TWM605748U - Gearshift mechanism of bicycle - Google Patents

Abstract

This creation is a bicycle transmission mechanism, which is set at the position of the power shaft. The transmission mechanism mainly includes: a first sprocket, a second sprocket, an external sprocket set, a first driving chain and a second driving chain, the first sprocket And the second sprocket are respectively arranged on the power shaft, the first sprocket is provided with a first tooth portion and a first driving sprocket is provided on the outer side, and the second sprocket is provided with a second tooth portion and a second driving sprocket is provided on the outer side, wherein The second tooth portion is highly adjacent to the first tooth portion, and the outer sprocket set is located away from the first and second sprocket positions. It includes a first variable speed sprocket and a second variable speed sprocket. The first driving chain is meshed with the first sprocket. A driving sprocket and the first variable speed sprocket, the second driving chain is engaged with the second driving sprocket and the second variable speed sprocket, the first sprocket and the second sprocket can be operated at different speeds by the above-mentioned transmission mechanism To achieve the purpose of changing the reduction ratio.

Description

Gearshift mechanism of bicycle

This creation is a gear shifting device, especially a bicycle gear shifting mechanism.

According to the traditional bicycle, the sprocket with the front position of the pedal in the pedal position has a structure with different numbers of teeth in order to change the speed. Therefore, the sprocket will have a size difference. If you want to achieve a larger deceleration, the largest chain There will be a large drop between the wheel and the smallest sprocket, which makes it difficult for the chain to climb.

Take the three common sprocket sizes as an example. The number of teeth in the sprocket size from large to small is 50 teeth, 39 teeth and 30 teeth. The maximum reduction ratio of this combination is 30/50=0.6. 39/50=0.78, and it will be reduced again to reach the final reduction ratio of 0.6.

In order to simplify and smooth the chain speed change process and take into account the reduction ratio at the same time, different tooth number combinations have been developed. When the sprocket has two sizes as an example, the tooth number combination can be 34/50=0.68 or 36/52=0.69 In terms of the 34/50 combination, the outer diameter of the 50t sprocket is 208mm, and the outer diameter of the 34t sprocket is 144mm, (208-144)/2=32mm. When shifting, the derailleur must allow the chain to climb by friction The distance of 32mm is already the current limit, so it is impossible to have a lower reduction ratio to facilitate climbing.

In order to achieve the tighter gear ratio, the gears on the rear wheels can currently be configured to 11 groups, and the sprocket on the pedals is lowered in the direction of 50 teeth. When it reaches 34 teeth, the circumferential size of the inner and outer discs is already very different. , Climbing is not easy, but the matched gear ratio will still have multiple sets of repeated gear changes, and it is impossible to reach a gear ratio close to or less than 1.

The detailed features and advantages of this creation are described in detail in the implementation mode below, and the content is sufficient to enable anyone who is familiar with relevant skills to understand the technical content of this creation and implement it according to this description. Anyone familiar with the relevant skills can easily understand the purpose and advantages of this creation with the contents, scope of patent application and schema disclosed in the book.

The main purpose of this creation is to use the first sprocket, the second sprocket, the external sprocket set, the first driving chain and the second driving chain in the speed change mechanism, so that the first sprocket and the second sprocket can be different The purpose of changing the reduction ratio is achieved at the speed, and the second sprocket can be slightly larger or slightly smaller than or equal to the size of the first sprocket, so that the main drive chain will be smoother when changing the first sprocket or the second sprocket. , And solve the problem of difficult climbing in the past.

In order to achieve the above-mentioned purpose, the present invention is a bicycle gear shifting mechanism, which is arranged at the position of a power shaft of a bicycle. The gear shifting mechanism includes: a first sprocket fixed to the power shaft and provided with a first tooth portion, A first driving sprocket is provided on the outer side of the first sprocket; a second sprocket is pivoted on the power shaft and provided with a second tooth portion, and a second driving sprocket is provided on the outer side of the second sprocket, Wherein the second tooth portion is highly adjacent to the first tooth portion; an external sprocket set is arranged at a position away from the first sprocket and the second sprocket, the external sprocket set includes: a first variable speed sprocket And a second variable speed sprocket connected to the first variable speed sprocket; a first driving chain meshed with the first driving sprocket and the first variable speed sprocket; and a second driving chain meshed with the The second driving sprocket and the second variable speed sprocket.

According to an embodiment of the present invention, a space is defined between the first sprocket and the second sprocket.

According to an embodiment of the invention, the external sprocket set is installed on the bicycle.

According to an embodiment of the invention, it further includes a bracket erected at the power shaft position and located in the space, and one end of the bracket is provided for the external sprocket set.

According to an embodiment of the invention, a derailleur is further included, which is arranged on the bicycle and close to the side of the first sprocket.

