TWI678316B - Pulley assembly for bicycle - Google Patents

Abstract

A bicycle guide wheel set includes: an upper guide wheel having sixteen first teeth on an outer ring edge thereof, and a first groove bottom between any two adjacent first teeth; a lower guide wheel and an outer ring edge thereof It has twenty second teeth, and there is a second groove bottom between any two adjacent second teeth; a connecting member is connected between the upper guide wheel and the lower guide wheel, so that the upper guide wheel and the lower guide wheel are respectively A chain is rotatably provided on the connecting member; a chain is provided on the first and second teeth of the upper guide wheel and the lower guide wheel and is connected to a transmission system, and the chain is located on the upper guide wheel and the The part between the lower guide wheels almost coincides with the inner tangent of the upper guide wheel and the lower guide wheel. When the chain moves in one direction, the upper guide wheel and the lower guide wheel will be driven to rotate in opposite directions; The upper guide wheel has a first circle center, the lower guide wheel has a second circle center, and a length of a center line between the first circle center and the second circle center is defined as L, and each of the first teeth and the first circle center The maximum distance is defined as R1, and the maximum distance between each second tooth and the center of the second circle is defined as R2, and the ratio of L, R1 and R2 is 1: 0.365 ~ 0.38: 0.41 ~ 0. 43.

Description

Bicycle guide wheel set

The invention relates to a guide wheel set of a bicycle.

Press, the bicycle guide wheel system is linked with the transmission system through a chain, thereby providing chain guidance during shifting. The conventional bicycle guide wheel generally has 11 teeth or even less than 11 teeth. The chain rotation angle (the included angle between any two of the three adjacent teeth) is more than 35 degrees, the power inertia is greatly reduced, and the chain meshes with the teeth. The number is small and the chain is easy to be disconnected, but the circumferential angle between the chain and the guide wheel is large, the friction is large, and the energy loss is even greater.

Therefore, how to improve energy transmission efficiency and reduce impairment has become a very important issue.

The main purpose of the present invention is to provide a bicycle guide wheel set, which can reduce the loss, improve the transmission efficiency, and achieve the labor-saving effect, which is beneficial to the riding of road bikes.

To achieve the above object, the present invention provides a bicycle guide wheel set, which includes an upper guide wheel, a lower guide wheel, a connecting member and a chain.

The outer ring edge of the upper guide wheel has sixteen first teeth, and a first groove bottom is provided between any two adjacent first teeth. The outer ring edge of the lower guide wheel has twenty second teeth, any two phases. There is a second groove bottom between adjacent second teeth; the connecting member is connected between the upper guide wheel and the lower guide wheel, so that the upper guide wheel and the lower guide wheel are rotatably provided on the connecting member, respectively. The chain is provided on the first and second teeth of the upper guide wheel and the lower guide wheel and is connected to a transmission system; part of the chain between the upper guide wheel and the lower guide wheel The upper guide wheel coincides with the inner tangent of the lower guide wheel, and when the chain moves in one direction, the upper guide wheel and the lower guide wheel are driven to rotate in opposite directions; wherein the upper guide wheel has a first The center of the circle, the lower guide wheel has a second circle center, the length of the center line between the first circle center and the second circle center is defined as L, and the maximum distance between each first tooth and the first circle center is defined as R1, each The maximum distance between the two teeth and the center of the second circle is defined as R2, and the ratio of L, R1, and R2 is 1: 0.365 to 0.38: 0.41 to 0.43.

Therefore, the bicycle guide wheel set of the present invention can reduce energy loss, improve transmission efficiency, and meet the requirements of road bikes, save labor and increase riding speed.

The following only illustrates the possible implementation aspects of the present invention by way of examples, but is not intended to limit the scope of the present invention to be protected, which will be described first.

1 to 5, the present invention provides a bicycle guide wheel set 10 including an upper guide wheel 11, a lower guide wheel 12, a connecting member 13 and a chain 14 for installation on a bicycle 20. The chain 14 is provided for Connected to a transmission system.

The outer ring edge of the upper guide wheel 11 has sixteen first teeth 111, and a first groove bottom is provided between any two adjacent first teeth 111. The outer ring edge of the lower guide wheel 12 has twenty second teeth. 121, there is a second groove bottom between any two adjacent second teeth 121; the connecting member 14 is connected between the upper guide wheel 11 and the lower guide wheel 12, so that the upper guide wheel 11 and the lower guide wheel 121 The wheels 12 are rotatably provided on the connecting member 14 respectively; the chain 14 is provided on the first guide wheel 111 and the second guide wheel 121 of the lower guide wheel 12 and is connected to a transmission system. The part of the chain 14 located between the upper guide wheel 11 and the lower guide wheel 12 coincides with the inner tangent of the upper guide wheel 11 and the lower guide wheel 12, and when the chain 14 moves in one direction, it will drive the upper The guide wheel 11 and the lower guide wheel 12 rotate in opposite directions; wherein, the upper guide wheel 11 has a first circle center, the lower guide wheel 12 has a second circle center, and the first circle center is connected to the second circle center. The length of the center line is defined as L, the maximum distance between each first tooth 111 and the first circle center is defined as R1, and the maximum distance between each second tooth 121 and the second circle center is defined as R2, and the ratio of L, R1 and R2 for 1: 0.365 ~ 0.38: 0.41 ~ 0.43.

