TWI891270B - Bicycle sprocket structure - Google Patents

Abstract

A bicycle sprocket structure comprises: a sprocket body rotatable about a rotational axis driven thereby; the sprocket body having, along an axial direction of the rotational axis, first and second sides respectively having a first side face and a second side face, the first side face being closer to an adjacent smaller sprocket body than the second side face; a plurality of engaging teeth provided on an outer peripheral surface of the sprocket body for engagement with a chain; a shifting promoting portion provided on the sprocket body for promoting the chain to shift from the sprocket body to the adjacent smaller sprocket body; the shifting promoting portion having a first shifting promoting tooth and a second shifting promoting tooth; the first shifting promoting tooth having a first shifting promoting recess formed in the first side face of the sprocket body and recessed toward the second side face; the second shifting promoting tooth being adjacent to the first shifting promoting tooth in a circumferential direction and having no other tooth between, and the second shifting promoting tooth having a second shifting promoting recess formed in the first side face of the sprocket body and recessed toward the second side face.

Description

Bicycle gear structure

The present invention relates to bicycles, and in particular to a bicycle gear structure.

Current bicycles can be changed using gears of varying sizes. This essentially involves combining front and rear derailleurs with gears of varying sizes to alter the chain's transmission ratio between the gears. This design allows riders to adjust pedal speed to suit varying speeds and terrain.

Generally speaking, one of the most common gear shifting methods is through a rear derailleur and cassette. A bicycle's rear wheel is typically equipped with multiple rear sprockets, each with a varying number of teeth, and a rear derailleur located on the rear frame. The rear derailleur changes the size of the rear sprockets connected by the chain. While the front sprockets remain unchanged, larger rear sprockets provide a lower gear ratio, making it easier to climb hills. Smaller rear sprockets provide a higher gear ratio, suitable for fast, flat roads.

However, problems often arise when the chain moves across the rear sprockets. For example, when shifting from a larger sprocket to a smaller one, the sprocket structure can cause the chain to take some time to shift from one sprocket to the next. This can cause the bike to feel noticeably choppy during shifts, affecting the rider's riding experience. This is especially noticeable when performing multiple gear changes in a row.

The primary purpose of this invention is to provide a bicycle gear structure that can effectively improve the stability of upshifting operations and reduce the jerky feel produced during upshifting.

To achieve the above-mentioned purpose, the present invention provides a bicycle gear structure, comprising: a gear body, which can be driven to rotate along a rotating axis; the gear body has a first side surface and a second side surface respectively on two opposite sides of the rotating axis, the first side surface being adjacent to a smaller gear body than the second side surface; a plurality of engaging teeth, which are provided on the outer peripheral surface of the gear body, for providing a The chain engages; an upshift promoting portion is provided on the gear body to promote the chain to upshift from the gear body to the adjacent smaller gear body; the upshift promoting portion has a first upshift promoting tooth and a second upshift promoting tooth; the first upshift promoting tooth has a first upshift recess formed on the first side of the gear body and recessed in the direction toward the second side; the second upshift promoting tooth is circumferentially The second upshift promoting tooth is upwardly adjacent to the first upshift promoting tooth and has no other tooth therebetween, and the second upshift promoting tooth has a second upshift recess formed on the first side of the gear plate body and recessed in a direction toward the second side; and an upshift inhibiting portion is provided on the gear plate body and adjacent to the upshift promoting portion, for inhibiting the chain from upshifting from the gear plate body to another adjacent smaller gear plate body; the upshift inhibiting portion has An upshift inhibiting tooth is circumferentially adjacent to a side of the second upshift promoting tooth opposite to the first upshift promoting tooth, with no other tooth between the upshift inhibiting tooth and the second upshift promoting tooth; wherein the first upshift promoting tooth and the second upshift promoting tooth are offset toward the second side; and the upshift inhibiting tooth is offset toward the first side relative to the first upshift promoting tooth and the second upshift promoting tooth.

