DE102018211536A1 - Carrier for a bicycle sprocket, bicycle sprocket assembly, and bicycle crank set - Google Patents

Abstract

The carrier 44 for a bicycle sprocket 41 includes a sprocket attachment portion 45, a crank assembly attachment portion 46, a pivot structure 47, and a dust cover 37. The sprocket attachment portion 45 and the crank assembly attachment portion 46 are configured to rotate about a rotational center axis C1 , The pivot structure 47 has an axis of rotation P1 which is arranged at a predetermined distance from the center axis of rotation C1. The sprocket attachment portion 45 and the crank assembly attachment portion 46 are configured to rotate about the axis of rotation P1 and the center of rotation C1. The dust cover 37 covers at least the pivot structure 47.

Description

The technology shown here relates to a carrier for a bicycle sprocket, a bicycle sprocket and a bicycle crank set.

Cycling is becoming increasingly popular as a form of leisure and transportation. In addition, cycling has become a very popular competitive sport for amateurs and professionals.

Whether the bike is used for leisure, transportation or competition, the bike industry is constantly improving the various components of the bike. A bicycle component that has been extensively revised is a carrier for a bicycle sprocket, for example a bicycle sprocket comprising the carrier and a bicycle crank set comprising the carrier.

According to the present invention, a carrier for a bicycle sprocket includes a sprocket attachment portion, a crank assembly attachment portion, a swing structure, and a dust cover. The sprocket attachment portion and the crank assembly attachment portion are configured to rotate about a central axis of rotation and transmit torque between the crank assembly attachment portion and the sprocket attachment portion. The swivel structure has an axis of rotation which is arranged at a predetermined distance from the center axis of rotation. The sprocket attachment portion and the crank assembly attachment portion are configured to rotate about the axis of rotation and the axis of rotation. The dust cover covers at least the swivel structure.

With such a carrier according to the present invention, the carrier is able to improve the efficiency of the drive even when a bicycle chain is inclined between a front bicycle sprocket and a rear bicycle sprocket in the transverse direction of a bicycle because of the sprocket attachment portion and the crank assembly -Fastening section are configured to rotate about the axis of rotation of the pivot structure. In addition, the carrier is able to maintain the efficiency of the drive over a long period of time since the dust cover at least covers the swivel structure to prevent contaminants from entering the swivel structure.

According to a preferred aspect of the present invention, the carrier can be configured such that the axis of rotation is not parallel to the center of rotation. With such a carrier, the carrier is capable of reliably rotating the sprocket attachment portion and the crank assembly attachment portion about the axis of rotation of the pivot structure.

According to a further preferred aspect of the present invention, the carrier may further comprise a friction-reducing structure. The friction reducing structure is disposed between the swing structure and the sprocket attachment portion. The friction reducing structure reduces the friction of the rotational movement between the pivot structure and the sprocket attachment section. The dust cover covers the friction-reducing structure. With such a carrier, the carrier is able to maintain the efficiency of the drive for a long period of time because the dust cover covers the friction-reducing structure, so that no contaminants can penetrate into the friction-reducing structure.

According to a further preferred aspect of the present invention, the carrier can be configured such that the friction-reducing structure comprises a ring bearing unit. The ring bearing unit comprises an inner ring and an outer ring. With such a carrier, the carrier is able to maintain the efficiency of the drive for a long period of time because the dust cover covers the friction-reducing structure, so that no contaminants can penetrate into the friction-reducing structure.

According to a further preferred aspect of the present invention, the carrier can be configured such that the inner ring of the ring bearing unit is fixed relative to the swivel structure. With such a carrier, the carrier is able to maintain the efficiency of the drive for a long period of time because the dust cover covers the friction-reducing structure, so that no contaminants can penetrate into the friction-reducing structure.

According to a further preferred aspect of the present invention, the carrier can be configured such that the pivot structure is a unit which is separate from the inner ring of the ring bearing unit. With such a carrier, the weight of the carrier can be reduced.

According to a further preferred aspect of the present invention, the carrier can be configured such that the pivot structure and the inner ring of the ring bearing unit are formed as an integrally one-piece structure. With such a carrier, the weight of the carrier can be reduced.

According to another preferred aspect of the present invention, the carrier be configured so that the axis of rotation is perpendicular to the center of rotation. With such a carrier, the carrier is able to maintain the efficiency of the drive for a long period of time because the dust cover covers the pivot structure to prevent contaminants from entering the pivot structure. In addition, the carrier is capable of reliably rotating the sprocket attachment portion and the crank assembly attachment portion about the axis of rotation of the pivot structure.

According to a further preferred aspect of the present invention, the carrier can be configured such that the axis of rotation is arranged further away from a rear wheel axis of a bicycle than the center axis of rotation. With such a carrier, the carrier is capable of reliably rotating the sprocket attachment portion and the crank assembly attachment portion about the axis of rotation of the pivot structure.

According to another preferred aspect of the present invention, the carrier can be configured so that the dust cover covers the crank assembly mounting portion. With such a carrier, the carrier is able to maintain the efficiency of the drive for a long period of time because the dust cover covers the crank assembly fixing section to prevent contaminants from entering the crank assembly fixing section.

According to another preferred aspect of the present invention, the carrier can be configured so that the dust cover covers the sprocket attachment portion. With such a carrier, the carrier is able to maintain the efficiency of the drive for a long period of time because the dust cover covers the sprocket attachment portion to prevent contaminants from entering the sprocket attachment portion.

According to another aspect of the present invention, a bicycle sprocket assembly includes a sprocket, a bracket, and a pivot structure. The sprocket is configured to rotate about a central axis of rotation and has a plurality of sprocket teeth disposed about a circumference of a sprocket body of the sprocket. The plurality of sprocket teeth includes at least a first tooth with a first chain-engaging axial width with respect to the center axis of rotation and at least a second tooth with a second chain-engaging axial width with respect to the center axis of rotation. The first chain-engaging axial width is larger than the second chain-engaging axial width in an axial direction with respect to the rotation center axis. The carrier includes a sprocket attachment portion and a crank assembly attachment portion. The sprocket attachment portion and the crank assembly attachment portion are configured to rotate about the central axis of rotation and transmit torque between the crank assembly attachment portion and the sprocket attachment portion. The swivel structure has an axis of rotation which is arranged at a predetermined distance from the center axis of rotation. The sprocket attachment portion and the crank assembly attachment portion are configured to rotate about the axis of rotation and the axis of rotation. The twelfth aspect can be combined with any of the first through eleventh aspects.

With such a bicycle sprocket arrangement according to the present invention, the bicycle sprocket arrangement is able to improve the efficiency of the drive, since the bicycle sprocket arrangement comprises the carrier with the pivot structure. In addition, the bicycle sprocket assembly is able to hold a bicycle chain reliably because the plurality of sprocket teeth include the first tooth and the second tooth.

According to a preferred aspect of the present invention, the bicycle sprocket assembly can be configured such that the first chain-engaging axial width is larger than an inner link axial space defined between an opposite pair of inner link plates of a bicycle chain in the axial direction. The first chain-engaging axial width is smaller than an outer link axial space defined between an opposite pair of outer link plates of the bicycle chain in the axial direction. The second chain-engaging axial width is smaller than the inner link axial space. With such a bicycle sprocket assembly, the bicycle sprocket assembly is able to hold the bicycle chain reliably because the plurality of sprocket teeth include the first tooth and the second tooth with the above relationship.

