DE102018133324A1 - Rear sprocket assembly with two integral partial assemblies interconnected for common rotation - Google Patents

Abstract

A bicycle rear sprocket assembly (30) which is rotatable about a common pinion axis of rotation (RA) defining an axial direction and orthogonal thereto radial directions comprises a plurality of coaxially arranged with respect to the pinion axis of rotation (RA) for common rotation about the pinion axis of rotation (RA) interconnected pinions (R1-R12) of different size and number of teeth, wherein the pinion assembly (30) comprises a first subassembly (32) comprising the largest sprocket (R1) and a second subassembly (34) comprising a plurality of one piece formed with each other pinions (R3-R12).
According to the invention, a subassembly (34) comprising first and second subassemblies (32, 34) has a plurality of elastically deformable latching formations (60c) which engage in latching engagement with a plurality of latching counterforms (40) of the respective other subassembly (32) wherein the latching engagement secures the two subassemblies (32, 34) against removal in the axial direction.

Description

The present invention relates to a bicycle rear sprocket assembly which is rotatable about a pinion rotation axis. The pinion rotation axis defines an axial direction and orthogonal thereto radial directions. The pinion rotation axis also defines a circumferential direction around it. The rear wheel sprocket assembly includes a plurality of pinions of different size and number of teeth disposed coaxially with respect to the pinion axis of rotation for conjoint rotation around the pinion axis, the pinion assembly comprising a first subassembly comprising the largest pinion and a second subassembly comprising a plurality of one piece formed with each other pinions.

The present invention further relates to a bicycle drive assembly comprising a bicycle chain and a bicycle rear wheel sprocket assembly engageable with the bicycle chain in driving force to transmit positive locking engagement. The bicycle chain has in a conventional manner along its chain longitudinal direction alternately by outer and inner strap pairings interconnected roles. The rear wheel sprocket assembly is constructed as described in the present application.

A generic bicycle rear sprocket assembly, so as described in the first paragraph, is from the DE 10 2015 205 736 A1 known. From this document, a generic bicycle drive assembly is known, as described in the second paragraph.

The from the DE 10 2015 205 736 A1 Known rear sprocket arrangement has a very large spread, so a very large difference in the number of teeth between the smallest and the largest pinion on. As a result, the diameters of the smallest and the largest pinion are very different. The largest sprocket is therefore subject to considerable mechanical stress when the bicycle chain is engaged with the largest sprocket. Due to an inclination of the standing with the largest pinion gear chain chain relative to a pinion axis orthogonal Fahrradlängsmittelebene the largest pinion is loaded by the bicycle chain on its radially outer ring gear not only with forces in the circumferential direction, but also with forces acting in the axial direction, the due to their force application on the gear ring remote from the pinion axis of rotation radially, a significant bending effect about a bending axis orthogonal to the pinion axis of rotation can take place.

The from the DE 10 2015 205 736 A1 known pinion assembly has a first subassembly, which comprises only the largest pinion, and has a second sub-assembly connected thereto, which has as a one-piece pinion gear all the other sprockets from the second largest to the smallest sprocket. Mounting pins projecting axially from the pinion dome penetrate fastening openings in fastening surfaces of the first subassembly, which are designed specifically for this purpose on the first subassembly. The attachment surfaces thereby span a pair of circumferentially adjacent pinion spokes of the first subassembly to provide sufficient material for forming the attachment apertures.

The mounting pins are made with respect to the mounting holes with oversize. The mounting pins are press-fitted into the mounting holes. By abrupt axial deformation of their free longitudinal end towards the second sub-assembly having them, the longitudinal end portions of the fixing pins inserted into the fixing holes are radially widened ("mushroomed") so that in addition to the press fit, a positive locking action is added to the second subassembly on the first subassembly holds. The two subassemblies are thus insoluble, d. H. not separable without destruction of components or component sections, connected together.

However, it has been found that the weakening of the attachment surfaces by the attachment holes penetrating them in the thickness direction with the mushroom attachment pins formed therein results in stress peaks and thus crack formation and / or similar damage formation in view of the forces and moments acting on the pinion assembly during operation can.

It is therefore an object of the present invention to increase the mechanical strength of the aforementioned pinion arrangement, so that it has a higher stability than the known sprocket arrangement of the prior art during normal operation.

This object is achieved in that a subassembly of the first and second subassembly has a plurality of elastically deformable Verrastungsformationen, which are in engagement engagement with a plurality of Verrastungsgegenformationen the other subassembly, wherein the Verrastungseingriff the two sub-assemblies against removal from each other in the axial direction guaranteed.

The term "locking" is in this case a form-fitting engagement referred to, which, taking advantage of the material and component elasticity of Verrastungsformationen, possibly also the Verrastungsgegenformationen, by elastic deformation of the formations can be produced. The latching is thus to be distinguished from a connection of the first and the second subassembly by screwing or by bayonet closure, in which no formation involved in an engagement allows this engagement only by interim elastic deformation of the formation.

By locking the two sub-assemblies with each other, these are connected to each other for the transmission of forces acting along the pinion axis of rotation. The axial forces which occur during normal operation of the pinion arrangement are caused by the chain skew, which is the greater, the more pinions the rear wheel pinion arrangement has and the more chainrings are provided on the pedal crank. The axial forces acting on a rear wheel sprocket assembly during normal operation are not negligible and should not be underestimated.

The Verrastungsformationen and Verrastungsgegenformationen can be formed without weakening of a component portion, such as by material removal as in the known attachment opening on the respective sub-assemblies.

The latching engagement between the first and second subassemblies also allows the first and second subassemblies to be interconnected, free of connecting means separate from the first and second subassemblies, such as bolts, nuts, rivets, which not only reduces the assembly effort of the sprocket assembly, but also increases the component strength, since no abutment formations for separate connection means must be provided.

In principle, it may be considered that at least one group of formations of latching formations and latching counterformations is formed on a corresponding latching or latching counterpart component which is mounted on the first or / and the second subassembly. Preferably, the pinion assembly according to the invention comes from reasons as high as component strength with as few mounting points and components as possible. Therefore, it is preferred if the Verrastungsformationen and / or the Verrastungsgegenformationen are formed integrally with the subassembly each having them. Preferably, both formations are integrally formed in each case with the subassembly having them.

Such a one-piece design even with complicated shapes of the sub-assemblies involved can be achieved by a multi-stage processing method, which includes a ur- and / or reshaping earlier processing phase and a cutting later processing phase. Thus, for example, first a component blank for the respective subassembly can be cast or / and forged before the component blank thus obtained receives its final shape by machining, such as turning and milling.

The latching engagement should define the two components involved: first and second subassembly relative to one another not only axially, but preferably also radially and in the circumferential direction in at least one direction. This can be achieved in a simple but effective manner, characterized in that the Verrastungsformationen have axially projecting from the partial arrangement having axial projections. Depending on their orientation and configuration, the axial projections can serve as mechanical stops in an axial direction and preferably also in a direction orthogonal to the pinion rotational axis and thus prevent a relative movement of the first and the second subassembly in the axial direction and preferably also in the direction orthogonal to the pinion axis of rotation.

For the axial fixation of the first and the second subassembly relative to one another it can be provided that the axial projections as axial fixing projections with an axial distance from a root region, from which the axial projections project from the subassembly having them, in the circumferential direction about the pinion axis of rotation and / or Has in the radial direction of the respective axial projection protruding locking lug. The locking lug can then engage behind a corresponding Verrastungsgegenformation and so limit an axial relative movement of the first and the second subassembly in at least one axial direction.

Preferably, the Axial-Fixiervorsprünge in a direction orthogonal to the pinion axis of rotation, ie in the radial direction and / or in the circumferential direction, deformable, preferably with respect to their root area, from which they cantilever bend. In the axial direction, they are preferably rigid in order to provide high securing forces in the axial direction can.

An axial fixing projection can even completely prevent an axial relative movement between the first and the second subassembly and thus sufficiently clearly define the two subassemblies axially relative to one another when the axial fixing projection holds a fixing portion of a detent counter formation in a retaining space axially defined, which axially in one First direction is limited by the locking lug and in one of the first opposite second direction by an axially spaced therefrom, extending parallel to the locking lug retaining formation. The holding formation can be any formation. Preferably, it is the already existing root area, from which the axial fixing projection projects axially away from the subassembly carrying it. Thus, for example, an outer surface of the root area indicative of the latching nose can form a contact surface on which the fixing section of the associated latching counter-formation, which is secured against lifting by the latching lug, rests. Preferably, a plurality of Axial-Fixiervorsprüngen, more preferably all Axial-Fixiervorsprünge are designed such that they provide the above-mentioned holding space.

In order to fix the first and the second subassembly relative to one another in the radial and / or circumferential direction, it may further be provided that the first and / or the second subassembly has axial projections as stop projections with a stop surface which points in an effective direction with a course component orthogonal to the pinion axis of rotation and at which a respective abutment portion of a stop counter-formation is applied. Depending on whether a stop projection is intended to prevent a relative movement of the two subassemblies in the radial or circumferential direction, the effective direction is a radial direction or a circumferential direction. Preferably, the direction of action has running components both in the radial direction and in the circumferential direction, so that a stop projection can obstruct or limit a relative movement of the two partial arrangements both in the radial direction and in the circumferential direction. In principle, it should not be ruled out that the direction of action also has a course component in the axial direction; however, the course components of the effective direction are preferably exclusively orthogonal to the pinion rotation axis. As a result, axial force effects on the stop projections are avoided, which would otherwise act on the two sub-assemblies.

In order to make the sub-assemblies structurally as simple as possible, at least part of the stop projections, preferably all stop projections, are formed on the same sub-assembly as the latching formations, in particular the axial fixing projections. In this case, the abutment projection which is in abutting engagement with a stop projection is preferably a detent counterpart. The effective directions of abutment projections situated at different locations of a partial arrangement preferably have local directions in different directions, each of which has a profile component orthogonal to the pinion axis of rotation or orthogonal to the pinion axis of rotation.