In one embodiment, the gear plate body defines a centerline along an axial width perpendicular to the rotational axis; the top portion of the first upshift facilitating tooth has a first tooth top surface; the first tooth top surface forms an angle with the centerline that is not equal to 0, such that the distance between an end of the first upshift facilitating tooth distal to the second upshift facilitating tooth and the first side surface is greater than the distance between an end of the first upshift facilitating tooth proximal to the second upshift facilitating tooth and the first side surface.

In one embodiment, the top of the second upshift promoting tooth has a second tooth top surface; the second tooth top surface forms an angle with the centerline that is not equal to 0, so that the distance between the end of the second upshift promoting tooth closer to the first upshift promoting tooth and the first side surface is greater than the distance between the end of the second upshift promoting tooth farther from the first upshift promoting tooth and the first side surface.

In one embodiment, the first upshift recess has a first side concave surface and a first bottom concave surface, the first side concave surface being connected to the first bottom concave surface; the second upshift recess has a second side concave surface and a second bottom concave surface, the second side concave surface being connected to the second bottom concave surface; wherein the first side concave surface is separated from the second side concave surface.

In one embodiment, the first concave surface of the first upshift recess forms an angle with the first side surface that is not equal to 0; the second concave surface of the second upshift recess is substantially parallel to the first side surface, such that the first concave surface is inclined relative to the second concave surface.

In one embodiment, the width of the first bottom concave surface gradually decreases from an end away from the second upshift facilitating tooth toward an end closer to the second upshift facilitating tooth, such that the tooth root width of the first upshift facilitating tooth along an axial width direction parallel to the rotation axis gradually increases from an end away from the second upshift facilitating tooth toward an end closer to the second upshift facilitating tooth.

In one embodiment, the upshift inhibiting portion further includes an upshift limiting tooth circumferentially adjacent to a side of the first upshift promoting tooth opposite the second upshift promoting tooth, with no other tooth between the upshift limiting tooth and the first upshift promoting tooth. The upshift limiting tooth has a limiting recess formed on the second side of the gear plate body and recessed toward the first side, thereby causing the upshift limiting tooth to deflect toward the first side.

In one embodiment, the root width of the upshift limiting tooth along an axial width direction parallel to the rotation axis is smaller than the root width of the engaging tooth along the axial width direction parallel to the rotation axis.

In one embodiment, the second upshift facilitating gear further includes a third upshift recess formed on the first side of the gear plate body and recessed toward the second side; wherein the third upshift recess is located on a side of the second upshift recess opposite to the first upshift recess and communicates with the second upshift recess.

In one embodiment, the third upshift recess is a C-shaped recess with an upward notch, having a third side concave surface and a third bottom concave surface. The third side concave surface is generally parallel to the first side surface, and the third bottom concave surface is connected to the third side concave surface and inclined relative to the first side surface. The third side concave surface of the third upshift recess is separated from the second side concave surface of the second upshift recess.

The following is a detailed description of the preferred embodiments of the present invention based on its purpose, efficacy, and structural configuration, along with accompanying drawings.