According to a further preferred aspect of the present invention, the bicycle sprocket assembly can be configured such that a first radial length is defined between a first radially outermost tooth tip of the at least one first tooth and the rotational center axis in the radial direction with respect to the rotational center axis. A second radial length is defined in the radial direction between a second radially outermost tooth tip of the at least one second tooth and the center axis of rotation. The first radial length is greater than the second radial length. With such a bicycle sprocket assembly, the bicycle sprocket assembly is capable of making the chain reliable hold because the first radial length is greater than the second radial length.

According to another preferred aspect of the present invention, the bicycle sprocket assembly can be configured such that the first chain-engaging axial width of the at least one first tooth is equal to or greater than 75 percent of the outer link axial space. With such a bicycle sprocket assembly, the bicycle sprocket assembly is able to hold the bicycle chain reliably because the first chain-engaging axial width is equal to or greater than 75 percent of the outer link axial space.

According to a further preferred aspect of the present invention, the bicycle sprocket assembly can be configured such that the at least one first tooth has a first axial tooth tip center line which is offset in the axial direction with respect to the rotational center axis from a first axial tooth center plane of the at least one first tooth. With such a bicycle sprocket arrangement, the bicycle sprocket arrangement is able to hold the bicycle chain reliably even when the bicycle chain is inclined between a front sprocket and a rear sprocket in the transverse direction of a bicycle.

According to a further preferred aspect of the present invention, the bicycle sprocket arrangement can be configured such that the at least one second tooth has a second axial tooth tip center line which is offset in the axial direction with respect to the rotational center axis from a second axial tooth center plane of the at least one second tooth. With such a bicycle sprocket arrangement, the bicycle sprocket arrangement is able to hold the bicycle chain reliably even when the bicycle chain is arranged inclined in the transverse direction of a bicycle between a front sprocket and a rear sprocket.

According to a further preferred aspect of the present invention, the bicycle sprocket assembly can be configured such that the at least one first tooth is asymmetrical with respect to a circumferential tooth center line in a circumferential direction to the rotational center axis. With such a bicycle sprocket arrangement, the bicycle sprocket arrangement is able to hold the bicycle chain reliably.

According to a further preferred aspect of the present invention, the bicycle sprocket arrangement can be configured such that the at least one first tooth is symmetrical with respect to a circumferential tooth center line in a circumferential direction to the rotational center axis. With such a bicycle sprocket assembly, it is possible to efficiently manufacture the bicycle sprocket assembly.

According to a further preferred aspect of the present invention, the bicycle sprocket arrangement can be configured such that the at least one first tooth is asymmetrical with respect to a first axial tooth center plane in the axial direction with respect to the center axis of rotation. With such a bicycle sprocket arrangement, the bicycle sprocket arrangement is able to hold the bicycle chain reliably.

According to a further preferred aspect of the present invention, the bicycle sprocket arrangement can be configured such that the at least one first tooth is symmetrical with respect to a first axial tooth center plane in the axial direction with respect to the center axis of rotation. With such a bicycle sprocket assembly, it is possible to efficiently manufacture the bicycle sprocket assembly.

According to another preferred aspect of the present invention, the bicycle sprocket assembly can be configured such that the carrier has a dust cover that at least covers the pivot structure. With such a bicycle sprocket arrangement, the bicycle sprocket arrangement is able to maintain the efficiency of the drive over a long period of time since the dust cover at least covers the swivel structure in order to prevent contaminants from penetrating into the swivel structure.

According to another aspect of the present invention, a bicycle crank set includes a crank assembly, a bicycle sprocket assembly, and a dust cover. The crank assembly includes a first crank arm, a second crank arm, and a crank shaft. The crankshaft connects the first crank arm and the second crank arm in the assembled state of the crank arrangement. The bicycle sprocket assembly includes a sprocket and a carrier. The sprocket includes a variety of sprocket teeth. The plurality of sprocket teeth of the sprocket are arranged around a circumference of a sprocket body of the sprocket. The sprocket has an opening through which the crankshaft extends. The sprocket is configured to rotate about a central axis of rotation. The carrier comprises a swivel structure with an axis of rotation and a dust cover that covers at least the swivel structure. The chain wheel is fastened to the carrier so that it can rotate about the central axis of rotation, so that the chain wheel can be rotated about the axis of rotation. The axis of rotation is arranged at a predetermined distance from the center of rotation. The twenty-third aspect can be with each of the first to twenty-second aspects can be combined.

With such a bicycle crank set according to the present invention, the bicycle crank set is able to improve the efficiency of the drive even when a bicycle chain between a front bicycle sprocket and a rear bicycle sprocket is inclined in the transverse direction of a bicycle because the sprocket is configured to itself to rotate the axis of rotation. In addition, the bicycle crank set is able to maintain the efficiency of the drive for a long period of time, since the dust cover at least covers the swivel structure in order to prevent contaminants from penetrating into the swivel structure.

• 1 eine Seitenansicht eines Fahrrades nach einer Ausführungsform der vorliegenden Erfindung ist;
• 2 eine obere Ansicht eines Fahrradkurbelsatzes von außen nach der Ausführungsform der vorliegenden Erfindung ist;
• 3 eine perspektivische Ansicht eines Fahrradkurbelsatzes nach der Ausführungsform der vorliegenden Erfindung ist;
• 4 eine Seitenansicht eines vorderen Fahrradkettenrades nach der Ausführungsform der vorliegenden Erfindung ist;
• 5 eine obere Ansicht einer Fahrradkette von radial außen nach der Ausführungsform der vorliegenden Erfindung ist;
• 6A eine vergrößerte obere Ansicht der Fahrradkette von radial außen nach der Ausführungsform der vorliegenden Erfindung ist;
• 6B eine vergrößerte obere Ansicht der Fahrradkette von radial außen nach einer Variante der Ausführungsform der vorliegenden Erfindung ist;
• 7A eine vergrößerte Seitenansicht des vorderen Fahrradkettenrades nach der Ausführungsform der vorliegenden Erfindung ist;
• 7B eine vergrößerte Seitenansicht des vorderen Fahrradkettenrades nach einer Variante der Ausführungsform der vorliegenden Erfindung ist;
• 8 eine Seitenansicht des Fahrradkurbelsatzes ohne Staubabdeckung nach der Ausführungsform der vorliegenden Erfindung ist;
• 9A eine Seitenansicht einer ersten Staubabdeckung der Staubabdeckung von einem Fahrradrahmen nach der Ausführungsform der vorliegenden Erfindung ist;
• 9B eine Seitenansicht einer zweiten Staubabdeckung der Staubabdeckung von einem Fahrradrahmen nach der Ausführungsform der vorliegenden Erfindung ist; und
• 10 eine obere Ansicht eines Antriebsteils zur Erklärung des Zusammenwirkens der Fahrradkette zwischen dem vorderen Fahrradkettenrad und einem hinteren Fahrradkettenrad ist.