According to an embodiment of the present invention, it further includes a main drive chain, which passes through the derailleur and selectively links the first tooth portion or the second tooth portion by the derailleur.

According to an embodiment of the present invention, the first gear sprocket and the second gear sprocket have the same or different numbers of teeth.

1: bicycle

10: Power shaft

12: Rear wheel

14: chainring

2: Transmission mechanism

20: The first sprocket

200: first tooth

201: The first drive sprocket

21: second sprocket

210: second tooth

212: The second drive sprocket

22: External sprocket set

220: First gear sprocket

222: second gear sprocket

23: The first drive chain

24: The second drive chain

25: space

3: bracket

4: derailleur

5: The main drive chain

Figure 1 is a three-dimensional schematic diagram of a preferred embodiment of creation.

Figure 2 is a three-dimensional exploded schematic diagram of a preferred embodiment of creation.

Figure 3 is another perspective exploded schematic diagram of the preferred embodiment of the creation.

Fig. 4 is a schematic diagram of the use state of the deceleration operation of the preferred embodiment of the creation.

Figure 5 is a schematic diagram of the structure of the second embodiment of the creation.

Fig. 6 is a perspective exploded view of Fig. 5.

FIG. 7 is another perspective exploded schematic view of FIG. 5.

Figure 8 is a schematic diagram of the use state of Figure 5 decelerating operation.

The following specific examples illustrate the implementation of this creation, and those familiar with this technique can easily understand the other advantages and effects of this creation from the content disclosed in this manual.

The structure, ratio, size, etc. shown in the drawings in this manual are only used to match the content disclosed in the manual for the understanding and reading of those who are familiar with the art, and are not used to limit the implementation of this creation. Conditions, so it does not have any technical significance. Any modification of the structure, changes in proportions, or adjustments in size, without affecting the effects and goals that can be achieved by this creation, should remain in this creation. The technical content disclosed must be within the scope. At the same time, terms such as "one", "two", "shang", etc. cited in this manual are only for ease of description. It is not used to limit the scope of implementation of this creation, and the change or adjustment of its relative relationship shall be regarded as the scope of implementation of this creation without substantial changes to the technical content.

Please refer to FIG. 1, FIG. 2 and FIG. 3, which are a three-dimensional schematic diagram, a three-dimensional exploded schematic diagram, and a three-dimensional exploded schematic diagram of a preferred embodiment of the creation. This creation is a bicycle transmission mechanism, which is set at the position of the power shaft 10 of the bicycle 1. The transmission mechanism 2 mainly includes: a first sprocket 20, a second sprocket 21, an external sprocket set 22, a first driving chain 23, and a second sprocket Two driving chains 24, the first sprocket 20 and the second sprocket 21 are respectively arranged on the power shaft 10, wherein the first sprocket 20 has a first tooth portion 200 and a first driving sprocket 201 is provided on the outside, and the second sprocket 21 has a second tooth portion 210 and a second driving sprocket 212 is arranged on the outside, wherein the second tooth portion 210 is highly adjacent to the first tooth portion 200, and the outer sprocket group 22 is arranged away from the first sprocket 20 and the second sprocket 21 position, where the outer sprocket set 22 includes a first variable speed sprocket 220 and a second variable speed sprocket 222 connected to the first variable speed sprocket 220. The first driving chain 23 is engaged with the first driving sprocket 201 and the first variable speed sprocket 201 The sprocket 220 and the second driving chain 24 are engaged with the second driving sprocket 212 and the second speed changing sprocket 222.

A space 25 is defined between the first sprocket 20 and the second sprocket 21 described above, and the outer sprocket set 22 is installed on the bicycle 1.

Also refer to FIG. 4, which is a schematic diagram of the use state of the decelerating operation of the preferred embodiment of this creation. Taking deceleration as an example, according to the operation mode of the above structure, after introducing a specific number of teeth, it will be clearer how to achieve the purpose of deceleration through the above-mentioned speed change mechanism 2. In this embodiment, the external sprocket 22 is mainly arranged on the bicycle 1, and the external sprocket The position of the group 22 is between the front wheels and the rear wheels. The first gear sprocket 220 and the second gear sprocket 222 included in the outer sprocket group 22 are an integral structure, that is, they rotate synchronously. When the first tooth 200 in the first sprocket 20 and the second tooth 210 in the second sprocket 21 are set to 22 teeth, the first sprocket 20 fixed on the power shaft 10 is driven by the first outside The sprocket 201 is set to 11 teeth, and the first variable speed sprocket 220 and the second variable speed sprocket 222 in the external sprocket set 22 are both set to 11 The second driving sprocket 212 pivotally connected to the second sprocket 21 on the power shaft 10 is set to 22 teeth.

