TW202210359A - Bicycle speed change mechanism enabling the first sprocket and the second sprocket to achieve the objective of changing deceleration or acceleration ratio at different rotational speeds - Google Patents

Abstract

This invention relates to a bicycle speed change mechanism which is disposed to the position of the power axle. The speed change mechanism mainly comprises 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 disposed to the power axle. The first sprocket has a first tooth part and a first driving sprocket disposed to one side thereof. The second sprocket has a second tooth part and a second driving sprocket disposed to one side thereof. The second tooth part is adjacent to the first tooth part in height. The external sprocket set comprises a first speed change sprocket and a second speed change sprocket connected to the first speed change sprocket. The first driving chain is meshed with the first driving sprocket and the first speed change sprocket. The second driving chain is meshed with the second driving sprocket and the second speed change sprocket. By the aforementioned speed change mechanism, the first sprocket and the second sprocket are enabled to achieve the objective of changing deceleration or acceleration ratio at different rotational speeds.

Description

bicycle shifting mechanism

The invention relates to a speed change mechanism, especially a bicycle speed change mechanism.

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

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

In order to simplify and smooth the chain shifting process, and at the same time take into account the reduction ratio, different combinations of tooth numbers have been developed. When the sprocket is taken as an example of two sizes, the combination of the number of teeth can be a combination of 34/50=0.68 or 36/52=0.69 , For the combination of 34/50, the outer diameter of the 50t sprocket is 208mm, the outer diameter of the 34t chain wheel is 144mm, (208-144)/2=32mm, when shifting, the derailleur needs to let the chain 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.

The detailed features and advantages of the present invention are described in detail in the following embodiments, and the content is sufficient to enable any person skilled in the relevant art to understand the technical content of the present invention and implement it accordingly, and according to the content disclosed in this specification, the scope of the patent application and the drawings , any person skilled in the related art can easily understand the related objects and advantages of the present invention.

The main purpose of the present invention is to use the first sprocket, the second sprocket, the outer 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 in different At the same time, the second sprocket can be slightly larger or slightly smaller or equal to the size of the first sprocket, so that the main drive chain can be changed when the first sprocket or the second sprocket is changed. It will be smoother and solve the problem of difficult climbing in the past.

In order to achieve the above object, the present invention relates to a bicycle speed change mechanism, which is arranged at the position of a power shaft. The speed change mechanism includes: a first sprocket fixed on the power shaft and provided with a first tooth portion, the first sprocket. A first driving sprocket is set on one side of the sprocket; a second sprocket is pivoted on the power shaft and has a second tooth portion, and a second driving sprocket is set on one side of the second sprocket, wherein The second tooth portion is highly adjacent to the first tooth portion; an outer sprocket set includes a first speed change sprocket and a second speed change sprocket connected to the first speed change sprocket; a first drive chain, which meshing with the first driving sprocket and the first speed change sprocket; and a second driving chain meshing with the second driving sprocket and the second speed change 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 present invention, it further includes a bracket erected at the position of the power shaft and located in the space, and one end of the bracket is provided for the external sprocket set to be arranged.

According to an embodiment of the present invention, one end of the bracket is far away from the space.

According to an embodiment of the present invention, one end of the bracket is located at the space.

According to an embodiment of the present invention, the positions of the first driving sprocket and the second driving sprocket are respectively located in the space and adjacent to the outer sprocket set.

According to an embodiment of the present invention, the outer sprocket set is mounted on the bicycle and located between the front wheel and the rear wheel.

According to an embodiment of the present invention, the positions of the first driving sprocket and the second driving sprocket are not located in the space, respectively, and are far away from the outer sprocket set.

According to an embodiment of the present invention, it further includes a derailleur, which is disposed on a side of the bicycle close to the first sprocket.

According to an embodiment of the present invention, it further includes a main driving chain which is passed through the derailleur and selectively linked by the derailleur to the first tooth portion or the second tooth portion.

1: Bicycle

10: Power shaft

12: rear wheel

14: Chainring

2: Transmission mechanism

20: First sprocket

200: First tooth

201: The first drive sprocket

21: Second sprocket

210:Second tooth

212: The second driving sprocket

22: External sprocket set

220: 1st shift 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

FIG. 1 is a three-dimensional schematic diagram of a preferred embodiment of the present invention.