A more complete understanding of the invention and many of the advantages associated therewith are readily achieved as they can be better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which:

• 1 3 is a side view of a bicycle according to an embodiment of the present invention;
• 2 4 is a top view of a bicycle crank set from the outside according to the embodiment of the present invention;
• 3 Fig. 3 is a perspective view of a bicycle crank set according to the embodiment of the present invention;
• 4 3 is a side view of a front bicycle sprocket according to the embodiment of the present invention;
• 5 4 is a radially outer top view of a bicycle chain according to the embodiment of the present invention;
• 6A Fig. 3 is an enlarged top view of the bicycle chain from the radially outside according to the embodiment of the present invention;
• 6B an enlarged top view of the bicycle chain from the radially outer side according to a variant of the embodiment of the present invention;
• 7A 12 is an enlarged side view of the front bicycle sprocket according to the embodiment of the present invention;
• 7B Figure 3 is an enlarged side view of the front bicycle sprocket according to a variant of the embodiment of the present invention;
• 8th 3 is a side view of the bicycle crank set without dust cover according to the embodiment of the present invention;
• 9A 12 is a side view of a first dust cover of the dust cover from a bicycle frame according to the embodiment of the present invention;
• 9B 12 is a side view of a second dust cover of the dust cover from a bicycle frame according to the embodiment of the present invention; and
• 10 a top view of a drive member for explaining the interaction of the bicycle chain between the front bicycle sprocket and a rear bicycle sprocket.

Selected embodiments will now be described with reference to the accompanying drawings, wherein like reference numerals designate corresponding or identical elements in the different drawings.

As in 1 shown includes a bicycle 1 a bicycle chain 9 , a frame 11 , a handle 13 , Front and rear wheels 17 . 19 , a front fork 20 , a switching device 24 and a drive part 25 ,

The handle 13 is on the front wheel fork 20 attached. The front fork 20 is rotatable on the frame 11 attached. The front wheel 17 is rotatable on the front fork via a front wheel hub 20 attached. The rear wheel 19 is via a rear hub 31 rotatable on a rear part of the frame 11 attached. On the front wheel 17 is a front tire 17a attached. A rear tire 19a is on the rear wheel 19 attached.

The drive part 25 essentially includes a bicycle crank set 27 and a rear bicycle sprocket assembly 29 , In particular, the drive part comprises 25 essentially the bicycle crank set 27 who have favourited Rear Hub 31 and the rear bicycle sprocket assembly 29 ,

The rear hub 31 will be at the back of the frame 11 assembled. The rear bicycle sprocket assembly 29 is from the rear hub 31 rotatably mounted. The rear bicycle sprocket assembly 29 contains a variety of bicycle sprockets 29a , each with the bike chain 9 come into engagement.

As in 1 shown is the bicycle crank set 27 on a lower part of the frame 11 rotatably mounted. As in 1 and 2 shown, includes the bicycle crank set 27 a crank assembly 33 and a front one Fahrradkettenradanordnung 35 (An example of a bicycle sprocket assembly).

As in 2 shown includes the crank assembly 33 a first crank arm 33a , a second crank arm 33b and a crankshaft 33c , The first crank arm 33a is at one end of the crankshaft 33c attached. The second crank arm 33b is on the other end of the crankshaft 33c attached. The crankshaft 33c connects the first crank arm 33a and the second crank arm 33b in the assembled state of the crank assembly 33 , The crankshaft 33c is on a lower part of the frame 11 pivoted (see 1 ).

As in 2 illustrated includes the front bicycle sprocket assembly 35 (an example of a bicycle sprocket assembly) a front bicycle sprocket 41 (an example of a sprocket) and a carrier 44 , In particular, as in 3 illustrated includes the front bicycle sprocket assembly 35 the front bicycle sprocket 41 (an example of a sprocket), the carrier 44 and a swivel structure 47 , In particular, the front bicycle sprocket assembly includes 35 at least one front bicycle sprocket 41 , the carrier 44 and a swivel structure 47 , In this embodiment, an example is explained in which a total number of the front bicycle sprocket 41 is one. The carrier 44 includes a dust cover 37 that have at least the swivel structure 47 covers.

As in 1 shown, the front bicycle sprocket comes 41 with the bike chain 9 engaged. The front bicycle sprocket 41 is configured to center around a rotational axis C1 to turn. The axis of rotation C1 corresponds to a central axis of rotation of the bicycle crank set 27 , for example a central axis of rotation of a crank arrangement 33 and a rotational center axis of the front bicycle sprocket assembly 35 in an assembled state in which the bicycle crank set 27 on the bike 1 is mounted.

As in 2 and 3 shown is the front bicycle sprocket 41 about the central axis of rotation C1 rotatable on the carrier 44 attached so that the front bicycle sprocket 41 is configured to rotate around an axis of rotation P1 of the carrier 44 to turn.

As in 3 shown, includes the front bicycle sprocket 41 a variety of sprocket teeth 42 , In particular, the front bicycle sprocket includes 41 a sprocket body 43 and the variety of sprocket teeth 42 extending from the sprocket body 43 radially outward with respect to the axis of rotation C1 extend. The front bicycle sprocket 41 has an opening 41 a through which the crankshaft extends 33c extends. The carrier 44 is partially in the opening 41a arranged.

The sprocket body 43 is essentially ring-shaped. The opening 41a is on the sprocket body 43 provided. The opening 41a is by an inner peripheral surface of the sprocket body 43 educated. The opening 41a passes through the sprocket body 43 in the axial direction with respect to the central axis of rotation C1 ,

The variety of sprocket teeth 42 comes with the bike chain 9 engaged. The variety of sprocket teeth 42 is around a circumference of the sprocket body 43 of the front bicycle sprocket 41 arranged. In particular, each of the plurality of sprocket teeth projects 42 from the circumference of the sprocket body 43 of the front bicycle sprocket 41 out. In the 3 shown variety of sprocket teeth 42 is drawn in a simplified form and is a detail of an example of the plurality of sprocket teeth 42 is in 4 shown.

As in 4 shown includes the plurality of sprocket teeth 42 at least a first tooth 42a and at least one second tooth 42b , As in 5 shown, includes the bicycle chain 9 a variety of outer link plates 9a , a variety of inner link plates 9b and a variety of chain rollers 9c , The at least one first tooth 42a is designed to be between the opposite pair of outer link plates 9a the bicycle chain 9 comes into engagement.

In this embodiment, each of a plurality of first teeth 42a on the circumference of the sprocket body 43 of the front bicycle sprocket 41 at a predetermined distance in the circumferential direction with respect to the central axis of rotation C1 educated. Each of the variety of first teeth 42a is against the center of rotation C1 from radially outside in the radial direction with respect to the center of rotation C1 formed in an essentially positive form.

According to the present invention, the shape of the first teeth 42a but not limited to this embodiment. For example, the shape of the first teeth 42a seen from the radial outside in the radial direction, be a polygonal shape such as hexagonal, octagonal or oval.

As in 5 shown, the at least one first tooth 42a a first chain engaging axial width W1 related to the center of rotation C1 , In this embodiment, each includes a plurality of first teeth 42a the first chain-engaging axial width W1 related to the center of rotation C1 , Alternatively, some of the first teeth 42a another chain engaging width than the first chain engaging width W1 include.

The first chain-engaging axial width W1 corresponds to a width of each of the plurality of first teeth 42a in the axial direction with respect to the center of rotation C1 , In particular, the first chain-engaging axial width W1 an axial length of the widest part of the first tooth 42a in the axial direction with respect to the central axis of rotation C1 ,

The first chain-engaging axial width W1 is smaller than an outer link axial space S1 that between the opposite pair of outer link plates 9a the bicycle chain 9 in the axial direction with respect to the center of rotation C1 is defined.