After the number of teeth is set, the main driving chain 5 engages the first sprocket 20 and the chainring 14 (single-sprocket or multi-sprocket) located on the rear wheel 12 of the bicycle 1, and the main driving chain 5 passes through the derailleur 4 , The derailleur 4 is mainly arranged on the bicycle 1 and close to the side of the first sprocket 20, so the derailleur 4 can select the main drive chain 5 to link the first tooth 200 or the second sprocket 21 of the first sprocket 20 The second tooth 210. Then, when the main driving chain 5 is driven by the first sprocket 20, in addition to driving the rear wheel 12 to rotate, the rotation of the first sprocket 20 causes the first driving sprocket 201 to rotate synchronously, and the first driving chain 23 Linked with the first variable speed sprocket 220, since the second variable speed sprocket 222 and the first variable speed sprocket 220 are an integral structure, the second variable speed sprocket 222 will rotate synchronously. At this time, the second drive chain 24 is engaged with the second variable speed The sprocket 222 and the second driving sprocket 212 are therefore linked to enable the second sprocket 21 to be driven. Due to the various tooth configurations mentioned above, the derailleur 4 can be used (in order to avoid excessive lines covering the actuation method, the diagram The derailleur 4 is omitted in 4. Please refer to Figure 1 to Figure 3 for the position of the derailleur 4) Change the main drive chain 5 to select the normal speed (linked to the first sprocket 20) or the decelerated speed (linked to The second sprocket 21). It can be seen from the above that the first sprocket 20 with this number of teeth makes one revolution, and the second sprocket 21 makes half a revolution, thereby achieving the purpose of deceleration.

If the deceleration effect needs to be more obvious, the first driving sprocket 201 on the outer side of the first sprocket 20 can be maintained at 11 teeth, and the number of teeth of the first variable speed sprocket 220 in the outer sprocket set 22 can be changed to 19 teeth. The second variable speed sprocket 222 is maintained with 11 teeth, and the second driving sprocket 212 pivotally connected to the second sprocket 21 on the power shaft 10 is changed to 19 teeth. In this way, the aforementioned deceleration effect can be achieved. More obvious.

Referring to FIG. 5, FIG. 6 and FIG. 7 together, it is a schematic structural diagram of the second embodiment of the creation, a three-dimensional exploded diagram of FIG. 5, and a three-dimensional exploded diagram of FIG. 5 from another angle. The speed change mechanism 2 in this embodiment mainly includes: a first sprocket 20, a second sprocket 21, an external sprocket set 22, a first driving chain 23 and a second driving chain 24, mainly in the first sprocket 20 and the second sprocket Space 25 between two sprockets 21 There is a bracket 3, one end of the bracket 3 is erected at the position of the power shaft 10, and the other end is provided with an external sprocket set 22 and away from the space 25, wherein the positions of the first driving sprocket 201 and the second driving sprocket 212 are not located in the space 25, respectively , That is, the first driving sprocket 201 is arranged outside the first sprocket 20, and the second driving sprocket 212 is arranged outside the second sprocket 21.

Refer to FIG. 8 together, which is a schematic diagram of the use state of the deceleration operation in FIG. 5. Taking deceleration as an example, according to the above-mentioned structural operation mode, after introducing a specific number of teeth, it is clearer how to achieve deceleration through the above-mentioned speed change mechanism 2. In this embodiment, the external sprocket 22 is mainly arranged in the bracket 3, and the bracket 3 is located in the first The position of the space 25 between the sprocket 20 and the second sprocket 21, wherein the position of the outer sprocket set 22 is between the front wheel and the rear wheel, and the outer sprocket set 22 includes the first speed sprocket 220 and the second speed change The sprocket 222 is an integral structure, that is, it rotates synchronously. When the first tooth 200 in the first sprocket 20 and the second tooth 210 in the second sprocket 21 are set to 22 teeth, the first sprocket 20 fixed on the power shaft 10 is driven by the first outside The sprocket 201 is set to 11 teeth, and the first variable speed sprocket 220 and the second variable speed sprocket 222 in the external sprocket set 22 are both set to 11 teeth, and the second sprocket is pivotally connected to the power shaft 10 The second driving sprocket 212 on the outside of 21 is set to 22 teeth.