2 is a schematic exploded perspective view of a preferred embodiment of the present invention.

FIG. 3 is another perspective exploded schematic diagram of the preferred embodiment of the present invention.

FIG. 4 is a schematic diagram of the use state of the deceleration operation according to the preferred embodiment of the present invention.

FIG. 5 is a schematic structural diagram of a second embodiment of the present invention.

FIG. 6 is a schematic exploded perspective view of FIG. 5 .

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

FIG. 8 is a schematic diagram of the use state of the deceleration operation of FIG. 5 .

FIG. 9 is a schematic structural diagram of a third embodiment of the present invention.

FIG. 10 is a schematic exploded perspective view of FIG. 8 .

FIG. 11 is another perspective exploded schematic view of FIG. 8 .

FIG. 12 is a schematic diagram of the use state of the speed-increasing operation of FIG. 8 .

The embodiments of the present invention are described below by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

The structures, proportions, sizes, etc. shown in the drawings in this specification are only used to cooperate with the contents disclosed in the specification for the understanding and reading of those who are familiar with the art, and are not intended to limit the implementation of the present invention. Therefore, it has no technical significance, and any modification of the structure, the change of the proportional relationship or the adjustment of the size should still fall within the scope of the present invention without affecting the effect that the present invention can produce and the purpose that can be achieved. The disclosed technical content must be within the scope of coverage. At the same time, terms such as "one", "two", "on", etc. quoted in this specification are only for the convenience of description, and are not used to limit the scope of the present invention. Changes in their relative relationships or Adjustments, if there is no substantial change in the technical content, should also be regarded as the scope of the present invention.

Please refer to FIG. 1 , FIG. 2 and FIG. 3 , which are a three-dimensional schematic view, a three-dimensional exploded schematic view, and a three-dimensional exploded schematic view of a preferred embodiment of the present invention. The present invention is a bicycle speed change mechanism, which is arranged at the position of the power shaft 10 of the bicycle 1. The speed change mechanism 2 mainly includes: a first sprocket 20, a second sprocket 21, an external sprocket set 22, a first driving chain 23 and a first sprocket. Two driving chains 24, the first sprocket 20 and the second chain 21 are respectively disposed on the power shaft 10, wherein the first sprocket 20 has a first tooth portion 200 and a first driving sprocket 201 is disposed on one side, and the second chain The wheel 21 has a second tooth portion 210 and a second driving sprocket 212 on one side, wherein the second tooth portion 210 is highly adjacent to the first tooth portion 200 , and the outer sprocket set 22 includes a first speed change sprocket 220 and a connecting A second speed change sprocket 222 of a speed change sprocket 220, the first drive chain 23 is engaged with the first drive sprocket 201 and the first speed change sprocket 220, and the second drive chain 24 is engaged with the second drive sprocket 212 and the second drive sprocket 220. Shift sprocket 222 .

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

Referring to FIG. 4 together, it is a schematic diagram of the use state of the deceleration operation according to the preferred embodiment of the present invention. Taking deceleration as an example, according to the above structure and operation mode, it is clearer how to achieve the purpose of deceleration through the above-mentioned speed change mechanism 2 after the specific number of teeth is introduced. On the bicycle 1, the position of the external sprocket set 22 is between the front wheel and the rear wheel, wherein the first speed change sprocket 220 and the second speed change sprocket 222 included in the external sprocket set 22 Synchronized rotation. When the first tooth part 200 of the first sprocket 20 and the second tooth part 210 of the second sprocket 21 are set to 22 teeth, the first sprocket 20 fixed on the power shaft 10 is driven by the first drive on the outside. The sprocket 201 is set to 11 teeth, while the first speed change sprocket 220 and the second speed change sprocket 222 in the outer sprocket set 22 are both set to 11 teeth, and the second sprocket pivoted on the power shaft 10 The second driving sprocket 212 on the outer side of 21 is set to 22 teeth.