10: Base

12: Teeth clenching

14: First side

16: Second side

20: Upshift Promotion Department

30: First upshift boost gear

32: Top of first tooth

34: First upshift recess

340: First side concave surface

342: First bottom concave surface

36: First chamfered surface

40: Second upshift boost gear

42: Top of the second tooth

44: Second upshift recess

440: Second side concave surface

442: Second bottom concave surface

46: Third upshift recess

460: Third side concave surface

462: Third bottom concave surface

48: Second chamfered surface

50: Upshift suppression unit

52: Upshift inhibitor gear

54: Upshift limiter gear

540: Limit the recess

542: Restricted side concave surface

544: Restricted bottom concave surface

60: Upshift Promotion Department

70: First upshift boost gear

72: First upshift recess

720: First side concave surface

722: First bottom concave surface

80: Second upshift boost gear

82: Second upshift recess

820: Second side concave surface

822: Second bottom concave surface

84: Third upshift recess

840: Third side concave surface

842: Third bottom concave surface

90: Upshift inhibitor gear

A: Rotation axis

B: Centerline

S: Bicycle gear set

S1: Gear plate body

S2: Gear Plate Body

S3: Gear Plate Body

S4: Gear Plate Body

S5: Gear Plate

S6: Gear Plate

S7: Gear Plate Body

S8: Gear Plate Body

S9: Gear Plate

S10: Gear Plate

S11: Gear Plate

Figure 1 is a front view of a bicycle gear assembly according to a preferred embodiment of the present invention.

Figure 2 is a right side view of a bicycle gear assembly according to a preferred embodiment of the present invention.

Figure 3 is a front view of the larger gear plate body of a preferred embodiment of the present invention.

Figure 4 is a partially enlarged front view of Figure 3.

Figure 5 is a partially enlarged 3D image of Figure 3.

Figure 6 is a partially enlarged top view of Figure 3.

Figure 7 is a rear view of the larger gear plate body of a preferred embodiment of the present invention.

Figure 8 is a partial enlarged rear view of Figure 7.

Figure 9 is a partially enlarged 3D image of Figure 7.

Figure 10 is a front view of the smaller gear plate body of a preferred embodiment of the present invention.

Figure 11 is a partial enlarged front view of Figure 10.

Figure 12 is a partially enlarged 3D image of Figure 10.

The following description, with reference to the accompanying drawings, is of preferred embodiments of the present invention. It should be understood that these drawings and descriptions are for illustrative purposes only and are not intended to limit the present invention. Furthermore, terms such as "upper" and "lower," "left" and "right," "front" and "rear," "first" and "second," etc., are used to clearly illustrate the relative positions of components or mechanisms and are not intended to be limiting.

Referring to Figures 1 and 2 , a preferred embodiment of the present invention provides a bicycle gear assembly S, which is a rear gear configuration and includes a plurality of gear bodies S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, and S11. The gear bodies S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, and S11 are of varying sizes and are arranged side by side from largest to smallest along an axial direction of a rotation axis A. Adjacent gear bodies S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, and S11 are spaced at least a predetermined distance apart. The gear bodies S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, and S11 are engaged by a chain (not shown). An upshift can be accomplished by controlling a rear derailleur (not shown) to drive the chain in an upshift direction L1 from a larger gear body to an adjacent smaller gear body. Alternatively, a downshift can be accomplished by controlling the rear derailleur to drive the chain in a downshift direction L2 from a smaller gear body to an adjacent larger gear body. The structure and operation of the rear derailleur and chain are known techniques and are not the core content of this invention. Their details will not be described here.

In this embodiment, since the larger, equally toothed disc bodies have substantially similar structures, the description herein will be based on one of the disc bodies, S11. The structures of the remaining disc bodies can be readily extrapolated. Referring to Figures 3 through 6, the disc body S11 comprises an annular base 10 and a plurality of engaging teeth 12. These engaging teeth 12 extend radially outward from the base 10 and are arranged in an annular pattern around the disc body S11 to engage the chain. The disc body S11 has a first side surface 14 and a second side surface 16 on opposite sides along the axial direction, respectively. The first side 14 faces the adjacent smaller gear body S10, while the second side 16 faces away from the adjacent smaller gear body S10. The gear body S11 has at least one upshift-promoting portion 20 near its circumferential edge. For example, in this embodiment, the gear body S11 has three upshift-promoting portions 20. Each upshift-promoting portion 20 facilitates the upshifting of the chain from the larger gear body S11 to the adjacent smaller gear body S10.