The first chain-engaging axial width W1 is larger than an inner link axial space S2 between an opposing pair of inner link plates 9b a bicycle chain 9 in the axial direction with respect to the central axis of rotation C1 is defined.

The first chain-engaging axial width is preferred W1 from each of the first teeth 42a equal to or greater than 75 percent of an axial width WC1 of the outer link axial space S1 , In other words, the first chain-engaging axial width is preferred W1 of the at least one first tooth 42a equal to or greater than 75 percent of the outer link axial space S1 , The first chain-engaging axial width is more preferred W1 of the at least one first tooth 42a equal to or greater than 80 percent of the outer link axial space S1 ,

As in 5 shown is the at least one second tooth 42b designed to mate with the opposite pair of inner link plates 9b the bicycle chain 9 comes into engagement. In this embodiment, each is a plurality of second teeth 42b on the circumference of the sprocket body 43 of the front bicycle sprocket 41 between the adjacent first teeth 42a in the circumferential direction with respect to the central axis of rotation C1 educated. Each of the variety of second teeth 42b is against the center of rotation C1 from radially outside in the radial direction with respect to the center of rotation C1 formed in a substantially negative form. According to the present invention, the shape of the second teeth 42b but not limited to this embodiment.

The at least one second tooth 42b includes a second chain engaging axial width W2 related to the center of rotation C1 , In this embodiment, each includes a plurality of second teeth 42b the second chain engaging axial width W2 related to the center of rotation C1 , Alternatively, some of the second teeth 42b a chain engaging width other than the second chain engaging width W2 include.

The second chain-engaging axial width W2 corresponds to a width of each of the plurality of second teeth 42b in the axial direction with respect to the central axis of rotation C1 , In particular, the second chain-engaging axial width W2 an axial length of the widest part of the second tooth 42b in the axial direction with respect to the central axis of rotation C1 ,

The second chain-engaging axial width W2 is smaller than the inner link axial space S2 , In particular, the second chain-engaging axial width W2 smaller than an axial width WC2 of the inner link axial space S2 , The axial width WC2 of the inner link axial space S2 is smaller than the axial width WC1 of the outer link axial space S1 ,

The second chain-engaging axial width W2 is smaller than the first chain-engaging axial width W1 in the axial direction with respect to the central axis of rotation C1 , In other words, the first chain engaging axial width W1 is larger than the second chain-engaging axial width W2 in the axial direction with respect to the central axis of rotation C1 ,

As in 6A shown is the at least one first tooth 42a with respect to a first axial tooth center plane CA1 in the axial direction with respect to the central axis of rotation C1 asymmetric.

The at least one first tooth 42a has a first axial tooth tip centerline TC1 on that opposite the first axial tooth center plane CA1 of the at least one first tooth 42a in the axial direction with respect to the central axis of rotation C1 is offset. For example, the first axial tooth tip center line TC1 from the first axial tooth center plane CA1 of the at least one first tooth 42a to the first crank arm 33a in the axial direction with respect to the central axis of rotation C1 be offset in a state in which the bicycle crank set 27 on the frame 11 is attached.

The first axial tooth center plane CA1 is perpendicular to the center of rotation C1 and passes through a center of the widest part of the first tooth 42a in the axial direction with respect to the central axis of rotation C1 ,

As in 7A shown is the at least one first tooth 42a with respect to a first circumferential tooth center line CC1 in the circumferential direction with respect to the rotational center axis C1 asymmetric.

The first circumferential tooth centerline CC1 extends between the center axis of rotation C1 and a first revolving center CP1 in radial direction with respect to the central axis of rotation C1 ,

The first revolving center CP1 is defined by a center point of a segment, the tooth root points CPa . CPb combines. Each of the tooth base points CPa . CPb is on a tooth base between the first tooth 42a and each of the second teeth 42b next to the first tooth 42a in the circumferential direction with respect to the rotational center axis C1 Are defined.

In this embodiment, each of the plurality of first teeth 42a asymmetrical with respect to the first axial center plane of the tooth CA1 in the axial direction with respect to the central axis of rotation C1 (please refer 6A) , Each of the variety of first teeth 42a is asymmetrical with respect to the first circumferential tooth center line CC1 in the circumferential direction with respect to the rotational center axis C1 (please refer 7A) , The first axial tooth centerline TC1 from each of the variety of first teeth 42a is from the first axial tooth center plane CA1 from each of the variety of first teeth 42a offset (see 6A) ,

As in 6B shown, the at least one first tooth 42a with respect to the first axial tooth center plane CA1 in the axial direction with respect to the central axis of rotation C1 be symmetrical. As in 7B shown, the at least one first tooth 42a symmetrical with respect to the first circumferential tooth center line CC1 in the circumferential direction with respect to the rotational center axis C1 his.

As in 6A shown is the at least one second tooth 42b with respect to a second axial tooth center plane CA2 in the axial direction with respect to the central axis of rotation C1 asymmetric.

The at least one second tooth 42b has a second axial tooth tip centerline TC2 on that opposite to the second axial tooth center plane CA2 of the at least one second tooth 42b in the axial direction to the central axis of rotation C1 is offset. The second axial tooth tip center line is preferably TC2 from the second axial tooth center plane CA2 in the same axial direction as the first tooth tip 42c added.

For example, the second axial tooth tip center line TC2 from the second axial tooth center plane CA2 of the at least one second tooth 42b to the first crank arm 33a in the axial direction with respect to the center of rotation C1 be offset when the bicycle crank set 27 on the frame 11 is attached.

The second axial tooth center plane CA2 is perpendicular to the center of rotation C1 and passes through a center of the widest part of the second tooth 42b in the axial direction with respect to the central axis of rotation C1 ,

As in 7A shown is the at least one second tooth 42b with respect to a second circumferential tooth center line CC2 in the circumferential direction to the central axis of rotation C1 asymmetric. The second circumferential tooth centerline CC2 extends between the center axis of rotation C1 and a second rotating center CP2 in the radial direction with respect to the central axis of rotation C1 ,

The second rotating center CP2 is defined by a center point of a segment, the tooth root points CPa . CPb combines. Each of the tooth base points CPa . CPb is on the tooth base between the second tooth 42b and each of the first teeth 42a next to the second tooth 42b in the circumferential direction with respect to the central axis of rotation C1 Are defined.

In this embodiment, each of the plurality of second teeth is 42b with respect to the second axial tooth center plane CA2 in the axial direction with respect to the center of rotation C1 asymmetrical (see 6A) , Each of the variety of second teeth 42b is asymmetrical with respect to the second circumferential tooth center line CC2 in the axial direction with respect to the central axis of rotation C1 (please refer 7A) , The second axial tooth centerline TC2 from each of the plurality of second teeth 42b is from the second axial tooth center plane CA2 offset (see 6A) ,

As in 6B shown, the at least one second tooth 42b symmetrical with respect to the second axial center plane of the tooth CA2 in the axial direction with respect to the central axis of rotation C1 his. As in 7B shown, the at least one second tooth 42b symmetrical with respect to the second circumferential tooth center line CC2 in the circumferential direction with respect to the rotational center axis C1 his.

