coupling device 1 is particularly simple, trouble-free, and requires minimal energy and control effort within the actuating device 21 if the cam follower 6 is moved relative to the cam surfaces 10-14 and / or to the open surface 15 by means of a spring 20. When deactivation is mentioned here, it refers to the process that brings the coupling device 1 into a state in which it can no longer transmit torque, i.e., the opening of the coupling. Reference symbol list

[0138] 1 Coupling device 2 Movable coupling half 3 Fixed coupling half 4 Shaft 5, 5' Gear 5a-h Gear 6 Cam follower 7 Support 8 Abutment surface for cam follower 9 Stop surface for cam follower 10 Base of cam surface 11 First circumferential section of cam surface 12 Second circumferential section of cam surface 13 Third circumferential section of cam surface 14 Radial section of cam surface 15 Open surface 16 Inner splined connection 17 Outer splined connection 18 Through hole 19 Lever 20 Tension spring 21 Actuating device 22 Spur gearing on the movable coupling half 23 Spur gearing on the fixed coupling half 24, 25 Retaining ring 26 Lever bearing 27 Lever arm 28 Inner lever arm 29 Outer lever arm 30 SpringCompression spring 31 Rotating support surface for cam follower 32 Bottom bracket shaft 33 Pedal arm 34 Bottom bracket freewheel 35 Sensor 36 Ball bearing 37 Input hollow shaft 38 Output hollow shaft 39 Output pinion 40 Electric auxiliary drive 41 Gearbox 42 Housing 43 Coupling gear R Rotation axis B1-B3 Motion path A First gear ratio B Second gear ratio C Third gear ratio D Fourth gear ratio TG1 First sub-gearbox TG2 Second sub-gearbox

Claims

1. A clutch device (1) for selective transmission of a torque from a first shaft or hub (4) to a second shaft or hub (5), in particular for a gear-shifting system for a bicycle, having - a first clutch half (2) connected to the first shaft or hub (4) in a rotationally fixed manner, - a second clutch half (3) connected to the second shaft or hub (5) in a rotationally fixed manner, - a first opening device (6-12, 15) adapted to generate, from an operating torque with which the first clutch half (2) is supplied, in particular by means of an operation of a bicycle with a gear-shifting system containing the clutch device (1), a first opening force by means of which the clutch device (1) is transitionable from a closed state, in which a torque is transmittable from the first clutch half (2) to the second clutch half (3), to an opened state, in which no torque is transmittable from the first clutch half (2) to the second clutch half (3), and - an actuating device (21) adapted for controlling the first opening device (6-12, 15), wherein the first opening device (6-12, 15) is arranged spatially separated from the torque transmission region (22-23) of the clutch device (1), i.e., from that spatial region at which, in the closed state of the clutch device (1), a torque transmission from the first clutch half (2) to the second clutch half (3) may take place, characterized by a second opening device (6-10, 12-15) adapted to generate, without use of the operating torque, a second opening force by means of which the clutch device (1) is transitionable from the closed state to the opened state, wherein the actuating device (21) is adapted for controlling the second opening device (6-10, 12-15), and wherein an operating torque at which the second opening device (6-10, 12-15) is effective is less than an operating torque at which the first opening device (6-12, 15) is effective.

2. The clutch device (1) according to claim 1, characterized in that the first opening device (6-12, 15) is arranged radially further outwards than the torque transmission region (22-23).

3. The clutch device (1) according to any one of the preceding claims, characterized in that a movable clutch half (2) which is one of the first clutch half (2) and the second clutch half (3) is movable in an axial direction of the first shaft or hub (4) or the second shaft or hub (5), respectively, and in that the first opening device (6-12, 15) has: - at least one first link surface (10-12) arranged on the movable clutch half (2), extending in a first direction of extension substantially in a circumferential direction of the movable clutch half (2) and having such a first curvature that a position changes in an axial direction of a point on the first link surface (10-12) along the first direction of extension, and - at least one first link follower (6) adapted to contact the first link surface (10-12) along the first direction of extension upon rotation of the movable clutch half (2), thereby to generate the first opening force and thereby to effect a movement of the movable clutch half (2) in the axial direction, whereby the clutch device (1) is transitioned from the closed state to the opened state, wherein the actuating device (21) is adapted to engage the at least one first link follower (6) with the first link surface (10-12) and to disengage it from the first link surface (10-12).

4. The clutch device (1) according to claim 3, characterized in that at least one first link surface (11) and the at least one first link follower (6) together form a wedge gear set.