After the setting of each tooth number is completed, the main driving chain 5 meshes with the first sprocket 20 and the toothed plate 14 (single toothed plate or multi toothed plate) located on the rear wheel 12 of the bicycle 1. At the same time, the main driving chain 5 passes through the derailleur 4. , the derailleur 4 is mainly arranged on the bicycle 1 and is close to the side of the first sprocket 20 , so the main drive chain 5 can be selected by the derailleur 4 to link the first tooth part 200 or the second sprocket 21 of the first sprocket 20 the second tooth portion 210 . Then, when the main drive 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 drive sprocket 201 to rotate synchronously, and the first drive chain 23 The first speed change sprocket 220 is linked together. Since the second speed change sprocket 222 and the first speed change sprocket 220 are integrally formed, the second speed change sprocket 222 will rotate synchronously. At this time, the second drive chain 24 is engaged with the second speed change gear. The sprocket 222 and the second driving sprocket 212 are interlocked and the second sprocket 21 is driven. Due to the above-mentioned various tooth configurations, the derailleur 4 can pass through the derailleur 4. The derailleur 4 is omitted in 4. Please refer to Figures 1 to 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 The second sprocket 21). As can be seen from the above, the first sprocket 20 with this number of teeth rotates once, and the second sprocket 21 rotates half a circle, 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 speed change sprocket 220 in the outer sprocket set 22 can be changed to 19 teeth, The second speed change sprocket 222 is maintained at 11 teeth, and the second driving sprocket 212 on the outer side of the second sprocket 21 pivotally connected to 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 diagram of the structure of the second embodiment of the present invention, an exploded perspective view of FIG. 5 , and another perspective exploded perspective view of FIG. 5 . The speed change mechanism 2 in this embodiment mainly includes: a first sprocket 20 , a second sprocket 21 , an outer sprocket set 22 , a first driving chain 23 and a second driving chain 24 . A bracket 3 is arranged at the space 25 between the two sprockets 21 . One end of the bracket 3 is erected at the position of the power shaft 10 , and the other end of the bracket 3 is provided with an external sprocket group 22 away from the space 25 . The first driving sprocket 201 and the second driving chain The positions of the wheels 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 .

Referring to FIG. 8 together, it is a schematic diagram of the use state of the deceleration operation in FIG. 5 . Taking deceleration as an example, according to the above structure and operation mode, it is clearer how to achieve deceleration through the above-mentioned speed change mechanism 2 after the specific number of teeth is introduced. 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, wherein the first speed change sprocket 220 and the second speed change included in the outer sprocket set 22 The sprocket 222 is a one-piece structure, that is, it rotates synchronously. When the first tooth part 200 of the first sprocket 20 and the second tooth part 210 of the second sprocket 21 are set to 22 teeth, the first sprocket 20 fixed on the power shaft 10 is driven by the first drive on the outside. The sprocket 201 is set to 11 teeth, while the first speed change sprocket 220 and the second speed change sprocket 222 in the outer sprocket set 22 are both set to 11 teeth, and the second sprocket pivoted on the power shaft 10 The second driving sprocket 212 on the outer side of 21 is set to 22 teeth.

After the setting of each tooth number is completed, the main driving chain 5 meshes with the first sprocket 20 and the toothed plate 14 (single toothed plate or multi toothed plate) located on the rear wheel 12 of the bicycle 1. At the same time, the main driving chain 5 passes through the derailleur 4. , the derailleur 4 is mainly arranged on the side of the bicycle 1 and close to the first sprocket 20, so the derailleur 4 can select the main drive The chain 5 links the first tooth portion 200 of the first sprocket 20 or the second tooth portion 210 of the second sprocket 21 . Then, when the main drive 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 drive sprocket 201 to rotate synchronously, and the first drive chain 23 The first speed change sprocket 220 is linked together. Since the second speed change sprocket 222 and the first speed change sprocket 220 are integrally formed, the second speed change sprocket 222 will rotate synchronously. At this time, the second drive chain 24 is engaged with the second speed change gear. The sprocket 222 and the second driving sprocket 212 are interlocked and the second sprocket 21 is driven. Due to the above-mentioned various tooth configurations, the derailleur 4 can pass through the derailleur 4. 8, the derailleur 4 is omitted, please refer to Figure 5 to Figure 7 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 speed that has been decelerated (linked to The second sprocket 21). It can be seen from the above that the first sprocket 20 with this number of teeth rotates once, and the second sprocket 21 rotates half a circle, 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 speed change sprocket 220 in the outer sprocket set 22 can be changed to 19 teeth, The second speed change sprocket 222 is maintained at 11 teeth, and the second driving sprocket 212 on the outer side of the second sprocket 21 pivotally connected to the power shaft 10 is changed to 19 teeth. In this way, the aforementioned deceleration effect can be achieved. more obvious.