So that a relative movement of the two subassemblies can be prevented not only in a radial direction and / or not only in a circumferential direction, at least one of the subassemblies preferably has counter-abutment projections with a counter-abutment surface facing in a counteracting direction with a course component orthogonal to the pinion axis of rotation and at which depending abgegenanschlagabschnitt a stop mating formation is present. In this case, the radial gradient components and / or the course components in the circumferential direction of the direction of action and counter-acting direction of abutting one and the same abutment mating stop surfaces and counter-stop surfaces in opposite directions. Preferably, the counteracting direction without axial component extends only orthogonal to the pinion axis of rotation. Again, the fence counter formation may be a latch counterface.

Also, the counter-abutment projections are preferably effective both in the radial direction and in the circumferential direction. What has been said above regarding the stop projections and their direction of action also applies mutatis mutandis to the counter stop projections and their counteracting direction.

By fixing the first and the second subassembly to one another, the abutment stop and counterstop projections mentioned ensure that the latching engagement once formed can not be released again by relative movement of the subassemblies. The Verrastungseingriff is preferred to increase the reliability of the pinion assembly is a practically insoluble Verrastungseingriff that, for example, because of the large number of Axial Fixiervorsprüngen, which would all be deformed simultaneously, can be solved only with unrealistic high effort again.

Preferably, the joining of first and second subassembly takes place while producing the abovementioned latching engagement by coaxial arrangement of the two subassemblies relative to the common pinion axis of rotation and by exerting force on the two subassemblies in the axial direction, preferably only in the axial direction. This joining, in which the Axial-Fixiervorsprünge be elastically deformed due to the detent lug provided there, can be facilitated by having at least a portion of the counter-abutment projections, preferably all counter-abutment projections, at its cantilevered longitudinal end an inclined surface, wherein the counter-abutment surface axially between the inclined surface and the root portion from which the counter-abutment protrusions protrude. The inclined surface is inclined in such a way that a point migrating axially in the direction of the root region approaches in the radial direction and / or in the circumferential direction of the counter-abutment surface. Counter stop projections are preferably formed on the same subassembly as the axial Fixiervorsprünge and particularly preferably as the stopper projections.

Then, when pairs of abutment and counter stop projections, wherein the Axial-Fixiervorsprünge stopper projections may be arranged such that they in the finished latched state of the sub-assemblies between their stop and counter stop surfaces an abutment counter-formation, optionally in the form of a Verrastungsgegenformation, in one direction hold orthogonal to the pinion axis of play between them, the exercise of exclusively axial joining force on the two sub-assemblies, the inclined surfaces serve during the joining operation as a mechanical forced guidance of the Verrastungsformationen and the Verrastungsgegenformationen in the Verrastungseingriff. The deformation work of the axial joining projections can be reduced by the said inclined surfaces, for example, because the Verrastungsgegenformationen can be screwed along the inclined surfaces in the above-mentioned holding spaces of the Axial-Fixiervorsprünge in a kind rudimentary screwing, whereby the Axial-joining projections less strongly orthogonal to the pinion axis of rotation would have to deform as if they simply by the dimension of their protruding locking lug in the radial direction and / or in the circumferential direction - depending on their design and orientation - should be pushed aside to make the holding space accessible from the purely axial direction.

The number of axial projections required for a secure latching engagement can advantageously be kept low by virtue of the fact that at least part of the axial fixing projections, preferably all axial fixing projections, are also stop projections. An edge of the axial fixing projection situated axially between latching lug and holding formation, in particular root area, is then stop face or at least has such a surface.

Said axial projections are preferably formed on a closed around the pinion axis of rotation of a pinion gear of a pinion of the sub-assembly carrying them and are axially from this sprocket. The axial projections are arranged in the circumferential direction at a distance from each other. Due to the arrangement on the sprocket, the radial distance between different axial projections is smaller than their distance in the circumferential direction from each other.

Axial projections are preferably provided as axial fixing projections, as stop projections and as counter-abutment projections, in order to fix the two subassemblies with respect to their cylindrical coordinate system comprising an axial, a radial and a peripheral coordinate in a clearly positioned relationship with sufficient strength against the forces and moments occurring during operation , To ensure this defined positional determination, the axial projections may form a plurality of projection groups, each of which has at least one axial fixing projection and one counter-abutment projection. This is sufficient if the Axial Fixiervorsprung is also stop projection. At least a part of the projection groups, preferably all projection groups may additionally have a stop projection. Preferably, each projection group, taken alone, secures the two subassemblies relative to one another with respect to a movement along the axial and at least one further cylindrical coordinate, preferably along all three cylindrical coordinates.

By providing a plurality of protrusion groups, the achievable maximum load capacity of the locking engagement achieved by the protrusion groups is increased, however, the attachment of the two sub-assemblies to each other by a plurality of protrusion groups, each of which the two sub-assemblies with respect to the axial direction and another cylindrical coordinate or even with respect to all three linearly independent cylindrical coordinates relative to each other, mechanically overdetermined. However, the effects of mechanical over-determination can be reduced by corresponding elasticities on the latching formations or / and the latching counterformations, since participating formations can reduce stresses due to mechanical over-determination by elastic deformation. It applies the principle that a mechanically loaded component either has internal stresses, then it is not or only slightly deformed, or has deformations, then it has little or no internal stress. Thus, the effect of increased strength of the achievable Verrastungseingriffs with mitigated effect of the mechanical overdetermination remains. The arrangement is thus advantageous overall.

Preferably, the projection groups are identically formed and distributed along the entire circumference of the subassembly having them, particularly preferably distributed equidistant. Incidentally, the use of a plurality of projection groups, such as more than three or four projection groups, ensures the above-mentioned practical insolubility of the locking engagement. While the engagement of a portion of a latching counter formation by a single axial fixing projection can be canceled by corresponding deformation thereof, simultaneous deformation of a plurality of axial fixing protrusions becomes more difficult to virtually impossible as the number increases. Preferably, the locking lugs of different axial fixing projections in different directions are orthogonal to the pinion rotation axis of the respective axial projection. Then, not only a plurality of axial fixing protrusions would have to be deformed to release the locking engagement, but each protrusion of this plurality would be deformed in different directions. This is factually and practically impossible.

Although it should not be ruled out in principle that axial projections, which are involved in the latching engagement, are also arranged on the first subassembly, such axial projections are preferably provided only on the second subassembly.

To avoid unnecessary weight of the sprocket assembly, which must always accelerate and retard the cyclist, it is preferred that a pinion of the first and / or the second subassembly a pinion teeth having radially outer sprocket and a trained for the transmission of torque to the rear hub radially inner Hub region, wherein the hub portion and the sprocket portion are interconnected by means of a plurality of circumferentially spaced pinion spokes. The sprocket area further away from the pinion rotation axis serves, in a manner known per se, to transmit force between a bicycle chain and the sprocket arrangement. The hub region located closer to the pinion rotation axis serves, in a manner known per se, to transmit torque from the pinion arrangement to a rear hub, for example, with an intermediate arrangement of a drive.

The Verrastungsgegenformationen can very efficiently have a plurality of already existing sprocket spokes. In this case, the Verrastungsgegenformationen must not be specially trained.

Since the arrangement of sprocket spokes promises a high weight saving, especially with the larger diameter sprockets, compared to a solid construction of the sprocket, the sprocket spokes and thus the Verrastungsgegenformationen preferably formed on the first subassembly having the largest sprocket of the sprocket assembly ,

In principle, sprocket spokes can run continuously from the hub area to the sprocket area. However, since radius rays emanating from the pinion rotation axis diverge greatly, the occupation of pinion surface by pinion spokes decreases with increasing radial distance from the pinion rotation axis. However, force is introduced into the pinion by the bicycle chain at a maximum radial distance from the pinion rotation axis. Thus, in order to be able to provide sufficient sprocket spokes for transmission of force and a resulting torque between the sprocket area and the hub area even in radially outer areas, according to an advantageous development of the present invention, the sprocket spokes have a smaller number radially further inside located inner sprocket spokes and a larger number of radially outer outer pinion spokes. Since the latching formations of the respective other subassembly which cooperate with the sprocket spokes as the latching counterformations are generally likewise arranged in a sprocket region of the subassembly having the latching formations, the latching formations lie radially more far outward in the most practically relevant cases than further inward. Therefore, preferably, the latch counterformations include outer sprocket spokes. Preferably, the latch counterformations include only outer sprocket spokes.

Also, the abutment stop mentioned above is preferably a sprocket spoke, more preferably an outer sprocket spoke.

In order to be able to provide the elasticity sufficient for a reduction in stress due to overdetermination of the subassembly connection, the above-mentioned fixing portion of a pinion spoke as a latching counterpart is preferably arranged at a distance from both longitudinal ends of the pinion spoke. The same applies for the same reason for the stop section or / and the counter-stop section of a pinion spoke as a stop counter-formation. Preferably, the fixing portion and / or the stopper portion and / or the counter-abutment portion lie in a middle third of along its, optionally curved, course to be measured longitudinal extent of the pinion spoke, which forms a Verrastungsgegenformation and / or a stop counter-formation. This is especially true when the Verrastungsgegenformation and / or the stop counter-formation is formed by an outer pinion spoke.

Preferably, a radially located between the sprocket area and the hub portion spoke portion has a circumferentially closed encircling coupling ring region on which - when viewed from radially inward to outward - end the inner sprocket spokes and on which the outer sprocket spokes start. This coupling ring region is preferably located in a radial region which extends from one third to two thirds of the radial extent of the entire spoke region occupied by pinion spokes. Preferably, the Coupling ring area in a radial range, which ranges from one third to 7/12 of the radial extent of the spoke area.