Specifically, the upshift facilitating portions 20 include a first upshift facilitating tooth 30 and a second upshift facilitating tooth 40. The first upshift facilitating tooth 30 and the second upshift facilitating tooth 40 are adjacent to each other, with no other tooth interposed therebetween. As shown in FIG6 , the gear plate body S11 has a virtual centerline B extending along the axial width of the rotation axis A. This centerline B is located directly between the first side surface 14 and the second side surface 16. The top portion of the first upshift facilitating tooth 30 includes a first tooth top surface 32. The first tooth top surface 32 extends in a direction that forms an angle with the centerline B that is not equal to zero. This ensures that the distance between the end of the first upshift facilitating tooth 30 farther from the second upshift facilitating tooth 40 and the first side surface 14 is greater than the distance between the end of the first upshift facilitating tooth 30 closer to the second upshift facilitating tooth 40 and the first side surface 14. Consequently, the first upshift facilitating tooth 30 is arranged obliquely relative to the engaging tooth 12. The first tooth top surface 32 of the first upshift facilitating tooth 30 is offset relative to the centerline B toward the second side surface 16. The second upshift facilitating tooth 40 has a second tooth top surface 42 at its top. The second tooth top surface 42 extends in a direction that forms an angle with the centerline B that is not equal to zero. This ensures that the distance between the end of the second upshift facilitating tooth 40 closest to the first upshift facilitating tooth 30 and the first side surface 14 is greater than the distance between the end of the second upshift facilitating tooth 40 further from the first upshift facilitating tooth 30 and the first side surface 14. Consequently, the second upshift facilitating tooth 40 is arranged obliquely relative to the engaging tooth 12. Furthermore, the second tooth top surface 42 of the second upshift facilitating tooth 40 is offset relative to the centerline B toward the second side surface 16. This makes it easier for the chain to complete the upshifting action from the first upshift facilitating tooth 30 or the second upshift facilitating tooth 40.

Referring again to Figures 3 through 5 , the first upshift facilitating gear 30 has a first upshift recess 34 formed on the first side 14 of the gear body S11 and recessed toward the second side 16. This recess serves to reduce interference between the gear body S11 and the chain during upshifting from the gear body S11 to the adjacent, smaller gear body S10. Specifically, the first upshift recess 34 has a first side concave surface 340 and a first bottom concave surface 342. The first side concave surface 340 is connected to the first bottom concave surface 342, and the first bottom concave surface 342 is farther from the first tooth top surface 32 of the first upshift facilitating tooth 30 than the first side concave surface 340. The first side concave surface 340 and the first side surface 14 form an angle that is not equal to 0, and the first bottom concave surface 342 is inclined relative to the first side surface 14. The width of the first bottom concave surface 342 along the axial width direction parallel to the rotation axis A gradually decreases from the end distal to the second upshift facilitating tooth 40 toward the end proximal to the second upshift facilitating tooth 40, causing the tooth root width of the first upshift facilitating tooth 30 along the axial width direction parallel to the rotation axis A to gradually increase from the end distal to the second upshift facilitating tooth 40 toward the end proximal to the second upshift facilitating tooth 40. Consequently, the first side concave surface 340 also tilts from the end distal to the second upshift facilitating tooth 40 toward the end proximal to the second upshift facilitating tooth 40. Furthermore, the first upshift facilitating tooth 30 further includes a first chamfered surface 36. The first chamfered surface 36 is connected to the first side concave surface 340 and the first tooth top surface 32, respectively, and is inclined relative to the first tooth top surface 32.