5. The clutch device (1) according to any one of claims 3 to 4, characterized in that the first opening device (6-12, 15) furthermore has a first hold-open surface (15) arranged on the movable clutch half (2) such that the clutch device (1) is in the opened state upon contacting the first hold-open surface (15) by the at least one first link follower (6), wherein the first hold-open surface (15) is arranged adjacent to a region of the first link surface (10-12) upon contacting of which by the at least one first link follower (6) the clutch device (1) is in the opened state.

6. The clutch device (1) according to any one of claims 3 to 5, characterized in that the at least one first link follower (6), by means of a movement of the at least one first link follower (6) in the radial direction of the movable clutch half (2), in particular by a lever or slider mechanism (19), is engageable with the at least one first link surface (10-12) and / or disengageable from the at least one first link surface (10-12).

7. The clutch device (1) according to claim 6, characterized in that the movement of the at least one first link follower (6) in the radial direction of the movable clutch half (2) upon engaging the at least one first link surface (10-12) is at least partially effected by a spring (20), in particular by releasing the spring (20).

8. The clutch device (1) according to any one of claims 3 to 7, characterized in that the first opening device (6-12, 15) has a plurality of first link surfaces (10-12) arranged along the circumferential direction of the movable clutch half (2).

9. The clutch device (1) according to any one of claims 3 to 8, characterized in that the first opening device (6-12, 15) has a plurality of first link followers (6) arranged along the circumferential direction of the movable clutch half (2).

10. The clutch device (1) according to any one of the preceding claims, characterized in that the second opening device (6-10, 12-15) is arranged radially further outwards than the torque transmission region (22-23).

11. The clutch device (1) according to any one of the preceding claims, characterized in that the second opening device (6-10, 12-15) has: - at least one second link surface (10, 12-15) arranged on the movable clutch half (2), extending in a second direction of extension substantially in a radial direction of the movable clutch half (2) and having such a second curvature that a position changes in an axial direction of a point on the at least one second link surface (10, 12-15) along the second direction of extension, and - at least one second link follower (6) adapted to contact the at least one second link surface (10, 12-15) along the second direction of extension, thereby to generate the second opening force and thereby to effect a movement of the movable clutch half (2) in the axial direction, whereby the clutch device (1) is transitioned from the closed state to the opened state, wherein the actuating device (21) is adapted to engage the at least one second link follower (6) with the at least one second link surface (10, 12-15), to move it along the second direction of extension and to disengage it from the second link surface (10, 12-15).

12. The clutch device (1) according to claim 11, characterized in that at least one second link surface (14) and the at least one second link follower (6) together form a wedge gear set.

13. The clutch device (1) according to any one of claims 11 to 12, characterized in that the at least one second link surface (10, 12-15) has a second hold-open surface (15), wherein the clutch device (1) is in the opened state upon contacting the second hold-open surface (15) by the at least one second link follower (6).

14. The clutch device (1) according to any one of claims 11 to 13, characterized in that the at least one second link follower (6), by means of a movement of the at least one second link follower (6) in the radial direction of the movable clutch half (2), in particular by a lever or slider mechanism (19), is engageable with the second link surface (10, 12-15) and / or disengageable from the second link surface (10, 12-15).

15. The clutch device (1) according to claim 14, characterized in that the movement of the at least one second link follower (6) in the radial direction of the movable clutch half (2) upon engaging the second link surface (10, 12-15) and / or the movement of the at least one second link follower (6) along the second direction of extension is at least partially effected by a spring (20), in particular by releasing the spring (20).

16. The clutch device (1) according to at least one of claims 11 to 15, characterized in that the second opening device (6-10, 12-15) has a plurality of second link surfaces (10, 12-15) arranged along the circumferential direction of the movable clutch half (2).

17. The clutch device (1) according to at least one of claims 11 to 16, characterized in that the second opening device (6-10, 12-15) has a plurality of second link followers (6) arranged along the circumferential direction of the movable clutch half (2).

18. The clutch device (1) according to any one of claims 3 to 9 and any one of claims 11 to 17, characterized in that the at least one first link surface (10-12) is at least partially identical to the at least one second link surface (10, 12-15), and / or in that the at least one first link follower (6) is substantially identical to the at least one second link follower (6).

19. The clutch device (1) according to claims 5, 13 and 18, characterized in that the first hold-open surface (15) is substantially identical to the second hold-open surface (15).

20. A gear-shifting system for a bicycle with at least one clutch device (1) according to any one of the preceding claims.