In principle, a single pinion spoke can serve as the point of attack of axial fixing projections and counter stop projections, if appropriate also further stop projections, for determining the relative position of the two partial arrangements in all cylinder coordinates. However, a lower mechanical load of the individual pinion spoke by the latching engagement between the first and the second subassembly can be achieved in that the pinion spokes form a plurality of spoke groups, each having at least two pinion spokes. Preferably, each spoke group is associated with a protrusion group described above such that each spoke group cooperates with a protrusion group to form one engagement combination each. The sum of all engagement combinations includes the above-mentioned locking engagement and the two partial arrangements in both circumferential directions for transmitting torque interconnected investment interventions.

In order to be able to form as many engagement combinations in the circumferential direction with the participation of a plurality of sprocket spokes, it is preferably thought that in the circumferential direction directly consecutive sprocket spokes, preferably exactly two immediately consecutive sprocket spokes, form a spokes group. As already explained above, the sprocket spokes are preferably outer sprocket spokes, which is why an even number of outer sprocket spokes are preferably provided.

In principle, it can be thought that the sprocket spokes, in particular the outer sprocket spokes, extend exclusively radially from the hub region or from the coupling ring region to the sprocket region. However, this embodiment is not load-appropriate and therefore not preferred. In view of the torques occurring at the pinion assembly during normal operation around the pinion axis between the sprocket area and hub area sprocket spokes can be formed with a smaller cross-section, if the sprocket spokes in addition to their radial radial component gradient component in the circumferential direction such that a radially further inside spokes portion a radially outwardly located spoke portion of the same sprocket spoke in driving direction of the sprocket arrangement leads. Sprocket spokes are particularly preferably convexly curved when viewed against the driving direction of rotation. This is preferably true for both the radially inner and for the radially outer sprocket spokes.

Another advantage of pinion spokes configured as latching counterforms as described in the previous paragraph is that, if they are not only radial but also circumferential, between the latching formations and the sprocket spokes than the latching counterformations not only forces in the circumferential direction, but also forces in the radial direction can be transmitted.

The latching formations therefore preferably engage in a region of the sprocket spokes having the fixing section, in which they are inclined with respect to the radial direction, preferably between 35 ° and 60 °, particularly preferably between 40 ° and 50 °. Then forces or reaction forces in the radial direction as well as in the circumferential direction can be transmitted between the Verrastungsformationen and the sprocket spokes in approximately equal parts. Said attack of Verrastungsformationen on the sprocket spokes is preferably a contact engagement of a stop surface or a counter-abutment surface on a sprocket spokes laterally limiting edge and a rear engagement of the sprocket spokes by the locking lug of the Axial-Fixiervorsprünge. For the same reason, a pinion spoke forming the stopper portion and / or the counter stopper portion of a stopper counterpart is preferably disposed in a portion of the pinion spoke in which it is inclined with respect to the radial direction, preferably between 35 ° and 60 °, more preferably between 40 ° and 50 °.

Preference is therefore anyway anyway present outer boundary surfaces of the sprocket spokes, in particular the outer sprocket spokes as abutting engagement surfaces with the abutment surfaces of the stop projections and with the counter stop surfaces of the counter stop projections and with the detents and optionally the holding formations of the Axial Fixiervorsprünge. The sum of the acting in different directions investment interventions leads to a secure, because positive locking engagement.

To facilitate the described investment and Formschlusseingriffe that form the Verrastungseingriff between the two sub-assemblies, the pinion spokes at least in the region of Verrastungseingriffs with the Verrastungsformationen when viewed in a respective orthogonal to their respective local spoke longitudinal sectional plane a polyhedral shape, particularly preferably a spoke shape with rectangular cross-section on. In the case of the preferred spoke shape with Rectangular cross-section are two parallel edges of the rectangular cross-section formed by the two end faces of the sprocket spokes and the two remaining parallel edges by connecting the two end faces of the sprocket spokes.

In the from the DE 10 2015 205 736 A1 known pinion arrangement, the first subassembly comprises only the largest pinion of the pinion assembly. However, a higher rigidity of the sprocket arrangement, above all a higher bending stiffness with respect to a bending about a pinion axis orthogonal bending axis, and in particular a higher stiffness of the particularly far radially from the pinion axis projecting first subassembly can be obtained, however, that the first subassembly the largest and The second largest pinion includes, wherein the largest and the second largest pinion are integrally formed with each other. Because of this advantageous effect, the present application, regardless of a latching engagement between the first and the second subassembly also relates to a bicycle rear sprocket assembly, as described in the first paragraph, the first subassembly comprises the largest and integrally formed with this second largest sprocket. The advantageous developments described in the present application also apply to this pinion arrangement and can be realized on this.

Regardless of the other configuration of the sprocket area, spoke area and hub area, the first subassembly is designed such that the hub area is located axially closer to the smallest sprocket than the sprocket area of the largest sprocket in order to increase the strength, in particular flexural strength around a bending axis orthogonal to the pinion rotation axis.

To further stiffen the first subassembly, the first subassembly can have an axial bead encircling the pinion rotational axis in a radial stiffening region between the foot circuits of the largest and the second largest pinion. The axial bead is formed on one side of the first subassembly as a recess and preferably on the opposite side as a bulge. Preferably, the axial bead is formed as an axial recess on the side of the stiffening region pointing to the second largest pinion.

To achieve the most uniform force conditions on the first subassembly, when the bicycle chain with the largest or the second largest pinion is engaged, with low weight of the first subassembly, it is preferably provided that the sprocket spokes radially outward to the sprocket of the largest pinion range, wherein the number of sprocket spokes of the first subassembly in a radial extent range between root circle and tip circle of the second largest pinion is half as large as the number of teeth of the second largest pinion. Because of the outstanding effect of this embodiment with respect to a uniform load during operation of the first subassembly, the present application also relates to a bicycle rear sprocket assembly, as described in the first paragraph, the first subassembly according to regardless of a Verrastungseingriff between the first and the second subassembly trained in this paragraph. This thus formed pinion assembly may have further advantageous features, as described in the present application.

It is particularly preferred that - when looking at the first subassembly in the axial direction - each pinion spoke and every second tooth of the second largest pinion are located at the same circumferential position. Thus, every other tooth, namely each tooth, which is located at a circumferential position between the pinion spokes, accessible in a particularly simple and advantageously axially through the pinion spokes, which facilitates the production of the first subassembly. In addition, when a pinion spoke is located at the same circumferential position as a tooth of the second largest pinion, the power transmission between the second largest and largest pinion takes place immediately where force is transmitted from the bicycle chain to the second largest pinion. Thus, when the second largest sprocket engages the bicycle chain in force transfer engagement, the torque introduced from the bicycle chain into the first subassembly can be easily and safely transmitted to the hub region via the sprocket spokes.

Preferably, at least the second largest pinion, more preferably both the largest and the second largest pinion, the first part of the arrangement at least in a circumferential region in the circumferential direction alternately axially thicker and axially thinner teeth. This simplifies the assignment of inner tab areas and outer tab areas of a bicycle chain interacting with the pinion arrangement to the teeth of at least the second largest pinion, in particular also of the largest pinion, which helps to prevent chain cracks. At least a portion of the teeth located at the same circumferential position as the sprocket spokes of the second largest pinion is preferably formed axially thicker than the teeth immediately adjacent thereto in the circumferential direction. Thus arises between the axially thicker teeth and the existing at the same circumferential position sprocket spokes a relatively small axial gap, which receives the second largest pinion engaged bicycle chain, preferably only the outer plates, with close play. If a pinion spoke and a tooth are arranged at the same circumferential position, then Pinion spoke and tooth overlap when viewed in the axial direction. In this case, that formation of pinion spoke and tooth, which has the larger dimension in the circumferential direction, preferably completely overlaps the respective other formation in the circumferential direction.

The preferred tooth shape of an axially thicker tooth can, irrespective of which pinion it is provided, preferably have the following appearance: the axially facing the next smaller pinion lateral tooth flanks of the axially alternating in a peripheral portion of a pinion axially thinner and the teeth are on a common virtual envelope surface, which is preferably formed rotationally symmetrical with respect to the pinion axis of rotation. Starting from the common virtual envelope surface, the axially thicker teeth approach the next larger pinion axially more than the axially thinner teeth. In this case, the tooth flank of the axially thicker teeth leading in the direction of drive rotation is preferably not stepped, while the opposite trailing tooth flank has an axial step on the side facing the next larger pinion. In other words, starting from a common leading tooth flank, an axially thicker tooth on the side facing the next larger pinion has a smaller dimension in the circumferential direction than on the side facing the next smaller pinion. Considering a circumferential section of an axially thicker tooth along a lateral surface of a cutting cylinder coaxial with the pinion axis of rotation, the axially thicker tooth thus has roughly an L-shaped cross-sectional area. Because of the advantageous effect of the teeth with L-shaped cross-sectional area for guiding a bicycle chain, with the teeth-bearing pinion in positive engagement, the present application, regardless of a Verrastungseingriff between the first and the second subassembly also relates to a pinion assembly, as in the first paragraph of this Application is described, which have teeth in the range from the largest to the second smallest pinion with the described L-shaped circumferential cross-section. Preferably, a plurality of even-numbered pinion gears have such teeth, and more preferably, each even-numbered pinion gear has such teeth. Such a pinion arrangement can be advantageously developed as described in the present application.