The second upshift facilitating gear 40 has a second upshift recess 44 and a third upshift recess 46. The second upshift recess 44 and the third upshift recess 46 are interconnected and formed on the first side surface 14 of the gear body S11, recessed toward the second side surface 16. The second upshift recess 44 and the third upshift recess 46 are used to reduce interference between the gear body S11 and the chain during upshifting from the gear body S11 to the adjacent, smaller gear body S10. Specifically, the second upshift recess 44 has a second side concave surface 440 and a second bottom concave surface 442. The second side concave surface 440 is connected to the second bottom concave surface 442, and the second bottom concave surface 442 is farther from the second tooth top surface 42 than the second side concave surface 440. The second side concave surface 440 is generally parallel to the first side surface 14, and the second bottom concave surface 442 is inclined relative to the first side surface 14. The third upshift recess 46 has a third side concave surface 460 and a third bottom concave surface 462. The third side concave surface 460 is connected to the third bottom concave surface 462 and the second side concave surface 440, and the third bottom concave surface 462 is farther from the second tooth top surface 42 of the second upshift facilitating tooth 40 than the third side concave surface 460 and connected to the second bottom concave surface 442. The third side concave surface 460 is generally parallel to the first side surface 14, while the third bottom concave surface 462 is inclined relative to the first side surface 14. This allows the chain to be guided by the second side concave surface 440 and the second bottom concave surface 442 of the second upshift recess 44, or the third side concave surface 460 and the third bottom concave surface 462 of the third upshift recess 46, to the adjacent smaller gear plate body S10. Furthermore, the second upshift facilitating tooth 40 has a second chamfered surface 48. This second chamfered surface 48 is connected to the second side concave surface 440 and the second tooth top surface 42, respectively, and is inclined relative to the second tooth top surface 42.

The first upshift recess 34 is separated from the second upshift recess 44. Specifically, the first side concave surface 340 of the first upshift recess 34 is separated from the second side concave surface 440 of the second upshift recess 44, and the first bottom concave surface 342 of the first upshift recess 34 is separated from the second bottom concave surface 442 of the second upshift recess 44. The first side concave surface 340 of the first upshift recess 34 is an inclined surface relative to the first side surface 14, while the second side concave surface 440 of the second upshift recess 44 is a flat surface relative to the first side surface 14. This can also be referred to as the first side concave surface 340 of the first upshift recess 34 being inclined relative to the second side concave surface 440 of the second upshift recess 44.

According to the above structure, the bicycle gear structure of the present invention has two upshift modes. The first upshift mode is that when the chain moves to the position of the first upshift facilitating tooth 30 of the gear body S11, the rear shifter is controlled to shift the chain so that the chain enters the second upshift recess 44 along the first upshift recess 34 of the first upshift facilitating tooth 30, and then moves to the adjacent smaller gear body S10 to complete the upshift action. The second upshift mode is when the chain moves to the position of the second upshift promoting tooth 40 of the gear body S11, the rear transmission is controlled to move the chain so that the chain enters the third upshift recess 46 along the second upshift recess 44 and then moves to the adjacent smaller gear body S10 to complete the upshift action. Whether in the first or second upshift mode, the structure of the first upshift-promoting tooth 30 and the second upshift-promoting tooth 40 of the upshift-promoting portion 20 facilitates the chain's upshift from the gear plate body S11 to the adjacent, smaller gear plate body S10, effectively reducing the jerky feel caused by interference and time difference between the chain and the gear plate body S11 during the upshift process.

In addition to the upshift facilitating portion 20, the present invention also includes a corresponding upshift inhibiting portion 50 in an area adjacent to each upshift facilitating portion 20 on the gear plate body S11. For example, in this embodiment, there are three upshift inhibiting portions 50. Each upshift inhibiting portion 50 includes an upshift inhibiting tooth 52. The upshift inhibiting tooth 52 and the second upshift facilitating tooth 40 are adjacent to each other, with no other tooth intervening. Consequently, the second upshift facilitating tooth 40 is located between the first upshift facilitating tooth 30 and the upshift inhibiting tooth 52. The upshift inhibiting tooth 52 is offset relative to the first and second upshift facilitating teeth 30, 40, toward the first side surface 14. The upshift inhibiting tooth 52 is used to inhibit the chain from performing an upshift operation. When the chain moves to the upshift inhibiting tooth 52, the upshift inhibiting tooth 52 is offset toward the first side 14. Therefore, the majority of the chain falls behind the upshift inhibiting tooth 52 and cannot be shifted by the rear derailleur. Consequently, the chain cannot perform an upshift until it reaches the next set of upshift facilitating sections 20. Therefore, the upshift inhibiting tooth 52 restricts the chain to upshifting only at the upshift facilitating sections 20.