As in 4 shown is a first radial length R1 between a first radially outermost tooth tip 42e of the at least one first tooth 42a and the central axis of rotation C1 in the radial direction with respect to the central axis of rotation C1 Are defined. A second radial length R2 is between a second radially outermost tooth tip 42f of the at least one second tooth 42b and the central axis of rotation C1 in the radial direction with respect to the central axis of rotation C1 Are defined. The second radial length R2 is less than the first radial length R1 , In other words, the first radial length R1 is greater than the second radial length R2 ,

As in 3 and 8th shown includes the carrier 44 for the front bicycle sprocket 41 a swivel structure 47 with the axis of rotation P1 , The carrier 44 for the front bicycle sprocket 41 in particular includes a sprocket attachment portion 45 and a crank assembly fixing section 46 , In particular, the carrier comprises 44 for the front bicycle sprocket 41 the sprocket mounting section 45 , the crank assembly mounting section 46 who have favourited Swivel Structure 47 with the axis of rotation P1 and the dust cover 37 , The carrier 44 also includes a friction-reducing structure 48 , The carrier 44 also includes a locking structure 49 ,

The sprocket attachment sections 45 and the crank assembly mounting section 46 are configured to center around the rotational axis C1 to rotate and torque between the crank assembly mounting section 46 and the sprocket mounting section 45 transferred to. The sprocket attachment sections 45 and the crank assembly mounting section 46 are configured to rotate around the axis of rotation P1 and the center of rotation C1 to turn.

The sprocket attachment sections 45 are on the front bicycle sprocket 41 attached. For example, the sprocket attachment sections 45 on the sprocket body 43 of the front bicycle sprocket 41 attached. In particular, the sprocket attachment sections 45 each on a plurality of first protruding parts 44a the sprocket body 43 of the front bicycle sprocket 41 attached.

As in 8th shown includes the sprocket mounting portion 45 a pair of plates 45a and a wall section 45b , The pair of plates 45a stands in the axial direction with respect to the center of rotation C1 across from. The wall section 45b extends between the pair of plates 45a in the axial direction with respect to the central axis of rotation C1 ,

Each of the first parts above 44a protrudes from an inner peripheral surface of the sprocket body 43 against the center of rotation C1 in the radial direction with respect to the central axis of rotation C1 in front. Each of the first parts above 44a is between the pair of plates 45a in the axial direction with respect to the central axis of rotation C1 arranged.

The first part above 44a lies in the direction of rotation in relation to the central axis of rotation C1 on the wall section 45b on. The direction of rotation corresponds to a direction of rotation in which the front bicycle sprocket 41 turns to the bike 1 drive.

The front bicycle sprocket 41 through the sprocket mounting section 45 (Pair of plates 45a and wall section 45b) in the axial direction with respect to the central axis of rotation C1 positioned.

As in 3 shown includes the crank assembly mounting portion 46 a central axis C3 parallel to the center of rotation C1 , The crank assembly attachment section 46 is on the crank assembly 33 attached. For example, the crank assembly attachment section 46 on the first crank arm 33a the crank assembly 33 attached. In particular, the crank assembly attachment portion 46 on a second protruding part 33d of the first crank arm 33a attached so that a pedal torque between the crank assembly 33 and the front bicycle sprocket is transmitted.

The crank assembly attachment section 46 is essentially down-to-earth tubular. The second part above 33d protrudes from the first crank arm 33a in the axial direction with respect to the central axis of rotation C1 (for example central axis C3 ) out.

The second part above 33d is preferably essentially cylindrical. The second part above 33d is in the crank assembly mounting section 46 used. For example, the second part above 33d via a sealing element 33e into an inner peripheral part of the crank assembly fixing portion 46 brought in. Alternatively, the second protruding portion may be substantially down-to-earth tubular during the crank assembly attachment portion 46 is substantially cylindrical, so that the crank assembly attachment portion 46 in the second part above 33d is arranged.

In this state, the crank assembly fixing section is 46 compared to the second part above 33d in the axial direction with respect to the central axis of rotation C1 slidable while the swivel structure 47 is working.

The above sprocket attachment sections 45 and the crank assembly mounting section 46 are through a mounting bracket 50 connected with each other. The fastener body 50 is essentially ring-shaped. The sprocket attachment sections 45 and the crank assembly mounting section 46 are on an outer peripheral part of the fastening body 50 at a predetermined distance in the circumferential direction to the rotational center axis C1 provided.

The sprocket attachment sections 45 , the crank assembly mounting section 46 and the mounting body 50 are in the following Description as a fastener 51 characterized.

The swivel structure 47 has the axis of rotation P1 by a predetermined distance from the center of rotation C1 arranged away. For example, the axis of rotation P1 further from a rear wheel axle C2 of a bike 1 located remotely as the rotational center axis C1 (please refer 10 ). In particular, the axis of rotation is C1 between the axis of rotation P1 and the rear wheel axle C2 arranged.

The axis of rotation P1 does not extend parallel to the center of rotation C1 , In this embodiment, the axis of rotation extends P1 perpendicular to the axis of rotation C1 ,

The swivel structure 47 includes a pivot bearing 52 , a rotatably mounted element 53 and a pivot 54 , The pivot bearing 52 is on the frame 11 assembles and supports the rotatably mounted element 53 over the pivot 54 swiveling off.

The pivot bearing 52 includes a first main body 52a and a first axle bearing part 52b , The first main body 52a is essentially tubular. The crankshaft 33c passes through an inner peripheral part of the first main body 52a ,

The first main body 52a includes a small diameter section 52c and a large diameter section 52d , The small diameter section 52c is on the frame 11 mounted, for example the lower part of the frame 11 (i.e. a bottom bracket suspension part of the bike frame 11 ). The large diameter section 52d has a larger outer diameter than the small diameter section 52c ,

The first axle bearing part 52b is on the first main body 52a provided. For example, the first axle bearing part 52b on an outer peripheral surface of the large diameter portion 52d of the first main body 52a formed.

The first axle bearing part 52b is a predetermined distance from the center of rotation C1 arranged away. For example, the first axle bearing part 52b further from the rear wheel axle C2 of the bike 1 removed as the center of rotation C1 arranged. In particular, the first axle bearing part 52b in front of the center of rotation C1 arranged.

The first axle bearing part 52b is essentially tubular. The first axle bearing part 52b does not extend parallel to the center of rotation C1 , In this embodiment, the first axle bearing part 52b an elongated shape in one direction. The first axle bearing part 52b extends perpendicular to the center of rotation C1 ,

As in 3 shown, the rotatably mounted element 53 over the pivot 54 on the pivot bearing 52 pivoted. The rotatably mounted element 53 is due to the friction-reducing structure 48 assembled.

The rotatably mounted element 53 includes a second main body 53a and second axle bearing parts 53b , The second main body 53a is essentially ring-shaped. The second main body 53a is outside the first main body 52a arranged. The second main body 53a is due to the friction-reducing structure 48 attached, for example an inner ring 48a1 a ring bearing unit 48a (see below) in a press-fit manner.

The second axle bearing parts 53b are on the second main body 53a provided. For example, the second axle bearing parts 53b as a unitary, one-piece element on an inner peripheral surface of the second main body 53a formed.

Each of the second axle bearing parts 53b is arranged at a predetermined distance. The first axle bearing part 52b of the pivot bearing 52 is between the second axle bearing parts 53b in a direction along the axis of rotation P1 arranged.