Referring to FIG. 9 , FIG. 10 and FIG. 11 together, it is a schematic structural diagram of a third embodiment of the present invention and a three-dimensional exploded schematic diagram of FIG. 8 . The speed change mechanism 2 mainly includes: a first sprocket 20 , a second sprocket 21 , an outer sprocket group 22 , a first driving chain 23 and a second driving chain 24 , mainly between the first chain wheel 20 and the second chain wheel 21 . A bracket 3 is arranged at the space 25 of the 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 group 22 and is located at the space 25, where the first driving sprocket 201 and the second driving sprocket 212 are arranged at the positions They are respectively located between the spaces 25, that is, the first driving sprocket 201 is located inside the first sprocket 20, and the second driving sprocket 212 is located inside the second sprocket 21, so the first driving sprocket 201 and the second driving chain Wheels 212 are arranged accordingly. It can be understood from the above structure that the first driving sprocket 201 , the second driving sprocket 212 , the outer sprocket group 22 , the first driving chain 23 , the second driving chain 24 and the bracket 3 are all arranged on the first chain The space 25 between the wheel 20 and the second sprocket 21 , that is, no speed change structure can be seen from the appearance of the first sprocket 20 and the second sprocket 21 .

Referring to FIG. 12 together, it is a schematic diagram of the use state of the speed-up operation in FIG. 8 . Taking the speed increase as an example, according to the above structure and operation mode, after introducing the specific number of teeth, it can be more clear how to achieve the speed increase through the above-mentioned speed change mechanism 2. When the first tooth part 200 of the first sprocket 20 and the second sprocket 21 When the second tooth portion 210 in the middle is set to 22 teeth, the first driving sprocket 201 on the inner side of the first sprocket 20 fixed on the power shaft 10 is set to 10 teeth. When the first speed change sprocket 220 on the same side of the driving sprocket 201 is set to 14 teeth, and the second driving sprocket 212 pivotally connected to the inner side of the second sprocket 21 on the power shaft 10 is set to 14 teeth, at the same time The second speed change sprocket 222 on the same side as the second driving sprocket 212 in the outer sprocket set 22 is set to 10 teeth.

After the setting of each tooth number is completed, the main driving chain 5 meshes with the first sprocket 20 and the toothed plate 14 (single toothed plate or multi toothed plate) located on the rear wheel 12 of the bicycle 1. At the same time, the main driving chain 5 passes through the derailleur 4. , the derailleur 4 is mainly arranged on the bicycle 1 and is close to the side of the first sprocket 20 , so the main drive chain 5 can be selected by the derailleur 4 to link the first tooth part 200 or the second sprocket 21 of the first sprocket 20 the second tooth portion 210 . Then, when the main drive 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 drive sprocket 201 to rotate synchronously, and the first drive chain 23 The first speed change sprocket 220 is linked together. Since the second speed change sprocket 222 and the first speed change sprocket 220 are integrally formed, the second speed change sprocket 222 will rotate synchronously. At this time, the second drive chain 24 is engaged with the second speed change gear. The sprocket 222 and the second driving sprocket 212 are interlocked and the second sprocket 21 is driven. Due to the above-mentioned various tooth configurations, the derailleur 4 can pass through the derailleur 4. The derailleur 4 is omitted in 12. Please refer to Figure 9 to Figure 11 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 speed that has been increased (linked on the second sprocket 21). It can be seen from the above that the arrangement of the number of teeth can increase the rotational speed of the second sprocket 21 by about 2 times, thereby achieving the purpose of speeding up.