In this embodiment, the acute angle θ1 between the center line of the upper guide wheel 11 and the lower guide wheel 12 and the inner guide line T of the upper guide wheel 11 and the lower guide wheel 12 is between 55 and 58 degrees. The minimum distance between a groove bottom and the first circle center is defined as R3, and the minimum distance between each second groove bottom and the second circle center is defined as R4, and the ratio of L, R3, and R4 is 1: 0.32 to 0.33: 0.375 to 0.385. The central angle θ2 of the outer edge of each of the first teeth 111 with respect to the first center of the circle is 4.7 to 5.7 degrees, and the central angle θ3 of the outer edge of each second tooth 121 with respect to the second center of the circle is 3 to 4 degrees.

In addition, in a preferred embodiment, the first teeth 111 include a first large tooth 1111 with a longer outer edge length and a first small tooth 1112 with a shorter outer edge length. The first large teeth 1111 and the The first small teeth 1112 are alternately arranged. The second teeth 121 include a second large tooth 1211 with a longer outer edge length and a second small tooth 1212 with a shorter outer edge length. The second large teeth 1211 and the The second small teeth 1212 are alternately arranged; more preferably, the distance between each of the first large teeth 1111 to the first circle center is greater than the distance between each of the first small teeth 1112 to the first circle center, and each of the second large teeth 1211 to The distance between the second circle centers is greater than the distance between each second small tooth 1212 and the second circle center.

Therefore, the combination of the relative position and diameter of the guide wheel of the present invention can reduce the power inertia loss and reduce the friction force, and the size of the tooth portion is conducive to grasping the chain and not easy to detach the chain without causing the problem of strenuous riding. Used for bicycles with road speed requirements such as road bikes.

10‧‧‧Bicycle guide wheel set

11‧‧‧ Upper guide wheel

111‧‧‧first tooth

1111‧‧‧The first big tooth

1112‧‧‧The first small tooth

12‧‧‧ lower guide wheel

121‧‧‧ second tooth

1211‧‧‧The second largest tooth

1212‧‧‧Second small tooth

13‧‧‧Connector

14‧‧‧Chain

20‧‧‧ Bicycle

L‧‧‧ Length of the center line between the first center and the second center

T‧‧‧ Inside tangent of upper and lower guide wheels

R1‧‧‧ the maximum distance between the first tooth and the first circle center

R2‧‧‧Maximum distance between the second tooth and the center of the second circle

R3‧‧‧The minimum distance between the bottom of the first groove and the center of the first circle

R4‧‧‧The minimum distance between the bottom of the second groove and the center of the second circle

θ1‧‧‧ acute angle

θ2‧‧‧ center angle

θ3‧‧‧ center angle

Fig. 1 is a perspective view of the present invention. FIG. 2 is an exploded perspective view of the present invention. Figure 3 is a front view of the present invention. Fig. 4 is a rear view of the present invention. Figure 5 is a schematic diagram of the use of the present invention.

Claims (5)

A bicycle guide wheel set includes: an upper guide wheel, the outer ring of which has sixteen first teeth, and a first groove bottom between any two adjacent first teeth; the lower guide wheel, the The outer periphery of the lower guide wheel has twenty second teeth, and a second groove bottom is provided between any two adjacent second teeth; a connecting member is connected between the upper guide wheel and the lower guide wheel, so that The upper guide wheel and the lower guide wheel are respectively rotatably provided on the connecting member; a chain is provided on the first and second teeth of the upper guide wheel and the lower guide wheel and is connected to a transmission system , The part of the chain between the upper guide wheel and the lower guide wheel almost coincides with the inner tangent of the upper guide wheel and the lower guide wheel, and when the chain moves in one direction, the upper guide wheel and the The lower guide wheel rotates in the opposite direction; wherein, the upper guide wheel has a first circle center, the lower guide wheel has a second circle center, and the length of the center line between the first circle center and the second circle center is defined as L, each The maximum distance between the first tooth and the first circle center is defined as R1, and the maximum distance between each second tooth and the second circle center is defined as R2, and the distance between L, R1, and R2 The ratio is 1: 0.365 ~ 0.38: 0.41 ~ 0.43; wherein the first teeth include the first large teeth with a longer outer edge length and the first small teeth with a shorter outer edge length, and the first large teeth and the The first small teeth are alternately arranged, the second teeth include a second large tooth with a longer outer edge length and a second small tooth with a shorter outer edge length, the second large teeth alternate with the second small teeth arrangement. The bicycle guide wheel set according to claim 1, wherein an acute angle between a concentric line of the upper guide wheel and the lower guide wheel and an inner tangent of the upper guide wheel and the lower guide wheel is between 55 and 58 degrees. The bicycle guide wheel set according to claim 1, wherein a minimum distance between each first groove bottom and the first circle center is defined as R3, and a minimum distance between each second groove bottom and the second circle center is defined as R4, L The ratio of R3 and R4 is 1: 0.32 ~ 0.33: 0.375 ~ 0.385. The bicycle wheel set according to claim 1, wherein the center angle of the outer edge of each of the first teeth with respect to the first center is 4.7 to 5.7 degrees, and the center of the outer edge of each of the second teeth with respect to the center of the second center The angle is 3 to 4 degrees. The bicycle guide wheel set according to claim 1, wherein a distance between each of the first large teeth and the first circle center is greater than a distance between each of the first small teeth and the first circle center and each of the second large teeth to the The distance between the two circle centers is greater than the distance between each second small tooth and the second circle center.