As in 3 shown, the pivot has 54 an elongated shape in one direction. For example, the pivot 54 formed essentially cylindrical. The pivot 54 is rotatable on the pivot bearing 52 stored and on the rotatably mounted element 53 attached. The pivot is specific 54 in an inner peripheral part of the first axle bearing part 52b arranged and on the second axle bearing parts 53b attached.

The pivot 54 encompasses the axis of rotation P1 in a state in which the axis of rotation 54 in the inner peripheral part of the first axle bearing part 52b located and on the second axle bearing parts 53b is attached. The axis of rotation P1 runs through a center of the pivot 54 and extends in the direction of the pivot 54 ,

The friction-reducing structure 48 reduces the friction of the rotary movement between the swivel structure 47 and the sprocket attachment sections 45 , In particular, reduces the friction-reducing structure 48 the friction of the rotational movement between the swivel structure 47 and the fastener 51 ,

The friction-reducing structure 48 is between the swivel structure 47 and the sprocket fixing portions 45 arranged. In particular, the friction-reducing structure 48 between the swivel structure 47 and the fastener 51 arranged. The fastener 51 includes the sprocket mounting sections 45 , the crank assembly mounting section 46 and the mounting body 50 ,

The friction-reducing structure 48 includes the ring bearing unit 48a , The ring bearing unit 48a encompasses the inner ring 48a1 and an outer ring 48a2 , The ring bearing unit 48a also includes a large number of rolling elements 48a3 between the inner ring 48a1 and the outer ring 48a2 are arranged.

The inner ring 48a1 the ring bearing unit 48a is one of the swivel structure 47 separate unit. In other words, the swivel structure 47 is one from the inner ring 48a1 the ring bearing unit 48a separate unit. The swivel structure 47 and the inner ring 48a1 the ring bearing unit 48a can be formed as an integrally one-piece structure. Namely the swivel structure 47 and the inner ring 48a1 the ring bearing unit 48a can be designed as a single, one-piece element.

The inner ring 48a1 the ring bearing unit 48a is relative to the swivel structure 47 attached. For example, the inner ring 48a1 the ring bearing unit 48a opposite the rotatably mounted element 53 (the second main body 53a) the swivel structure 47 attached in a press-fit manner.

The outer ring 48a2 is radially outside of the inner ring 48a1 arranged. The outer ring 48a2 the ring bearing unit 48a is relative to the fastener 51 attached. For example, the outer ring 48a2 the ring bearing unit 48a opposite the mounting body 50 the fastener 51 attached in a press-fit manner.

The variety of rolling elements 48a3 is between the inner ring 48a1 and the outer ring 48a2 in the radial direction to the central axis of rotation C1 arranged. The outer ring rotates in this state 48a2 relative to the inner ring 48a1 about the multitude of rolling elements 48a3 ,

As in the 3 and 8th is shown, the locking structure 49 to limit an angle of rotation of the rotatably mounted element 53 opposite the pivot bearing 52 used. As in 8th shown, there is the locking structure 49 between the pivot bearing 52 and the rotatably mounted element 53 ,

The locking structure 49 includes a first lead 49a , a second lead 49b and a connector 49c , The first lead 49a is on the rotatably mounted element 53 provided. For example, the first tab 49a integrally on the inner peripheral surface of the rotatably supported member 53 (the second main body 53a) formed as a single, one-piece element.

The second lead 49b is on the pivot bearing 52 provided. For example, the second projection 49b integral on the outer peripheral surface of the rotary bearing 52 (the large diameter section 52d of the first main body 52a) formed as a single, one-piece element. The second lead 49b is the first lead 49a in the radial direction to the central axis of rotation C1 across from.

The connecting element 49c is between the first ledge 49a and the second lead 49b arranged and connects the first projection 49a and the second lead 49b , For example, the connecting element 49c an elastic element. The connecting element 49c can be a spring element.

The connecting element 49c deforms elastically due to an axial offset of the first projection 49a and the second projection 49b relative to each other while the rotatable element 53 relative to the pivot bearing 52 rotates.

When the connecting element is deformed 49c the connector works 49c so that an opposite state is restored in which the first projection 49a and the second lead 49b in the radial direction with respect to the center of rotation C1 are opposite. For example, if the angle of rotation of the swivel structure 47 decreases, become the first lead 49a and the second lead 49b by an elastic restoring force of the connecting element 49c restored in the opposite state.

As in 1 and 3 shown covers the dust cover 37 at least the swivel structure 47 from. The dust cover 37 can further reduce the friction structure 48 cover. The dust cover 37 can further the crank assembly mounting section 46 cover. The dust cover 37 can continue the sprocket attachment section 45 cover. In other words, the dust cover 37 can be at least one of the swivel structure 47 , the friction-reducing structure 48 , the crank assembly mounting section 46 and the sprocket mounting section 45 cover.

The dust cover 37 can be at least one of the swivel structure 47 , the friction-reducing structure 48 , the crank assembly mounting section 46 and the sprocket attachment section 45 cover. Preferably, the dust cover 37 all from the swivel structure 47 , the friction-reducing structure 48 , the crank assembly mounting section 46 and the sprocket mounting section 45 cover.

The dust cover 37 is attached to the front bicycle sprocket 41 appropriate. Preferably the dust cover 37 with at least one of an adhesive, a snap lock and a mechanical lock, such as a rivet and a bolt, on the front bicycle sprocket 41 attached. The dust cover 37 consists preferably of an elastic material such as synthetic rubber and polyurethane rubber.

As in 3 shown, there is dust cover 37 from a first dust cover 38 and a second dust cover 40 , The first dust cover 38 is essentially down-to-earth tubular. The first dust cover 38 includes the swivel structure 47 , the anti-friction structure 48 , the crank assembly mounting section 46 and the sprocket attachment portions 45 from a bicycle frame side in this embodiment.

In particular, the first dust cover includes 38 the large diameter section 52d of the pivot bearing 52 , the anti-friction structure 48 , the crank assembly mounting section 46 and the sprocket attachment sections 45 from the bike frame side. The first dust cover 38 is located between the front bicycle sprocket 41 and the frame 11 in the axial direction to the central axis of rotation C1 , The first dust cover 38 is located radially outside of the large diameter section 52d of the pivot bearing 52 (please refer 9A) ,

The first dust cover 38 is on the front bicycle sprocket 41 attaches and rotates with the front bicycle sprocket 41 , The first dust cover 38 rotates relative to the large diameter section 52d the swivel structure 47 via the ring bearing unit 48a , The first dust cover 38 can on the crank assembly mounting section 46 of the carrier 44 so that they are relative to the large diameter section 52d the swivel structure 47 rotates.

In this embodiment, as in FIGS 1 and 3 shown the first dust cover 38 on the sprocket body 43 of the front bicycle sprocket 41 between the front bicycle sprocket 41 and the frame 11 in the axial direction to the central axis of rotation C1 appropriate. As in 9A shown, is a gap in this embodiment G1 between a first cavity 38a the first dust cover 38 and the large diameter section 52d the swivel structure 47 in the radial direction with respect to the central axis of rotation C1 provided. The first hollow area 38a is located on a lower part of the first dust cover 38 ,

As in 3 shown is the second dust cover 40 formed essentially down-to-earth tubular. The second dust cover 40 in this embodiment comprises the pivot structure 47 , the anti-friction structure 48 , the crank assembly mounting section 46 and the sprocket attachment sections 45 from a first crank arm side.

