Rear wheel sprocket arrangement

Patent metadata

Field	Value
Publication number	US-10053186-B2
Application number	US-201615085570-A
Country	US
Kind code	B2
Filing date	Mar 30, 2016
Priority date	Mar 30, 2015
Publication date	Aug 21, 2018
Grant date	Aug 21, 2018

Abstract

A plurality of sprockets which are coaxial with respect to a sprocket rotation axis, are arranged with axial spacing from each other and have different numbers of teeth which are constructed for positive-locking engagement with a bicycle chain. The pinion arrangement has a gear range quotient which is formed by division of the number of teeth of the sprocket having the largest diameter by the number of teeth of the sprocket having the smallest diameter, and has a packing density quotient which is formed by division of the number of sprockets in the sprocket arrangement by the axial spacing measured in millimeters of the axially outermost pinions from each other. The pinion arrangement may have a gear range packing coefficient, formed from the product of the gear range quotient and the packing density quotient, which is greater than 1.25.

First claim

The invention claimed is:

1. A bicycle rear wheel sprocket arrangement which can be rotated about a sprocket rotation axis, comprising:
a plurality of sprockets which are coaxial with respect to the sprocket rotation axis and are arranged with axial spacing from each other and have different numbers of teeth which are constructed for positive-locking engagement with a bicycle chain, the plurality of sprockets having:
a gear range quotient which is formed by division of the number of teeth of a sprocket of the plurality of sprockets having the largest diameter by the number of teeth of a sprocket of the plurality of teeth having the smallest diameter, and
a packing density quotient having a value from 0.290 to 0.33, the packing density quotient formed by division of the number of sprockets in the sprocket arrangement by the axial spacing measured in millimeters of the axially outermost sprockets from each other,

wherein the plurality of sprockets has a gear range packing coefficient, formed from the product of the gear range quotient and the packing density quotient, which is greater than 1.25.

2. The bicycle rear wheel sprocket arrangement according to claim 1 , wherein the plurality of sprockets has a gear range packing coefficient, formed from the product of the gear range quotient and the packing density quotient, which is greater than 1.3.

3. The bicycle rear wheel sprocket arrangement according to claim 2 , wherein the plurality of sprockets has a gear range packing coefficient, formed from the product of the gear range quotient and the packing density quotient, which is greater than 1.35.

4. The bicycle rear wheel sprocket arrangement according to claim 3 , wherein the plurality of sprockets has a gear range packing coefficient, formed from the product of the gear range quotient and the packing density quotient, which is greater than 1.4.

5. The bicycle rear wheel sprocket arrangement according to claim 1 , wherein the gear range quotient thereof has a value from 4.2 to 6.

6. The bicycle rear wheel sprocket arrangement according to claim 5 , wherein the gear range quotient thereof has a value from 4.5 to 5.5.

7. The bicycle rear wheel sprocket arrangement according claim 1 , wherein the sprocket having the largest diameter has at least 45 teeth.

8. The bicycle rear wheel sprocket arrangement according claim 7 , wherein the sprocket having the largest diameter has at least 48 teeth.

9. The bicycle rear wheel sprocket arrangement according claim 8 , wherein the sprocket having the largest diameter has at least 50 teeth.

10. The bicycle rear wheel sprocket arrangement according claim 1 , wherein the sprocket having the smallest diameter has at most 12 teeth.

11. The bicycle rear wheel sprocket arrangement according claim 10 , wherein the sprocket having the smallest diameter has at most 11 teeth.

12. The bicycle rear wheel sprocket arrangement according claim 11 , wherein the sprocket having the smallest diameter has at most 10 teeth.

13. The bicycle rear wheel sprocket arrangement according claim 1 , wherein the plurality of sprockets includes at least 8 sprockets.

14. The bicycle rear wheel sprocket arrangement according claim 13 , wherein the plurality of sprockets includes at least 10 sprockets.