As shown in Figures 7 to 9, the upshift inhibiting portion 50 further includes two upshift limiting teeth 54, which are adjacent to each other without another tooth between them. The two upshift limiting teeth 54 are located on one side of the first upshift promoting tooth 30 opposite the second upshift promoting tooth 40. Each of the two upshift limiting teeth 54 has a limiting recess 540. The two limiting recesses 540 are formed on the second side surface 16 and are recessed toward the first side surface 14. The limiting recess 540 has a connected limiting side concave surface 542 and a limiting bottom concave surface 544. In this embodiment, the limiting side concave surface 542 is generally parallel to the second side surface 16, and the limiting bottom concave surface 544 is inclined relative to the second side surface 16. In another embodiment, the limiting concave surface and the second side surface form an angle not equal to 0, such that the limiting concave surface is inclined relative to the second side surface. Due to the concave structure of the two limiting recesses 540, the root width of the two upshift limiting teeth 54 along the axial width direction parallel to the rotation axis A is smaller than the root width of the other engaging teeth 12 along the axial width direction parallel to the rotation axis A, and the two upshift limiting teeth 54 are offset relative to the centerline B toward the first side surface 14 (as shown in FIG. 6 ). Thus, when the chain is positioned at the second upshift limiting teeth 54, a portion of the chain abuts against the two limiting recesses 540, preventing the chain from performing an upshift beyond the second upshift limiting teeth 54. In other words, the two upshift limiting teeth 54 and the upshift inhibiting tooth 52, positioned one behind the other in the circumferential direction, restrict the chain from performing an upshift until it reaches the upshift facilitating portion 20.

It is particularly important to note that the upshift facilitation portion of the present invention can be configured with different structural configurations on the larger and smaller gears. Figures 10 through 12 illustrate the structure of the gear body S6 in this embodiment, and the structure of the smaller gear body can be readily applied. The structure of the gear body S6 is similar to that of the larger gear body S11, so its details are omitted. The gear body S6 also has an upshift facilitation portion 60, which includes a first upshift facilitation tooth 70 and a second upshift facilitation tooth 80. The first upshift facilitating tooth 70 has a first upshift recess 72 having a first side concave surface 720 and a first bottom concave surface 722. The second upshift facilitating tooth 80 has a second upshift recess 82 and a third upshift recess 84. The second upshift recess 82 has a second side concave surface 820 and a second bottom concave surface 822. The third upshift recess 84 has a third side concave surface 840 and a third bottom concave surface 842. Unlike the larger gear body S11, the first concave bottom surface 722 of the first upshift recess 72 of the gear body S6 is connected to the second concave bottom surface 822 of the second upshift recess 82, and the second concave bottom surface 822 of the second upshift recess 82 is connected to the third concave bottom surface 842 of the third upshift recess 84. The third upshift recess 84 is a C-shaped groove with an upward notch, formed between the second upshift facilitating tooth 80 and an upshift inhibiting tooth 90 of the gear body S6. The third side concave surface 840 of the third upshift recess 84 is separated from the second side concave surface 820 of the second upshift recess 82.

In summary, the bicycle gear structure of the present invention provides two upshifting modes. The first and second upshift-promoting teeth of the upshift-promoting portion facilitate upshifting from the chain to the adjacent, smaller gear, thereby reducing the choppy feel caused by interference between the chain and the gear during upshifting. Furthermore, the bicycle gear structure of the present invention restricts upshifting to the chain only when it is in the upshift-promoting portion through the rear upshift-inhibiting teeth and front upshift-limiting teeth of the upshift-inhibiting portion, effectively improving smooth upshifting.