Preferably, all of the pinions of the even-toothed-number rear wheel sprocket assembly alternately have an axially thinner and an axially thicker tooth at least over a peripheral region, as described in the preceding paragraph. Only the smallest pinion, which preferably has 10 teeth, has axially thicker teeth, the next largest pinion indicative lateral tooth flank is located on a common virtual envelope surface with the rectified tooth flank of the axially thinner teeth of the peripheral region, wherein the axially thicker teeth starting from the common envelope surface axially further away from the next larger pinion extend away than the axially thinner teeth arranged therebetween. Even at the smallest pinion, the two lateral tooth flanks extend differently far in the circumferential direction, wherein the next largest tooth pinion nearest lateral tooth flank has a larger dimension in the circumferential direction than the opposite lateral tooth flank. Deviating from the other sprockets with an even number of teeth dominates the smallest sprocket pointing to the next larger sprocket lateral tooth flank the pioneering next largest sprocket lateral tooth flank of the same tooth in the circumferential direction both with their vorsteilenden in driving direction longitudinal end and with their trailing longitudinal end. This can be created on the axially outermost smallest pinion in the tooth area space for receiving edge regions of tabs, in particular of outer straps, the bicycle chain. Due to this deviating configuration of the smallest pinion, the skew of the meshing with the smallest pinion bicycle chain can be influenced and unwanted contact of the bicycle chain can be avoided with the next largest pinion. On at least one axially thicker tooth, preferably on a plurality of axially thicker teeth, more preferably on all axially thicker teeth, the transition from the circumferentially longer tooth flank to the circumferentially shorter tooth flank occurs at at least one circumferential longitudinal end of the tooth, preferably at both Circumferential longitudinal ends, stepped, preferably in a single step, to form the chainring of the bicycle chain by the stepped configuration of the tooth flank. Because of the advantageous effect of reducing the effects of skewing of the chain on the smallest sprocket, the present application concerns independently from a latching engagement between the first and second subassemblies also a sprocket arrangement as described in the first paragraph of this application, which has a smallest pinion, which is designed as described in the present paragraph. At this pinion arrangement, one or more further developments can be realized, as described in this application.

In contrast to the above-mentioned roughly L-shaped cross-section, the axially thicker teeth on the smallest sprocket in the abovementioned circumferential sectional view have a roughly T-shaped cross section.

Preferably, the second subassembly has more sprockets than the first subassembly, more preferably at least twice as many, or at least three times or even four times as many pinions as the first subassembly. Thus, the second subassembly can be a series of between 6 and 12 axially integrally formed pinions have formed integrally with each other. A total number of pinions of the pinion assembly of about 7 or 8th Pinion is applicable for e-bikes and pedelecs, in which due to the motor support of the cyclist, a larger number of teeth difference between axially immediately adjacent pinions can be accepted.

Preferably, the second subassembly has the third largest sprocket of the sprocket assembly. This is more preferably the largest pinion of the second subassembly.

Likewise, the second subassembly may have the smallest sprocket. Particularly preferably, the pinion arrangement in addition to the first and the second sub-assembly on no further sub-assembly or no further single pinion, which greatly facilitates the assembly of the pinion assembly because of the small number of components. However, it should not be ruled out that, in addition to the first and second subassembly, a further subassembly or a single pinion is provided on the sprocket assembly.

To save weight, the individual integrally formed pinion of the second subassembly are interconnected by webs. Preferably, the two webs connecting axially directly adjacent pinions do not extend radially beyond the pinion rotation axis beyond the toothed rim of the smaller of the two pinions. An advantageous force transmission between axially immediately adjacent integrally formed with each other pinions of the second subassembly can be achieved that for at least one pairing, preferably for several pairings, particularly preferably for all pairings of a pinion and its adjacent next smaller pinion of the second subassembly that the pinion is connected to the next smaller pinion by integrally formed with two pinions webs. Preferably, to facilitate cleaning of the second subassembly and to reduce its weight, the number of lands connecting a larger sprocket to an axially immediately adjacent smaller sprocket of one pair of scribe pairs is less than the number of teeth of the smaller sprocket. It is particularly preferred then when the next smaller pinion has a straight number of teeth, the number of webs connecting the two pinions is exactly half the size of the straight number of teeth of the next smaller pinion. The above applies to the half number of sprocket spokes in relation to the number of teeth of the second largest sprocket of the first subassembly. The number of webs may also be less than half the number of teeth of the smaller pinion of the pairing. Preferably, the number of lands and the number of teeth of the smaller pinion of a pair of axially adjacent adjacent and connected by the webs pinions on a common integer divider. This makes it possible to provide a web always in the same circumferential position on the smaller pinion of the pairing in a stiffness-increasing manner as a tooth. Preferably, said condition for each pairing consists of two immediately axially adjacent pinions of the second subassembly, preferably even number of teeth, of the smaller of the two pinions. If a web and a tooth are arranged at the same circumferential position, the web and the tooth overlap when viewed in the axial direction. In this case, that formation of web and tooth, which has the larger dimension in the circumferential direction, preferably completely overlaps the respective other formation in the circumferential direction.

Likewise for weight saving, the first subassembly with the largest sprocket, and preferably also with the second largest sprocket formed integrally with the largest sprocket, is made of a material of lower density, for example of an aluminum alloy. The second subassembly, which has more than two, preferably about ten pinions integrally formed, is preferably made of a material of greater density and preferably larger elastic modulus, for example made of steel for reasons of strength.

With reference to the advantages already mentioned above in relation to the first subassembly, these advantages can also be achieved on the second subassembly if - when considering the second subassembly in the axial direction - for at least one pairing, preferably for each pairing, of a pinion and of the same adjacent next smaller pinion, the latter preferably with even number of teeth, the second sub-assembly is that each web and a tooth, preferably every other tooth, the next smaller pinion are located at the same circumferential position. This improves the power transmission between the integrally formed pinions and facilitates the accessibility of at least every other tooth of an even smaller pinion during manufacture and optionally during assembly. Because of the superior power transmission and accessibility of teeth of a pinion, preferably even number of teeth in an integrally formed, multiple pinion having second subassembly, the present application, regardless of a latching engagement between the first and the second subassembly also relates to a bicycle rear sprocket assembly, such as it is described in the first paragraph, the second sub-arrangement of which is in accordance with this paragraph and / or one of the two preceding paragraphs. This so formed Pinion assembly may have further advantageous features as described in the present application.

An improved chain guide and a reduced risk of chain cracks can, as explained above for the first subassembly, also be achieved on the second subassembly, if at least one pair of the teeth located at the same circumferential position as webs is the next smaller one Ritzels are axially thicker than the teeth immediately adjacent thereto in the circumferential direction. However, it should not be ruled out that a web is also arranged at the circumferential position of at least one axially thinner tooth. This may be advantageous, for example, if the smaller pinion in the peripheral region of one of its thinner teeth is weakened by a lateral indentation or recess, for example due to a chain-climbing aid designed as a recess in the pinion end face, in at least one of its end faces. Then, the web can reinforce the peripheral area of the thinner tooth and / or stiffen. Therefore, the webs of a scribe pair need not necessarily be arranged equidistantly in the circumferential direction, although this is preferred.

Then, when the number of teeth of the smaller sprocket of a pair is odd, the number of lands may be equal to the number of teeth of the smaller sprocket. Again, however, it should be understood that the number of lands may be less than the number of teeth, although again it is preferred that the number of lands on the one hand and the number of teeth on the other have a common integer divisor.

Particularly preferably, webs are arranged only at those circumferential positions at which there is also a tooth of the smaller pinion of the pairing.

The shape of the axially thicker and thinner teeth and the second subassembly has already been explained above.

For most effective force and torque transmission through the webs of the second subassembly, the webs are arranged not only radially extending between the axially immediately adjacent pinions connected by them. Preferably, the webs also have a leveling component in the circumferential direction, and particularly preferably so that their radially inner end trailing their radially outer end in the drive direction of rotation.

Preferably, the sprocket assembly has eight to fourteen pinions, preferably 12 to 14 Pinion, wherein the smallest pinion not more than twelve, preferably not more than ten, preferably exactly ten teeth and / or that the largest pinion not less than 50 , preferably not less than 52 , more preferably exactly 52 Has teeth. To maximize the use of the above described advantageous coordinated spatial arrangement of pinion spokes and teeth of the second largest pinion and of webs and teeth on sprockets of the second subassembly, the sprocket assembly preferably not more than two, more preferably not more than one pinion with odd number of teeth on. According to a preferred embodiment, the sprocket arrangement has the following numbers of teeth from the smallest to the largest of two sprockets: 10 . 12 . 14 . 16 . 18 . 21 . 24 . 28 . 32 . 38 . 44 . 52 ,

As already explained above, it is preferred that a plurality of teeth with an even number of teeth, preferably on all sprockets with an even number of teeth, each at least on one peripheral portion, more preferably on a plurality of peripheral portions, most preferably along the entire circumference in the circumferential direction alternately an axially thicker tooth and an axially thinner tooth arranged consecutively.

Typically, the sprocket assembly discussed herein is used with a structurally conventional bicycle chain which has approximately equidistant rollers along its chain longitudinal direction that are alternately interconnected in the chain longitudinal direction by a pair of inner straps and a pair of outer straps. The axially thicker teeth preferably have a thickness matched to the shape of the cooperating bicycle chain such that their axial dimension is greater than the inside width between the inner straps of an inner strap pair, so that the axially thicker teeth are fully intended only in a tooth entry space of the bicycle chain limited by outer straps can dive. Thus, when the bicycle chain is engaged with a straight-toothed pinion gear, it is uniquely positioned in the chain longitudinal direction with respect to the pinion. This also reduces the risk of chain breaks. Due to the above-mentioned preferred at least circumferentially realized alternating arrangement of axially thicker and thinner areas is on a plurality of sprockets with even number of teeth, preferably on all sprockets with even number of teeth except the two smallest sprockets, particularly preferably on all sprockets with even number of teeth, in Trap of a positive engagement with the bicycle chain along the form-locking region a web or / and a sprocket spoke, in particular outer sprocket spoke, always only one outer link of the chain opposite.

The clear width between the outer straps of an outer strap pairing of the bicycle chain is thereby larger than the clear width between the inner straps of an inner strap pairing.