After the number of teeth is set, the main driving chain 5 engages the first sprocket 20 and the chainring 14 (single-sprocket or multi-sprocket) located on the rear wheel 12 of the bicycle 1, and the main driving chain 5 passes through the derailleur 4 , The derailleur 4 is mainly arranged on the bicycle 1 and close to the side of the first sprocket 20, so the derailleur 4 can select the main drive chain 5 to link the first tooth 200 or the second sprocket 21 of the first sprocket 20 The second tooth 210. Then, when the main driving chain 5 is driven by the first sprocket 20, in addition to driving the rear wheel 12 to rotate, the rotation of the first sprocket 20 causes the first driving sprocket 201 to rotate synchronously, and the first driving chain 23 Linked with the first variable speed sprocket 220, since the second variable speed sprocket 222 and the first variable speed sprocket 220 are an integral structure, the second variable speed sprocket 222 will rotate synchronously. At this time, the second drive chain 24 is engaged with the second variable speed The sprocket 222 and the second driving sprocket 212 are therefore linked to allow the second sprocket 21 to be driven, due to the various teeth mentioned above Therefore, it is possible to change the main drive chain 5 to select the general speed through the derailleur 4 (to avoid excessive lines covering the actuation method, the derailleur 4 is omitted in Figure 8. For the position of the derailleur 4, please refer to Figures 5 to 7). Linked to the first sprocket 20) or decelerated speed (linked to the second sprocket 21). It can be seen from the above that the first sprocket 20 with this number of teeth makes one revolution, and the second sprocket 21 makes half a revolution, thereby achieving the purpose of deceleration.

If the deceleration effect needs to be more obvious, the first driving sprocket 201 on the outer side of the first sprocket 20 can be maintained at 11 teeth, and the number of teeth of the first variable speed sprocket 220 in the outer sprocket set 22 can be changed to 19 teeth. The second variable speed sprocket 222 is maintained with 11 teeth, and the second driving sprocket 212 pivotally connected to the second sprocket 21 on the power shaft 10 is changed to 19 teeth. In this way, the aforementioned deceleration effect can be achieved. More obvious.

It can be seen from the above embodiments that the number of teeth of the first driving sprocket 201, the first speed changing sprocket 220, the second driving sprocket 212, and the second speed changing sprocket 222 can be adjusted to adjust the second sprocket 21 Different rotation speeds, in addition, the derailleur 4 and the main driving chain 5 seen in the various embodiments, the derailleur 4 is arranged on the bicycle 1 and close to the side of the first sprocket 20, and the main driving chain 5 passes through the derailleur The first tooth part 200 or the second tooth part 210 is selected by the derailleur 4. Since the number and size of the first sprocket 20 and the second sprocket 21 are approximately the same, and they are arranged side by side, the chain is mainly driven 5. When changing the first sprocket 20 or the second sprocket 21, it will be smoother, and there will be no problem of difficult climbing. The size of the second sprocket 21 can be slightly larger or slightly smaller than or equal to the first sprocket 20, and varies mainly according to different purposes.

The above-mentioned embodiments are only illustrative of the principle and effect of the creation, and are not used to limit the creation. Anyone familiar with this technique can modify the above-mentioned embodiment without departing from the spirit and scope of this creation. Therefore, the scope of protection of the rights of this creation should be listed in the scope of patent application described later.

1: bicycle

10: Power shaft

2: Transmission mechanism

20: The first sprocket

200: first tooth

201: The first drive sprocket

22: External sprocket set

220: First gear sprocket

222: second gear sprocket

23: The first drive chain

4: The second drive chain 2

25: space

4: derailleur

5: The main drive chain

Claims (7)

A speed change mechanism for a bicycle, which is arranged at a position of a power shaft of a bicycle, the speed change mechanism includes: A first sprocket, which is fixed to the power shaft and is provided with a first tooth portion, and a first driving sprocket is arranged outside the first sprocket; A second sprocket, which is pivoted on the power shaft and provided with a second tooth part, a second driving sprocket is arranged outside the second sprocket, wherein the second tooth part is highly adjacent to the first tooth part; An external sprocket set located far away from the first sprocket and the second sprocket, the external sprocket set includes: a first variable speed sprocket and a second variable chain connected to the first variable speed sprocket wheel; A first driving chain that meshes with the first driving sprocket and the first speed change sprocket; and A second driving chain is engaged with the second driving sprocket and the second speed change sprocket. The transmission mechanism of a bicycle according to claim 1, wherein a space is defined between the first sprocket and the second sprocket. The transmission mechanism of a bicycle according to claim 1, wherein the external sprocket set is mounted on the bicycle. The speed change mechanism of a bicycle according to claim 2, further comprising a bracket erected at the power shaft position and located in the space, and one end of the bracket is provided for the external sprocket set. The speed change mechanism of a bicycle according to claim 1, further comprising a derailleur, which is arranged on the bicycle and close to the side of the first sprocket. The speed change mechanism of a bicycle as described in claim 5, further includes a main drive chain, which passes through the derailleur and is selectively linked to the first tooth part or the second tooth part by the derailleur. The speed change mechanism of a bicycle according to claim 1, wherein the first speed change sprocket and the second speed change sprocket have the same or different numbers of teeth.

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