The second dust cover 40 is located between the front bicycle sprocket 41 and the first crank arm 33a the crank assembly 33 in the axial direction to the central axis of rotation C1 , The second dust cover 40 is radially outside the crankshaft 33c arranged (see 9B) ,

The second dust cover 40 is attached to the front bicycle sprocket 41 attached and rotates with the front bicycle sprocket 41 , The second dust cover 40 turns over the ring bearing unit 48a relative to the pivot bearing 52 the swivel structure 47 ,

In this embodiment, the second dust cover is 40 on the sprocket body 43 of the front bicycle sprocket 41 between the front bicycle sprocket 41 and the first crank arm 33a the crank assembly 33 in the axial direction with respect to the central axis of rotation C1 appropriate. The crankshaft 33c passes through a second cavity 40a that is on a lower part of the second dust cover 40 is provided. The second part above 33d of the first crank arm 33a passes through a third cavity 40b that is at the bottom of the second dust cover 40 is provided. One of the first dust covers 38 and second dust cover 40 can be omitted as needed, for example to save weight.

As a rule, the bicycle chain moves 9 when switching the bicycle chain 9 from one of the bicycle sprockets 29a to another of the bicycle sprockets 29a through a rear derailleur. As in 10 shown, the helix angle increases AG1 between the bike chain 9 and a chain line CL when the bike chain 9 on a smallest sprocket 29a too moved. The bike chain moves 9 on a largest sprocket 29a to, the helix angle increases AG2 between the bike chain 9 and the chain line CL ,

In this embodiment, the angle of inclination increases AG1 or AG2 the front bicycle sprocket assembly 35 due to the pivot structure 47 relative to a median longitudinal plane LCP of the frame 11 ,

This makes the front bicycle sprocket assembly 35 able to perform the switching operation of the rear derailleur reliably and improve the efficiency of the drive, even if the helix angle AG1 or AG2 increases.

The front bicycle sprocket assembly 35 can be the first tooth 42a and the second tooth 42b include. The first tooth 42a comes between an opposite pair of outer link plates 9a the bicycle chain 9 engaged. The second tooth 42b comes with the opposite pair of inner link plates 9b the bicycle chain 9 engaged. The first chain-engaging axial width W1 of the first tooth 42a is larger than the second chain-engaging axial width W2 of the second tooth 42b ,

This allows the front bicycle sprocket assembly 35 improve the efficiency of the drive and the bicycle chain 9 hold reliably.

Also the first axial tooth tip center line TC1 of the first tooth 42a can from the first axial tooth center plane CA1 of the first tooth 42a be offset. The second axial tooth centerline TC2 of the second tooth 42b can from the second axial tooth center plane CA2 of the second tooth 42b be offset.

This allows the front bicycle sprocket assembly 35 improve the efficiency of the drive and the bicycle chain 9 hold reliably even when the bike chain 9 between the front bicycle sprocket 41 and the rear bicycle sprocket 29a is inclined in the transverse direction of a bicycle.

The dust cover 37 can the swivel structure 47 , the anti-friction structure 48 , the crank assembly mounting section 46 and the sprocket attachment sections 45 cover. This makes the bicycle crank set 27 able to prevent the ingress of foreign bodies and maintain the efficiency of the drive over a long period of time.

As a variant of the embodiment, the carrier 44 who have favourited Front Bicycle Sprocket Assembly 35 and the bicycle crank set 27 can be configured as follows.

(A1) In the embodiment, it is exemplified that the bicycle crank set 27 the dust cover 37 includes. The bicycle crank set 27 can without dust cover 37 can be configured.

(A2) In the embodiment, it is exemplified that the first and second axial tooth tip centerline TC1 . TC2 from the first and second axial tooth center plane CA1 . CA2 are offset. If the bicycle crank set 27 the dust cover 37 contains, as in 6B shown, the bicycle crank set 27 (for example the first and second teeth 42a . 42b) be configured that the first and second axial tooth tip centerline TC1 . TC2 not from the first and second axial tooth center plane CA1 . CA2 are offset.

The following directional terms "forward", "backward", "top", "downward", "vertical", "horizontal", "bottom" and "transverse" as well as all other similar directional terms refer to the directions of the wearer 44 , the front bicycle sprocket assembly 35 and the bicycle crank set 27 , Accordingly, as used to describe the present technology, these terms are relative to the wearer 44 , the front bicycle sprocket assembly 35 and the bicycle crank set 27 to interpret.

While only selected embodiments have been selected to illustrate current technology, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made therein without departing from the scope of the technology as defined in the appended claims , For example, the size, shape, position or orientation of the various components can be changed as required.

Components that are directly connected or touching each other can have intermediate structures. The functions of one element can be performed by two and vice versa. The structures and functions of one embodiment can be adopted in another embodiment. It is not necessary that all advantages are present in a particular embodiment at the same time.

Any feature that is unique in the art, alone or in combination with other features, should also be considered by the applicant as a separate description of other technologies, including the structural and / or functional concepts embodied by that feature (s) become.

The above descriptions of the embodiments according to the present technologies are therefore only intended to illustrate and not to limit the technology defined by the appended claims and their equivalents.

LIST OF REFERENCE NUMBERS

1

bicycle

9

bicycle chain

9a

Outer link plate

9b

Inner link plate

9c

Chains roll

11

frame

13

Handle

17

front

17a

front tire

19

rear wheel

19a

rear tire

20

front fork

24

switching device

25

driving part

27

Bike crankset

29

Rear bicycle sprocket assembly

29a

Rear bicycle sprocket

31

rear hub

33

crank assembly

33a

First crank arm

33b

Second crank arm

33c

crankshaft

33d

Second part above

33e

sealing element

35

Front bicycle sprocket assembly

37

dust cover

38

first dust cover

38a

First cavity

40

Second dust cover

40a

Second cavity

40b

Third cavity

41

Front bicycle sprocket

41a

opening

42

sprocket

42a

First tooth

42b

Second tooth

42c

First tooth tip

42e

First radially outermost tooth tip

42f

Second radially outermost tooth tip

43

sprocket

44

carrier

44a

First part above

45

Sprocket mounting portion

45a

plate

45b

wall section

46

Crank assembly mounting portion

47

pivot structure

48

Friction-reducing structure

48a

Ring bearing unit

48a1

inner ring

48a2

outer ring

48a3

Variety of rolling elements

49

Rest structure

49a

First lead

49b

Second lead

49c

connecting element

50

mounting body

51

fastener

52

pivot bearing

52a

First main body

52b

First axle bearing part

52c

Small diameter section

52d

Large diameter section

53

Rotating element

53a

Second main body

53b

Second axle bearing part

54

pivot

AG1, AG2

oblique angle

C1

Rotational center axis

C2

rear axle

C3

central axis

CA1

First axial tooth center plane

CA2

Second axial tooth center plane

CC1

First circumferential tooth center line

CC2

Second circumferential tooth center line

CL

catenary

CP1

First circumferential center

CP2

Second circumferential center

CPa, CPb

Zahnfußpunkt

G1

gap

LCP

Longitudinal center plane

P1

axis of rotation

R1

First radial length

R2

Second radial length

S1

Outer link-axial space

S2

Inner link-axial space

TC1

First axial tooth centerline

TC2

Second axial tooth tip centerline

W1

first chain engaging axial width

W2

second chain engaging axial width

WC1, WC2

Axial width

Claims (23)