The present application therefore also relates to a bicycle drive assembly comprising the above bicycle chain and further comprising a pinion assembly as described and further developed in the present application.

Said bicycle drive assembly preferably has exactly one sprocket on the crank of a bicycle driving assembly bearing bicycle, so that changes in a transmission ratio of the crank to the rear hub take place exclusively on the rear sprocket assembly.

• 1 eine schematische Seitenansicht eines Fahrrads mit einer Fahrrad-Antriebsbaugruppe gemäß der vorliegenden Anmeldung,
• 2 eine perspektivische Ansicht einer erfindungsgemäßen Fahrrad-Hinterrad-Ritzelanordnung der Antriebsbaugruppe des Fahrrads von 1 bei Betrachtung von schräg außen,
• 3 eine Seitenansicht der Ritzelanordnung von 2 bei Betrachtung orthogonal zur Ritzeldrehachse,
• 4 eine Längsschnittansicht einer Radialhälfte der Ritzelanordnung der 2 und 3 entlang einer die Ritzeldrehachse enthaltenden Schnittebene,
• 5 eine axiale Ansicht der Ritzelanordnung der 2 bis 4 entlang der Ritzeldrehachse von außen, also in Richtung zu einer zur Ritzeldrehachse orthogonalen Längsmittelebene des Fahrrads von 1 hin,
• 6 eine axiale Ansicht der Ritzelanordnung der 2 bis 5 in entgegengesetzter Blickrichtung, verglichen mit 5,
• 7 eine perspektivische Ansicht der ersten Teilanordnung der Ritzelanordnung der 2 bis 6 von schräg außen,
• 8 eine Schnittansicht der ersten Teilanordnung von 7 entlang einer die Ritzeldrehachse RA enthaltenden Schnittebene,
• 9 eine axiale Ansicht der ersten Teilanordnung der 7 und 8 von außen,
• 10 eine axiale Ansicht der ersten Teilanordnung der 7 bis 9 von innen,
• 11 eine perspektivische Ansicht der zweiten Teilanordnung der Ritzelanordnung der 2 bis 6 von schräg außen,
• 12 eine Seitenansicht der zweiten Teilanordnung der Ritzelanordnung der 2 bis 6 mit Blickrichtung orthogonal zur Ritzeldrehachse,
• 13 eine axiale Ansicht der zweiten Teilanordnung der Ritzelanordnung der 2 bis 6 von innen,
• 14 eine perspektivische Ansicht der zweiten Teilanordnung von schräg innen,
• 15 einen vergrößerten Ausschnitt eines Bereichs der beiden größten Ritzel der zweiten Teilanordnung von 14,
• 16 eine perspektivische Ansicht der Ritzelanordnung mit beiden Teilanordnungen von schräg hinten,
• 17 eine axiale Ansicht der vom kleinsten Ritzel der Ritzelanordnung der 2 bis 6 weg weisenden Stirnseite eines beliebigen Ritzels der Ritzelanordnung, mit Ausnahme des kleinsten Ritzels, und
• 18 eine perspektivische Ansicht des kleinsten Ritzels der Ritzelanordnung von schräg außen.

The present invention will be explained in more detail with reference to the accompanying drawings. It shows:

• 1 1 is a schematic side view of a bicycle with a bicycle drive assembly according to the present application;
• 2 a perspective view of a bicycle rear sprocket assembly according to the invention of the drive assembly of the bicycle of 1 when viewed from an angle,
• 3 a side view of the pinion assembly of 2 when viewed orthogonal to the pinion axis,
• 4 a longitudinal sectional view of a radial half of the pinion assembly of 2 and 3 along a cutting plane containing the pinion axis,
• 5 an axial view of the pinion assembly of 2 to 4 along the pinion axis of rotation from the outside, that is to say in the direction of a longitudinal center plane of the bicycle orthogonal to the pinion rotation axis 1 out
• 6 an axial view of the pinion assembly of 2 to 5 in the opposite direction compared to 5 .
• 7 a perspective view of the first subassembly of the pinion assembly of 2 to 6 from diagonally outside,
• 8th a sectional view of the first subassembly of 7 along a cutting plane containing the pinion rotation axis RA,
• 9 an axial view of the first subassembly of 7 and 8th from the outside,
• 10 an axial view of the first subassembly of 7 to 9 from the inside,
• 11 a perspective view of the second subassembly of the pinion assembly of 2 to 6 from diagonally outside,
• 12 a side view of the second subassembly of the pinion assembly of 2 to 6 with view orthogonal to the pinion axis,
• 13 an axial view of the second subassembly of the pinion assembly of 2 to 6 from the inside,
• 14 a perspective view of the second subassembly of obliquely inside,
• 15 an enlarged section of a portion of the two largest pinions of the second subassembly of 14 .
• 16 a perspective view of the pinion assembly with two sub-assemblies obliquely from behind,
• 17 an axial view of the smallest pinion of the pinion assembly of 2 to 6 wegweisenden end face of any pinion of the pinion arrangement, with the exception of the smallest pinion, and
• 18 a perspective view of the smallest pinion of the pinion assembly from obliquely outside.

In 1 is a schematic side view of a bicycle 10 with a bicycle drive assembly according to the invention 12 shown. The bike 10 has a frame 14 with a sprung steerable front wheel 16 and a sprung rear wheel 18 on. The front wheel 16 is by means of a handlebar 20 steerable. On a saddle 22 of the bicycle 10 a cyclist can sit during his ride. The forward direction of travel on a level surface U standing up shown bicycle 10 is with the arrow V characterized.

The bicycle drive assembly 12 In the illustrated preferred embodiment, it includes a single front sprocket 24 , which directly with cranks 26 Torque transmitting coupled, and includes one with the single front chainring 24 in a known manner via a bicycle chain 28 Power transmitting connected rear sprocket assembly 30 , The rear wheel sprocket assembly 30 is torque transmitting with the rear wheel 18 coupled, so one over the cranks 26 in the front chainring 24 initiated torque over the bicycle chain 28 and the rear wheel sprocket assembly 30 on the rear wheel 18 is transmitted.

By means of a chain circuit not described in detail 32 can the bicycle chain 28 in force transmitting engagement with one of, for example, twelve pinions R1 to R12 the rear wheel sprocket assembly 30 to be brought. That's the way the bike works 10 driving driver in a conventional manner Speed and torque transmission ratio of the front chainring 24 to the rear wheel 18 choose.

In the 2 to 6 is the rear wheel sprocket assembly 30 shown in detail in different views. 2 shows a perspective view of the pinion assembly 30 obliquely from the front or obliquely outside, that is from an observer position, which is the smallest pinion R12 closer than the largest pinion R1 the pinion arrangement 30 , 3 shows a side view of the pinion assembly 30 with view orthogonal to the pinion axis RA , 4 shows a longitudinal sectional view of a radial half of the pinion assembly 30 along a pinion axis of rotation RA containing cutting plane. 5 shows the pinion assembly 30 when viewed along the pinion axis of rotation RA from the outside, so one to the pinion axis RA orthogonal longitudinal median plane of the bicycle 10 from 1 out. 6 shows the pinion assembly 30 when viewed in the axial direction, but in the opposite direction as 5 , ie from the inside or from the longitudinal center plane of the bicycle 10 path.

The pinion arrangement 30 includes a first subassembly 32 , which is the biggest sprocket R1 with preferably 52 Teeth and the second largest sprocket R2 with preferably 44 Having teeth integrally formed. The integrally formed first subassembly 32 is preferably formed of an aluminum alloy around the first subassembly 32 form with the lowest possible weight.

The pinion arrangement 30 further has one with the first subassembly 32 firmly connected second subassembly 34 on, on which all other sprockets R3 to R12 the pinion arrangement 30 are integrally formed. The pinion R3 is the third largest sprocket, the pinion R12 is the twelfth largest or smallest pinion of the pinion assembly 30 , The one-piece second subassembly 34 is made of steel for reasons of maximum strength. The third largest sprocket R3 the pinion arrangement 30 which is the largest sprocket of the second subassembly 34 is, preferably, points 38 Teeth on. The smallest sprocket R12 preferably 10 Pinion up.

The first subassembly 32 and the second subassembly 34 are interconnected by locking and secured against axial removal from each other, as will be explained in detail below. The between the first and the second subassembly 32 or. 34 formed connection connects the sub-assemblies 32 and 34 for common movement with each other in both opposite circumferential directions about the pinion axis of rotation RA as well as in both opposite axial directions along the pinion axis of rotation RA ,

The driving direction of rotation of the pinion arrangement 30 into which the pinion arrangement 30 by pedaling the cranks 26 is turned to the bike 10 in forward direction V is to move in the figures by the reference numeral DR designated. In the axial view from the outside according to 5 runs the driving direction DR clockwise, in the axial view from the inside according to 6 , the drive direction of rotation runs DR accordingly counterclockwise.

As best in the views of 4 and 6 can be seen, the first subassembly has 32 a radially inner hub region 32a which is used to transmit torque from the sprocket assembly 30 or from the first subassembly 32 on a driver and thus on a hub of the rear wheel 18 is trained. For this purpose, the hub area 32a radially inside, for example, a spline.

In addition, the first subassembly has 32 , a tooth 36a and 36b the largest pinion R1 having radially outer sprocket area 32b on. How to be especially in 4 detects, is the hub area 32a opposite the sprocket area 32b axially to the smallest sprocket R12 arranged offset, which is the first subassembly 32 a bending stiffness increased with respect to a bending around a pinion axis of rotation relative to a planar design RA gives orthogonal bending axis.