15. The bicycle rear wheel sprocket arrangement according claim 14 , wherein the plurality of sprockets includes at least 11 sprockets.

16. The bicycle rear wheel sprocket arrangement according claim 1 , wherein two axially adjacent sprockets are constructed separately from each other and are connected so as to transmit torque and/or an axial force by a plurality of connectors which bridge the axial gap existing between the adjacent sprockets.

17. The bicycle rear wheel sprocket arrangement according claim 16 , wherein the sprocket having the largest diameter and the sprocket which is axially directly adjacent thereto are constructed separately from each other and are connected so as to transmit torque and/or an axial force by a plurality of connection means which bridge the axial gap existing between the adjacent sprockets.

18. The bicycle rear wheel sprocket arrangement according claim 1 , further comprising a bicycle chain, wherein the tooth ring at least of the sprocket having the smallest diameter of the bicycle rear wheel sprocket arrangement is constructed so as to have an axial sprocket thickness which changes, in particular which changes periodically, over a periphery in a peripheral direction between teeth and intermediate tooth spaces which are directly adjacent thereto, wherein the axial thickness of the sprocket is greater in the region of the intermediate tooth spaces than in the region of the teeth.

19. The bicycle rear wheel sprocket arrangement according claim 18 , wherein the tooth ring at least of the sprocket having the smallest diameter of the bicycle rear wheel sprocket arrangement is constructed so as to have an axial sprocket thickness which changes periodically over a periphery in a peripheral direction between teeth and intermediate tooth spaces which are directly adjacent thereto.

20. The bicycle rear wheel sprocket arrangement according claim 18 , wherein the bicycle chain is a roller chain that includes a plurality of rollers which are arranged in an equidistant manner in the longitudinal chain direction with parallel roller rotation axes, which rollers are connected to each other alternately via pairs of parallel inner plates and outer plates, wherein each inner plate is arranged between the roller and an outer plate in the region of a roller connected thereto in the direction of the roller rotation axis, and at least for the sprocket having the smallest diameter, it is the case that the axial width of a roller support face of the sprocket, which support face is constructed for abutting engagement with a roller of the bicycle chain in the region of an intermediate tooth space, deviates from the axial dimension of an outer roller face, in relation to the axial dimension of the outer roller face, constructed for abutment with the roller support face, by no more than 10%.

21. The bicycle rear wheel sprocket arrangement according claim 20 , wherein during a meshing engagement with the at least one sprocket, an inner plate pair has an internal inner plate which is located axially nearer the axial end of the sprocket arrangement with the sprocket having the largest diameter and has an external inner plate which is located axially nearer the axial end of the sprocket arrangement with the sprocket having the smallest diameter, wherein longitudinal center portions of the internal and external inner plate of the inner plate pair are located in the longitudinal chain direction between two rollers which are directly connected to the inner plate pair, wherein an introduction portion of a tooth is introduced between the longitudinal center portions and is withdrawn again during a torque transmission from the bicycle chain to the sprocket which meshes therewith, and for at least one tooth the axial width of the introduction portion of the at least one tooth is smaller than a clear axial width of the longitudinal center portions of the external and internal inner plates from each other so that, during the torque transmission, the end face directed away from the sprocket having the largest diameter in respect of the introduction portion which is introduced between the longitudinal center portions is arranged to be separated by an axial gap from the longitudinal center portion of the external inner plat

Assignees

• Sram De Gmbh

Inventors

• Braedt Henrik
• Reinbold Matthias

Classifications

• B62M9/10 Primary

  involving different-sized wheels, {e.g. rear sprocket chain wheels} selectively engaged by the chain, belt, or the like {(bicycle hubs rotatably arranged on axle B60B27/023)} · CPC title

• B25B27/0071

  for bicycles · CPC title

• B62M9/12 Primary

  the chain, belt, or the like being laterally shiftable {, e.g. using a rear derailleur} · CPC title

• F16H55/30

  Chain-wheels · CPC title