A carrier (44) for a bicycle sprocket (41), the carrier (44) comprising: a sprocket attachment portion (45); a crank assembly mounting section (46), the sprocket mounting section (45) and crank assembly mounting section (46) configured to rotate about a central axis of rotation (C1) and torque between the crank assembly mounting section (46) and the Sprocket attachment portion (45) to transmit; a pivot structure (47) having an axis of rotation (P1) disposed a predetermined distance from the center axis of rotation (C1), the sprocket attachment portion (45) and the crank assembly attachment portion (46) configured to rotate around the To rotate the axis of rotation (P1) and the center of rotation (C1); and a dust cover (37) which covers at least the swivel structure (47). Carrier (44) after Claim 1 , wherein the axis of rotation (P1) is not parallel to the central axis of rotation (C1). Carrier (44) after Claim 1 or 2 , further comprising: a friction reducing structure (48) disposed between the swing structure (47) and the sprocket attachment portion (45); the friction reducing structure (48) reduces the friction of the rotational movement between the pivoting structure (47) and the sprocket mounting portion (45); and wherein the dust cover (37) covers the anti-friction structure (48). Carrier (44) after Claim 3 , wherein the friction reducing structure (48) comprises a ring bearing unit (48a) which comprises an inner ring (48a1) and an outer ring (48a2). Carrier (44) after Claim 4 , wherein the inner ring (48a1) of the ring bearing unit (48a) is fixed relative to the swivel structure (47). Carrier (44) after Claim 5 , wherein the swivel structure (47) is a unit separate from the inner ring (48a1) of the ring bearing unit (48a). Carrier (44) after Claim 5 , wherein the pivot structure (47) and the inner ring (48a1) of the ring bearing unit (48a) are formed as an integrally one-piece structure. Carrier (44) according to one of the Claims 1 to 7 , wherein the axis of rotation (P1) is perpendicular to the central axis of rotation (C1). Carrier (44) according to one of the Claims 1 to 8th , wherein the axis of rotation (P1) is further from a rear wheel axis (C2) of a bicycle (1) than the center axis of rotation (C1). Carrier (44) according to one of the Claims 1 to 9 the dust cover (37) covering the crank assembly mounting portion (46). Carrier (44) according to one of the Claims 1 to 10 the dust cover (37) covering the sprocket attachment portion (45). A bicycle sprocket assembly (35) comprising: a sprocket (41) configured to rotate about a central axis of rotation (C1) and having a plurality of sprocket teeth (42) surrounding a circumference of a sprocket body (43) of the sprocket (41 ) are arranged, the plurality of sprocket teeth (42) having at least a first tooth (42a) with a first chain-engaging axial width (W1) with respect to the central axis of rotation (C1) and at least a second tooth (42b) with a second chain-engaging axial width (W2 ) with respect to the central axis of rotation (C1), the first chain-engaging axial width (W1) being greater than the second chain-engaging axial width (W2) in an axial direction with respect to the central axis of rotation (C1); a carrier (44) comprising: a sprocket mounting portion (45); and a crank assembly mounting section (46), wherein the sprocket mounting section (45) and crank assembly mounting section (46) are configured to rotate about the rotational center axis (C1) and torque between the crank assembly mounting section (46) and the sprocket attachment portion (45) to transmit; and a pivot structure (47) having an axis of rotation (P1) disposed a predetermined distance from the center axis of rotation (C1), the sprocket attachment portion (45) and the crank assembly attachment portion (46) configured to rotate around to rotate the axis of rotation (P1) and the center of rotation (C1). Bicycle sprocket assembly (35) after Claim 12 , wherein the first chain engaging axial width (W1) is larger than an inner link axial space (S2) defined between an opposed pair of inner link plates (9b) of a bicycle chain (9) in the axial direction and smaller than an outer link axial space (S1) defined between an opposed pair of outer link plates (9a) of the bicycle chain (9) in the axial direction; and the second chain engaging axial width (W2) is smaller than the inner link axial space (S2). Bicycle sprocket assembly (35) after Claim 12 or 13 , wherein a first radial length (R1) is defined between a first radially outermost tooth tip (42e) of the at least one first tooth (42a) and the central axis of rotation (C1) in the radial direction with respect to the central axis of rotation (C1); a second radial length (R2) is defined between a second radially outermost tooth tip (42f) of the at least one second tooth (42b) and the central axis of rotation (C1) in the radial direction with respect to the central axis of rotation (C1); and the first radial length (R1) is greater than the second radial length (R2). Bicycle sprocket assembly (35) after Claim 13 , wherein the first chain-engaging axial width (W1) of the at least one first tooth (42a) is equal to or greater than 75 percent of the outer link axial space (S1). Bicycle sprocket assembly (35) according to one of the Claims 12 to 15 , wherein the at least one first tooth (42a) has a first axial tooth tip center line (TC1), which is offset from a first axial tooth center plane (CA1) of the at least one first tooth (42a) in the axial direction with respect to the rotational center axis (C1). Bicycle sprocket assembly (35) according to one of the Claims 12 to 16 , wherein the at least one second tooth (42b) has a second axial tooth tip center line (TC2), which is offset from a second axial tooth center plane (CA2) of the at least one second tooth (42b) in the axial direction with respect to the rotational center axis (C1). Bicycle sprocket assembly (35) according to one of the Claims 12 to 17 , wherein the at least one first tooth (42a) is asymmetrical with respect to a circumferential tooth center line (CC1) in a circumferential direction with respect to the center axis of rotation (C1). Bicycle sprocket assembly (35) according to one of the Claims 12 to 17 , wherein the at least one first tooth (42a) is symmetrical with respect to a circumferential tooth center line (CC1) in a circumferential direction with respect to the rotational center axis (C1). Bicycle sprocket assembly (35) according to one of the Claims 12 to 19 , wherein the at least one first tooth (42a) is asymmetrical with respect to a first axial center plane (CA1) in the axial direction with respect to the center axis of rotation (C1). Bicycle sprocket assembly (35) according to one of the Claims 12 to 19 , wherein the at least one first tooth (42a) is symmetrical with respect to a first axial center plane (CA1) in the axial direction with respect to the center axis of rotation (C1). Bicycle sprocket assembly (35) according to one of the Claims 12 to 21 The carrier (44) has a dust cover (37) which covers at least the swivel structure (47). Bicycle crank set (27) comprising: a crank arrangement (33) comprising a first crank arm (33a), a second crank arm (33b) and a crankshaft (33c), which the first crank arm (33a) and the second crank arm (33b) in an assembled state of the crank arrangement (33) links; a bicycle sprocket assembly (35) comprising: a sprocket (41) comprising a plurality of sprocket teeth (42) disposed around a circumference of a sprocket body (43) of the sprocket, the sprocket (41) having an opening (41a) through which the crankshaft (33c) extends extends, wherein the sprocket (41) is configured to rotate about a central axis of rotation (C1); and a carrier (44) with a swivel structure (47) with an axis of rotation (P1) and a dust cover (37) which covers at least the swivel structure (47), the sprocket (41) being rotatable about the center axis of rotation (C1) on the carrier ( 44) is attached so that the sprocket is rotatable about the axis of rotation (P1); and wherein the axis of rotation (P1) is arranged a predetermined distance from the center axis of rotation (C1).

Images