The teeth 36a the largest pinion R1 are at least in some peripheral portions of the pinion R1 thicker in the axial direction than the adjacent teeth in the circumferential direction 36b , The axial thickness of the thicker teeth 36a is chosen such that it is greater than the clear width between an inner strap pairing of the chain 28 , At the bicycle chain 28 are equidistant roles in a conventional manner along the chain longitudinal direction by alternately alternating outer strap pairings 28a and inner strap pairings 28b connected to each other, wherein the clear width between an inner strap pairing 28b smaller than between an outer strap pairing 28a , In 1 is the clear width of outer strap pairings 28a as well as inner strap pairings 28b parallel to the pinion axis of rotation RA to eat. The roller axes of the through the inner strap pairings 28b and outer strap pairings 28a with each other equidistantly connected roles of the bicycle chain 28 run in 1 also parallel to the pinion axis RA , The pinion axis RA is in 1 orthogonal to the plane of the 1 ,

Radial between the hub area 32a and the sprocket area 32b is a spoke area 32c located, which the hub area 32a with the sprocket area 32b combines.

As well in the axial interior view of the sprocket assembly 30 from 6 but even better in the axial views of the first subassembly 32 the 9 and 10 can be seen includes the spoke area 32c radially inner sprocket spokes 38 and radially outer sprocket spokes 40 , The radially inner sprocket spokes 38 range from the hub area 32a to a closed circumferential coupling ring area 42 , The radially outer sprocket spokes extend from the coupling ring area 42 to the tooth area 32b , The inner and outer sprocket spokes 38 or. 40 preferably do not overlap in the radial direction. The number of outer sprocket spokes 40 is greater than the number of inner sprocket spokes 38 , for the sake of a homogeneous force distribution in the circumferential direction about the pinion rotation axis RA, preferably by the factor 2 ,

On the illustrated embodiment of the first subassembly 32 are in a particularly advantageous manner, half as many outer sprocket spokes 40 provided as axially adjacent to the outer sprocket spokes 40 located teeth of the second largest pinion R2 ,

For dimensionally stable transmission of torque from the sprocket area 32b to the hub area 32a with the smallest possible spoke cross-section are both the inner sprocket spokes 38 as well as the outer sprocket spokes 40 to its stiffening in such a way with a course component in the circumferential direction about the pinion axis of rotation RA formed such that the respective radially inner end of a pinion spoke 38 or. 40 in driving direction DR the radially outer end of the same sprocket spoke 38 or. 40 is ahead. In addition, the sprocket spokes 38 and 40 one to the pinion axis of rotation RA parallel axis of curvature formed curved so that the pinion spokes 38 and 40 when viewed in driving direction DR are curved concavely and when viewed against the driving direction DR are curved convexly.

The coupling ring area 42 lies with respect to the radial extent 44 of the spoke area 32c in a region between the radially inner third of the extension 44 and half of them (see 10 ).

How very good in 10 It can be seen, every second tooth is the second largest pinion R2 - these teeth are with 46a designated - at the same circumferential position as an outer pinion spoke 40 , As a result, those are between the teeth 46a located teeth 46b axially through the outer sprocket spokes 40 easily accessible and can be machined in a simple manner by a milling tool with high precision.

The in terms of their circumferential position with the outer sprocket spokes 40 matching teeth 46a are at least in some peripheral sections of the second largest pinion R2 axially thicker teeth than the circumferentially adjacent teeth 46b , Due to this axially thicker formation of at least a portion of the teeth 46a can the one-piece connection of the second largest pinion R2 to the biggest sprocket R1 very easy and stable.

The cutting plane of the 4 and 8th does not pass through the circumferential position at which an outer pinion spoke 40 and an axially thicker tooth 46a the second largest pinion R2 axially opposite. Nevertheless, the show 4 and 8th in that, by means of this axial comparison, an axial gap 48 between an outer sprocket spoke 40 and a tooth 46a of the pinion R2 has a relatively small axial dimension, whereby the bicycle chain 28 then, when in positive engagement with the pinion R2 is, can be recorded with little axial play.

As in particular the 4 and 8th can be removed, the sprocket area 32b the largest pinion R1 to stiffen this pinion R1 a circular groove running around the pinion axis RA circular axial 50 on which of the second sub-assembly 34 pointing side into the biggest sprocket R1 was introduced. Therefore, the largest pinion has R1 on his second largest sprocket R2 indicative side of a depression 50a on. The axial bead 50 is on the opposite, from the second largest sprocket R2 pointing away side as a bulge 50b educated. The axial bead 50 is located radially in a stiffening area 51 , which is between the foot circles of the first pinion R1 and the second pinion R2 , preferably even between the tip circle of the second pinion R2 and the root circle of the first pinion R1 is located.

The 11 to 13 show the second subassembly 34 in isolation. The 11 shows the second subassembly 34 while in perspective view obliquely outside. The 12 shows the second subassembly 34 in side view orthogonal to the pinion axis of rotation RA , The 13 shows the second subassembly 34 in axial view from the inside.

The 13 shows the integral formation of the second subassembly 34 , Every pinion R3 at least R9 has a pinion gear carrying the pinion teeth and thereof radially inwardly projecting webs, which a pinion of the second subassembly 34 connect integrally with the axially adjacent next smaller pinion.

For the sake of clarity, only the ring gear of the largest pinion is an example R3 the second subassembly 34 with the reference numerals 52 and the one radially inward to the next smaller pinion R4 protruding ridges with reference numerals 54 designated. The bridges 54 protrude radially inward not on the sprocket of each next smaller pinion, here pinion R4 , Beyond, with which they are formed directly in one piece.

In the present embodiment, the number of teeth of all the pinions except the pinion R7 , the 21 is, straight. For those pairings of axially immediately adjacent pinions of the second subassembly 34 whose smaller pinion has a straight number of teeth, every other tooth of the smaller pinion of the pairing is at the same circumferential position as a web. This is in 13 for the Ritzelpaarung R3 / R4 vividly. Here is the number of bars 54 that's the bigger sprocket, here R3 , with the smaller sprocket, here R4 , connects, half the size of the number of teeth of the smaller pinion. Thus, each second tooth of the smaller pinion is also axially from both sides of the second subassembly 34 accessible.

A majority of the teeth 56a of the pinion R4 , which are at the same circumferential position as the pinion R3 and the pinion R4 integrally interconnecting webs 54 are axially thicker than the teeth lying in the circumferential direction between these teeth 56b , Again, by the axially thicker training with respect to their circumferential position with the webs 54 coincident teeth 56a the integral connection of the pinions R3 and R4 stable with each other and an axial gap 58 between a footbridge 54 and an axially adjacent tooth 56a be carried out with relatively small gap width. The axial gap 58 can then the bicycle chain 28 axially absorb with little play, if this in positive engagement with the pinion R4 stands.

For the pairing of the pinions R6 and R7 applies because of the odd number of teeth of the pinion R7 not the above. There leads at each circumferential position of a tooth of the pinion R7 a bridge from the pinion R6 to the next smaller pinion R7 and connects these two together in one piece. Because of the larger number of webs, the individual webs can be made shorter in the circumferential direction than the webs of those Ritzelpaarungen whose smaller pinion has a straight number of teeth.

As well as in 13 can be seen, are the webs (see, for example, webs 54 ) is tilted between the axially immediately adjacent pinions in addition to their radial extent in the circumferential direction, and opposite to the direction of inclination of the pinion spokes 38 and 40 the first sub-arrangement. The axially immediately adjacent pinion of the second subassembly 34 connecting webs are inclined in the circumferential direction such that their radially inner end the radially outer end in driving direction DR lags. Accordingly, the radially outer end leads the radially inner end in the drive direction of rotation DR ahead. This is load-bearing, since the pinions R3 to R12 the second subassembly 34 on her from the bicycle chain 28 directly transmitted torque to the first subassembly 32 transfer it to the hub area 32a and finally transfers to the rear hub.

As the 11 to 13 show, stand from the sprocket 52 the largest pinion R3 the second subassembly 34 three structurally different types of axial projections 60a . 60b and 60c to the first sub-arrangement 32 in from. In each case a combination of an axial projection 60a . 60b and 60c forms a projection group 62 standing at a section 64 the outer sprocket spokes 40 attacks. The section 64 , which is also fixing portion as abutment portion and counter-abutment portion, runs in the circumferential direction completely around the pinion rotation axis RA around. Because of its property both as a fixing section as well as a stopper portion and as a counter stop section is the section 64 hereinafter referred to as "attacking section". Only for reasons of clarity in the figures are only on some outer sprocket spokes 40 reference numeral 64 for identifying the attacking section of the projection groups 62 at the first subassembly 32 arranged.

The lead groups 62 are circumferentially about the pinion axis of rotation RA over the entire circumference of the sprocket 52 distributed so that the sprocket 52 and with this the second subassembly 54 over the entire circumference of the sprocket 52 evenly with the first subassembly 32 are connected.

In 6 can be seen, as the axial projections 60a . 60b and 60c with the outer sprocket spokes 40 the first sub-arrangement 32 interact to form the first and second subassemblies 32 or. 34 rotatably and axially immovable to connect with each other. The axial projections 60a . 60b and 60c Repeat periodically in the circumferential direction.

The latching connection between in subassemblies 32 and 34 is described below on the basis of 14 to 16 explained. The 14 shows a perspective view of the second subassembly 34 from diagonally inside. 15 shows an enlarged section of a range of the two largest sprockets R3 and R4 the second subassembly 34 from 14 , 16 shows a perspective view of the pinion assembly 30 with both partial arrangements 32 and 34 from diagonally inside.

The axial projection 60a is axially shorter than the other two types of axial projections 60b and 60c , The axial projection 60a is a counter stop projection, which with its counter stop surface 66 on a lateral boundary surface 68 an outer sprocket spoke 40 in the attack section 64 (in its function as a counter-stop section) is applied.

In the attack section 64 is the lateral boundary surface 68 at which counter stop surface 66 rests, with respect to a pinion axis of rotation RA containing reference plane inclined by about 45 °, so that by the investment engagement between the counter stop surface 66 and the lateral boundary surface 68 forces acting in the circumferential direction as well as in the radial direction between the component sections involved 40 and 60a can be transmitted.