If the rotation speed of the second sprocket 21 needs to be increased again, the first driving sprocket 201 on the inner side of the first sprocket 20 fixed on the power shaft 10 can be set to 19 teeth. When the first speed change sprocket 220 on the same side of the driving sprocket 201 is set to 11 teeth, and the second driving sprocket 212 pivotally connected to the inner side of the second sprocket 21 on the power shaft 10 is set to 11 teeth, Meanwhile, the second speed change sprocket 222 on the same side as the second drive sprocket 212 in the outer sprocket set 22 is set to 19 teeth, wherein the first drive sprocket 201 , the first speed change sprocket 220 , the second drive sprocket 212 and the The gear size configuration of the second speed change sprocket 222 is mainly that the lengths of both sides of the first driving chain 23 and the second driving chain 24 will be equal, not one long and the other short, which is relatively simple. The rotation speed of the second sprocket 21 is adjusted by changing the number of teeth of the first driving sprocket 201 , the first shifting sprocket 220 , the second driving sprocket 212 and the second shifting sprocket 222 .

It can be seen from the above-mentioned embodiments that by adjusting the number of teeth of the first driving sprocket 201 , the first shifting sprocket 220 , the second driving sprocket 212 and the second shifting sprocket 222 , the second sprocket 21 can be adjusted to have a certain number of teeth. Different rotation speeds, in addition, from the derailleur 4 and the main driving chain 5 visible in each embodiment, the derailleur 4 is arranged on the side of the bicycle 1 and is close to the first sprocket 20, and the main driving chain 5 is passed through the derailleur. The first sprocket 200 or the second sprocket 210 is selected and linked by the derailleur 4, because the number and size of the first sprocket 20 and the second sprocket 21 are approximately the same, and they are side by side, so the main drive chain 5. It will be smoother when changing the first sprocket 20 or the second sprocket 21, and there will be no problem of difficulty in climbing. The size of the second sprocket 21 may be slightly larger or slightly smaller or equal to the size of the first sprocket 20 , which may vary depending on the purpose.

The above-mentioned embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Any person skilled in the art can make modifications to the above-described embodiments without departing from the spirit and scope of the present invention. Therefore, the scope of the right protection of the present invention should be listed in the scope of the patent application described later.

1: Bicycle

10: Power shaft

2: Transmission mechanism

20: First sprocket

200: First tooth

201: The first drive sprocket

22: External sprocket set

220: 1st shift sprocket

222: Second gear sprocket

23: The first drive chain

24: The second drive chain

25: Space

4: Derailleur

5: The main drive chain

Claims (10)

A bicycle shifting mechanism, which is arranged at the position of the power shaft of the bicycle, the shifting mechanism comprises: a first sprocket, which is fixed on the power shaft and has a first tooth portion, and a first driving sprocket is arranged on one side of the first sprocket; a second sprocket pivoted on the power shaft and provided with a second tooth portion, a second driving sprocket is disposed on one side of the second sprocket, wherein the height of the second tooth portion is adjacent to the first tooth portion ; an outer sprocket set, which includes a first shift sprocket and a second shift sprocket connected to the first shift sprocket; a first drive chain engaged with the first drive sprocket and the first speed change sprocket; and A second driving chain is engaged with the second driving sprocket and the second speed changing sprocket. The bicycle shifting mechanism of claim 1, wherein a space is defined between the first sprocket and the second sprocket. The bicycle shifting mechanism as claimed in claim 2, further comprising a bracket arranged at the position of the power shaft and located in the space, and one end of the bracket is provided for the external sprocket set to be arranged. The bicycle shifting mechanism as claimed in claim 3, wherein the other end of the bracket is away from the space. The bicycle shifting mechanism according to claim 3, wherein the other end of the bracket is located at the space. The bicycle shifting mechanism according to claim 5, wherein the positions of the first driving sprocket and the second driving sprocket are respectively located in the space and adjacent to the outer sprocket set. The bicycle shifting mechanism of claim 2, wherein the outer sprocket set is mounted on the bicycle. The bicycle shifting mechanism as claimed in claim 7, wherein the positions of the first driving sprocket and the second driving sprocket are not located in the space, respectively, and are far away from the outer sprocket set. The bicycle shifting mechanism according to claim 1, further comprising a derailleur, which is disposed on the bicycle and close to the side of the first sprocket. The bicycle shifting mechanism as claimed in claim 9, further comprising a main driving chain, which is passed through the derailleur and selectively linked to the first tooth portion or the second tooth portion by the derailleur.

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