The axial projection 60a also has an inclined surface 70 which is inclined so that a migratory on her, axially to the root area 70a of the axial projection 60a on the sprocket 52 approaching point in both the radial direction and in the circumferential direction of the counter stop surface 66 approaches.

The axial projection 60b is a stopper projection, which in the opposite direction as the counter stop surface 66 a counter-stop projection 60a the same projection group 62 pointing stop surface 74 exclusively an investment engagement with a lateral boundary surface 76 an outer sprocket spoke 40 in the attack section 64 (now in its function as an abutment section) is used. The boundary surface 76 is the boundary surface 68 opposed. Also the boundary surface 76 is therefore inclined by 45 ° with respect to the reference plane mentioned above. Thus, even in the abutting engagement between the stop surface 74 and the boundary surface 76 both force in the radial direction and force in the circumferential direction between the axial projection 60b and the outer sprocket spoke 40 be transmitted.

The two surfaces: stop surface 74 and counter-attack surface 66 limit a recording room 78 in which an outer sprocket spoke 40 is recorded. The distance of the counter stop surface 66 and the stop surface 74 the same projection group 62 corresponds essentially to the thickness of the outer sprocket spoke 40 so that they are substantially free of play in the receiving space in a direction orthogonal to the pinion rotation axis 78 can be arranged. The inclined surface 70 facilitates the insertion of the associated outer sprocket spoke 40 in the recording room 78 ,

The entirety of the counter-stop projections 60a and the stopper protrusions 60b the second subassembly 34 thus puts the two sub-orders 32 and 34 relative to each other in the radial direction as well as in the circumferential direction fixed.

The axial projection 60c is an axial fixing projection. He has a catch 80 on which of the axial projection 60c protrudes both in the circumferential direction as well as in the radial direction relative to the pinion rotation axis RA.

Between the catch 80 and the root area 70c , more precisely one to the catch nose 80 indicative outer surface 71 of the root area 70c from which, starting from the axial projection 60c from the sprocket 52 axially protrudes, is a holding space 82 formed, whose by the catch nose 80 and the root area 70c defined dimension in the axial direction substantially the axial thickness of an outer pinion spoke 40 in the area 64 matches, so the attack section 64 (now in its function as a fixing section) of the outer pinion spoke 40 as axially as possible without play in the holding space 82 can be recorded.

The totality of all axial projections 60c sets the two sub-orders 32 and 34 fixed relative to each other axially immovable to each other. The inclined surfaces 66 the counter stop projections 60a also facilitate insertion of the attack section 64 an outer sprocket spoke 40 in the respective holding spaces 82 the Axial Fixiervorsprünge 60c ,

The axial projection 60c is in addition also stop projection, because he has a stop surface 84 on which between the latch 82 and the root area 70c or its outer surface 71 , a stop tab 60c is located. This stop surface 84 is for attachment to a lateral boundary surface 86 an outer sprocket spoke 40 educated. The catch 82 is on the other hand to the system engagement on a frontal boundary surface 86 an outer sprocket spoke 40 educated.

The axial projections 60c thus form Verrastungsformationen the second subassembly 34 , which with Verrastungsgegenformen in the form of the outer sprocket spokes 40 in the attack section 64 cooperate to form a practically insoluble locking engagement.

One and the same projection group 62 acts with one of two circumferentially immediately adjacent outer sprocket spokes 40 formed spoke group 41 put together on a single sprocket spoke 40 to reduce or limit the force exerted.

In the area of the attack section 64 sufficiently elastic deformability for the actually mechanically overdetermined connection of the first and second subassembly 32 or. 43 to be able to provide, lies the attack section 64 on each outer sprocket spoke 40 at a distance from its two longitudinal ends in one the longitudinal center of the pinion spoke 40 containing central portion of the outer sprocket spoke 40 , The length of this central region is not more than a third, preferably not more than a quarter of the total length of the pinion spoke 40 ,

The axially thicker teeth of the pinions R1 to R6 and R8 to R11 of which previously exemplified the teeth 36a . 46a and 56a are mentioned below in terms of their shape on the basis of 17 explained in more detail.

The 17 shows the above-mentioned longitudinal center plane of the bicycle 10 facing end face of any pinion R1 to R6 and R8 to R11 , Provided that in 17 partially shown pinion not the largest pinion R1 is, you look at the next to each larger pinion facing end side.

The formed on these sprockets axially thicker tooth with the reference numerals 36a . 46a or 56a has on the basis of a common leading in driving direction DR leading tooth flank 88 initially at a constant radial coordinate in the circumferential direction in about a constant axial thickness. To the viewer the 17 However, lateral side tooth flank is shorter in the circumferential direction than that of the observer 17 groundbreaking, opposite lateral tooth flank. In the area of the trailing tooth trailing in DR direction DR 90 is on the viewer facing lateral tooth flank an axial jump 92 formed, in which the axial thickness of the tooth shown decreases suddenly. The axial jump 92 runs from the viewer of the 17 path.

Thus, the dimension in the circumferential direction of the axially thicker tooth 36a . 46a or 56a starting from the common leading tooth flank 88 on the viewer of 17 facing side shorter than on the opposite side facing away. The axially thicker tooth thus has a roughly L-shaped circumferential cross-section.

The axial jump 92 may be part of a recess, which is the spatial inclusion of an outer flap of the bicycle chain 28 serves.

In 18 is the smallest sprocket R12 the pinion arrangement 30 seen in perspective from obliquely outside. Because the chain 28 then, when engaged with the smallest sprocket R12 is a particularly strong skew with respect to the above to the pinion axis of rotation RA orthogonal longitudinal median plane of the bicycle 10 has, have the smallest pinion R12 trained axially thicker teeth 96a a different shape than the other sprockets (with the exception of the pinion R7 ) formed axially thicker teeth.

For one, it is the smallest sprocket R12 the dimension in the circumferential direction of the next largest pinion or the largest pinion R1 indicative lateral tooth flank larger than the dimension in the circumferential direction of the largest pinion R1 groundbreaking lateral tooth flank. The latter is the viewer of 18 facing lateral tooth flank.

On the other hand, the observer of the 18 opposite lateral tooth flank which the viewer of 18 facing lateral tooth flank in the circumferential direction on both sides. The axially thicker tooth 96 the smallest sprocket R12 thus has a roughly T-shaped circumferential cross-section.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102015205736 A1 [0003, 0004, 0005, 0047]

Claims (36)

A bicycle rear sprocket assembly (30) rotatable about a common pinion rotational axis (RA) defining an axial direction and orthogonal thereto radial directions, comprising a plurality of coaxially arranged with respect to said pinion rotational axis (RA) for common rotation about said pinion rotational axis (Fig. RA) interconnected pinions (R1-R12) of different size and number of teeth, the pinion assembly (30) comprising a first subassembly (32) comprising the largest sprocket (R1) and a second subassembly (34) comprising a plurality of integral with each other formed pinion (R3-R12), characterized in that a subassembly (34) of first and second subassembly (32, 34) has a plurality of elastically deformable Verrastungsformationen (60c), which with a plurality of Verrastungsgegenformationen (40) of each other sub-assembly (32) are in latching engagement, wherein the latching engagement the two sub-assemblies ( 32, 34) secures against removal from each other in the axial direction. Bicycle rear sprocket assembly (30) according to Claim 1 , characterized in that the Verrastungsformationen (60c) or / and the Verrastungsgegenformationen (40) integral with the respective sub-assembly (32, 34) are formed. Bicycle rear sprocket assembly (30) according to Claim 1 or 2 characterized in that the latching formations (60c) have axial fixing protrusions (60c) projecting axially from the subassembly (34) having them, which are spaced axially from a root region (70c) from which they have their subassembly (34) ), in the circumferential direction about the pinion axis (RA) and / or in the radial direction of the respective axial projection (60c) protruding locking lug (80). Bicycle rear sprocket assembly (30) according to Claim 3 characterized in that at least one axial fixing projection (60c), preferably all axial fixing projections (60c), axially hold a fixing portion (64) of the latching counterforms (40) in a retaining space (84), which retention space (84 ) axially in a first direction by the latching lug (80) and in one of the first opposite second direction by an axially spaced therefrom, parallel to the latching lug (80) extending holding formation (71), preferably the root portion (70c) limited is. Bicycle rear sprocket assembly (30) according to Claim 3 or 4 characterized in that the axial fixing projections (60c) are deformable in a direction orthogonal to the pinion rotation axis (RA), and are preferably rigid in the axial direction. Bicycle rear sprocket assembly (30) according to one of the preceding claims, characterized in that it comprises axial projections (60b, 60c) as abutment projections (60b, 60c) with a stop surface (74, 82) which is orthogonal in a direction of action with a progressive component to the pinion rotation axis (RA), preferably orthogonal to the pinion axis of rotation (RA), and on which a respective stop portion (76, 84) of a stop mating formation (40), preferably a Verrastungsgegenformation (40), is applied. Bicycle rear sprocket assembly (30) according to Claim 6 characterized in that it comprises axial projections (60a) as counter-abutment projections (60a) with a counter-abutment surface (66) pointing in a counteracting direction with a trajectory component orthogonal to the pinion axis of rotation (RA), preferably orthogonal to the pinion axis of rotation (RA) a counter-abutment portion (68) of a stop mating formation (40), in particular a Verrastungsgegenformation (40) is applied, wherein the radial gradient components and / or the course components in the circumferential direction of effective direction and counter-acting direction of abutting one and the same abutment mating stop surfaces and counter stop faces in opposite directions. Bicycle rear sprocket assembly (30) according to Claim 7 characterized in that at least a portion of the counter-abutment projections (60a), preferably all counter-abutment projections (60a), have an inclined surface (70) at their cantilevered longitudinal end, the counter-abutment surface (66) axially between the inclined surface (70) and a root portion (70a) from which the counter-abutment projections (60a) project from the subassembly (34) having them, and wherein the inclined surface (70) is inclined so as to project axially toward the root portion (70a) migrating point approaches in the radial direction and / or in the circumferential direction of the counter-abutment surface (66). Bicycle rear sprocket assembly (30) according to any one of Claims 3 to 8th , including the Claim 6 , characterized in that at least part of the axial fixing projections (60c), preferably all the axial fixing projections (60c), are also stop projections. Bicycle rear sprocket assembly (30) according to any one of Claims 3 to 9 , including the Claims 3 . 6 and 7 , characterized in that the axial projections (60a, 60c) a plurality of projection groups (62) each having at least one axial fixing projection (60c) and one counter stop projection (60a). Bicycle rear sprocket assembly (30) according to the preamble of Claim 1 or according to one of the preceding claims, characterized in that the Verrastungsgegenformationen (40) having a plurality of pinion spokes (38, 40) having a radially closer to the pinion rotation axis (RA), for transmitting torque from the pinion assembly (30 ) connected to a rear hub hub region (32 a) with a radially further from the pinion rotation axis (RA) located, for power transmission between a bicycle chain (28) and the pinion assembly (30) formed sprocket region (32 b) connect. Bicycle rear sprocket assembly (30) according to Claim 11 characterized in that the sprocket spokes (38, 40) comprise a smaller number of radially inner spokes (38) and a greater number of radially outer spokes (40), the detent formations (40) comprising outer spokes (38). 40), preferably only outer spokes (40). Bicycle rear sprocket assembly (30) according to Claim 11 or 12 , including the Claim 10 characterized in that the sprocket spokes (38, 40) form a plurality of spoke groups (41) each having at least two sprocket spokes (40), each spoke group (41) having a protrusion group (62) for forming one engagement combination each interacts. Bicycle rear sprocket assembly (30) according to Claim 13 , characterized in that in the circumferential direction immediately consecutive sprocket spokes (40), preferably exactly two immediately consecutive sprocket spokes (40), form a spokes group (41). Bicycle rear sprocket assembly (30) according to any one of Claims 11 to 14 , characterized in that the sprocket spokes (38, 40) in addition to their radial gradient component have a leveling component in the circumferential direction such that a radially further inwardly located spoke portion radially outwardly located spoke portion of the same sprocket spoke (38, 40) in the driving direction of rotation (DR) of the pinion assembly (30) leads, wherein particularly preferred sprocket spokes (38, 40) when viewed against the driving direction of rotation (DR) are convexly curved. Bicycle rear sprocket assembly (30) according to the preamble of Claim 1 or according to one of the preceding claims, characterized in that the first subassembly (32) comprises the largest (R1) and the second largest sprocket (R2), wherein the largest (R1) and the second largest sprocket (R2) are formed integrally with each other. Bicycle rear sprocket assembly (30) according to Claim 16 , characterized in that the first subassembly (32) in a radial stiffening region (51) between the foot circuits of the largest (R1) and the second largest pinion (R2) has an axial bead (50) revolving around the pinion rotation axis, which is preferably designed as an axial recess (51). 50a) is formed on the second largest pinion (R2) facing side of the stiffening region (51). Bicycle rear sprocket assembly (30) according to Claim 16 or 17 , including one of Claims 11 to 15 characterized in that the sprocket spokes (40) extend radially outwardly to the sprocket portion (32b) of the largest sprocket (R1), the number of sprocket spokes (40) of the first subassembly (32) being in a radial extent between The root circle and tip circle of the second largest pinion (R2) is half the number of teeth of the second largest pinion (R2). Bicycle rear sprocket assembly (30) according to Claim 18 characterized in that, when the first subassembly (32) is viewed in the axial direction, each pinion spoke (40) and every other tooth (46a) of the second largest pinion (R2) are located at the same circumferential position. Bicycle rear sprocket assembly (30) according to Claim 19 , characterized in that at least in at least one peripheral region at the same circumferential position as pinion spokes (40) located teeth (46a) of the second largest pinion (R2) are formed axially thicker than these immediately adjacent circumferentially teeth (46b). Bicycle rear sprocket assembly (30) according to the preamble of Claim 1 or according to one of the preceding claims, characterized in that the second subassembly (34) has a series of between 6 and 12 axially successive pinions (R3-R12) formed integrally with each other. Bicycle rear sprocket assembly (30) according to Claim 21 characterized in that the second subassembly (34) comprises the third largest sprocket (R3) of the sprocket assembly (30). Bicycle rear sprocket assembly (30) according to Claim 21 or 22 , characterized in that the second subassembly (34) has the smallest sprocket (R12). Bicycle rear sprocket assembly (30) according to any one of Claims 21 to 23 , characterized in that for at least one pairing, preferably for each pairing, of a pinion and its adjacent next smaller pinion of the second subassembly (34), that the pinion connected to the next smaller pinion by integrally formed with two pinions webs (54) is, wherein the number of connecting the two pinion webs (54) is smaller than the number of teeth of the smaller pinion of the pairing. Bicycle rear sprocket assembly (30) according to Claim 24 , characterized in that the number of webs and the number of teeth of the smaller pinion of a pairing of axially immediately adjacent and connected by the webs pinions have a common integer divider. Bicycle rear sprocket assembly (30) according to Claim 24 or 25 , characterized in that in a pairing of two axially immediately adjacent, integrally connected pinions each web is arranged at the same circumferential position on the smaller pinion of the pairing as a tooth of the smaller pinion. Bicycle rear sprocket assembly (30) according to any one of Claims 24 to 26 , characterized in that when the next smaller pinion has a straight number of teeth, the number of bars of the pairing is exactly half the size of the even number of teeth of the next smaller pinion. Bicycle rear sprocket assembly (30) according to Claim 27 characterized in that, when viewing the second subassembly (34) in the axial direction for at least one pairing, preferably for each pairing, of a pinion and the next nearest even numbered pinion of the second subassembly (34), 54) and every other tooth (56a) of the next smaller pinion are located at the same circumferential position. Bicycle rear sprocket assembly (30) according to Claim 26 or after Claim 28 , characterized in that for the at least one pairing at least in a peripheral region that at the same circumferential position as webs (54) located teeth (56a) of the next smaller pinion are formed axially thicker than these immediately adjacent circumferentially teeth (56b). Bicycle rear sprocket assembly (30) according to any one of the preceding claims, characterized in that it comprises eight to fourteen pinions (R1-R12), wherein the smallest pinion (R12) is not more than twelve, preferably not more than ten, preferably exactly has ten teeth and / or that the largest pinion (R1) has not less than 50, preferably not less than 52, more preferably exactly 52 teeth. A bicycle rear sprocket assembly (30) according to any one of the preceding claims, characterized in that on a plurality of even numbered pinion gears (R1-R6, R8-R12), preferably on all pinions (R1-R6, R8-R12) straight number of teeth, at least in a circumferential region in the circumferential direction alternately an axially thicker tooth (36a, 46a, 56a) and an axially thinner tooth (36b, 46b, 56b) are arranged consecutively. Bicycle rear sprocket assembly (30) according to the preamble of Claim 1 or according to one of the preceding claims, characterized in that the smallest pinion at least in a peripheral region, preferably along the entire circumference, alternately axially thicker and axially thinner teeth in the circumferential direction, wherein the next larger pinion indicative lateral tooth flanks of both axially thicker and of axially thinner teeth are located in the peripheral region on a common virtual envelope surface, wherein the axially thicker teeth, starting from the common envelope surface axially further away from the next larger pinion away than the circumferentially arranged therebetween axially thinner teeth. Bicycle rear sprocket assembly (30) according to Claim 32 , characterized in that for a plurality of axially thicker teeth, preferably for all thicker teeth of the smallest pinion, that the next largest tooth pinion nearest lateral tooth flank has a larger dimension in the circumferential direction than the opposite, pointing away from the next larger pinion lateral tooth flank of the same tooth, wherein the lateral tooth flank pointing to the next larger pinion projects beyond the lateral tooth flank facing away from the next largest pinion in the circumferential direction both with its longitudinal end projecting in the direction of drive rotation and with its trailing longitudinal end. Bicycle rear sprocket assembly (30) according to Claim 33 , characterized in that on at least one axially thicker tooth, preferably on a plurality of axially thicker teeth, more preferably on all axially thicker teeth, the transition from the circumferentially longer tooth flank to the circumferentially shorter tooth flank at least one longitudinal end of the tooth, preferably at both longitudinal ends, stepped, preferably carried out in a single stage. A bicycle drive assembly (12) comprising a bicycle chain (28) along its chain longitudinal direction alternately by external and inner link pairs (28a, 28b) interconnected roles and from a with the bicycle chain (28) in driving force transmitting positive engagement engageable bicycle rear sprocket assembly (30) according to one of the preceding claims including the Claim 29 , characterized in that the dimension of the axially thicker teeth (36a, 46a, 56a) in the axial direction is greater than the clear width between the inner plate pairings (28b), so that the axially thicker teeth (36a, 46a, 56a) only in one bounded by outer plates limited tooth entry space of the bicycle chain can fully dive as intended. Bicycle drive assembly (12) after Claim 35 , characterized in that for at least a part of the pinions (R2-R6, R8-R12), in particular with even number of teeth, that when a pinion (R2-R6, R8-R12), in particular with even number of teeth, with the Bicycle chain (28) is in force-transmitting form-fitting engagement, in the axial direction to the next larger pinion (R1-R5, R7-R11) towards a plurality of outer plates, preferably all outer plates, one with the pinion (R2-R6, R8-R12) in form-fitting engagement standing chain longitudinal section a web (54) or a pinion spoke (40) axially opposite.

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