The above embodiments are merely illustrative of the technology and efficacy of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify and alter the above embodiments without departing from the technical principles and spirit of the present invention. Therefore, the scope of protection of the present invention shall be as described in the patent application below.

10: Base

12: Teeth clenching

14: First side

20: Upshift Promotion Department

30: First upshift boost gear

40: Second upshift boost gear

52: Upshift inhibitor gear

54: Upshift limiter gear

S11: Gear Plate

Claims (10)

A bicycle gear structure comprises: A gear body capable of being driven to rotate along a rotation axis; the gear body having a first side surface and a second side surface on opposite sides of the rotation axis, respectively, the first side surface being adjacent to a smaller portion of the gear body than the second side surface; A plurality of engaging teeth disposed on an outer circumference of the gear body for engaging a chain; An upshift facilitating portion is provided on the gear body to facilitate upshifting of the chain from the gear body to the adjacent smaller gear body; the upshift facilitating portion comprises a first upshift facilitating tooth and a second upshift facilitating tooth; the first upshift facilitating tooth comprises a first upshift recess formed on the first side of the gear body and recessed in a direction toward the second side; the second upshift facilitating tooth is circumferentially adjacent to the first upshift facilitating tooth with no other tooth therebetween, and the second upshift facilitating tooth comprises a second upshift recess formed on the first side of the gear body and recessed in a direction toward the second side; and An upshift inhibiting portion is disposed on the gear plate body and adjacent to the upshift facilitating portion, and is configured to inhibit the chain from upshifting from the gear plate body to the adjacent smaller gear plate body. The upshift inhibiting portion includes an upshift inhibiting tooth circumferentially adjacent to a side of the second upshift facilitating tooth opposite the first upshift facilitating tooth, with no other tooth between the upshift inhibiting tooth and the second upshift facilitating tooth. The first upshift facilitating tooth and the second upshift facilitating tooth are offset toward the second side. The upshift inhibiting tooth is offset relative to the first upshift facilitating tooth and the second upshift facilitating tooth toward the first side. A bicycle gear structure as described in claim 1, wherein the gear body defines a centerline along an axial width direction perpendicular to the rotation axis; the top of the first upshift promoting tooth has a first tooth top surface; the first tooth top surface and the centerline form an angle that is not equal to 0, so that the distance between the end of the first upshift promoting tooth away from the second upshift promoting tooth and the first side surface is greater than the distance between the end of the first upshift promoting tooth close to the second upshift promoting tooth and the first side surface. A bicycle gear structure as described in claim 2, wherein the top of the second upshift promoting tooth has a second tooth top surface; the second tooth top surface forms an angle with the center line that is not equal to 0, so that the distance between one end of the second upshift promoting tooth close to the first upshift promoting tooth and the first side surface is greater than the distance between one end of the second upshift promoting tooth far from the first upshift promoting tooth and the first side surface. A bicycle gear structure as described in claim 1, wherein the first shift-up recess has a first side concave surface and a first bottom concave surface, the first side concave surface is connected to the first bottom concave surface; the second shift-up recess has a second side concave surface and a second bottom concave surface, the second side concave surface is connected to the second bottom concave surface; wherein the first side concave surface is separated from the second side concave surface. The bicycle gear structure as described in claim 4, wherein the first side concave surface of the first shift-up recess forms an angle with the first side surface that is not equal to 0; the second side concave surface of the second shift-up recess is generally parallel to the first side surface, so that the first side concave surface is inclined relative to the second side concave surface. A bicycle gear structure as described in claim 4, wherein the width of the first bottom concave surface gradually decreases from one end away from the second upshift promoting tooth toward one end close to the second upshift promoting tooth, so that the root width of the first upshift promoting tooth along an axial width direction parallel to the rotation axis gradually increases from one end away from the second upshift promoting tooth toward one end close to the second upshift promoting tooth. A bicycle gear structure as described in claim 1, wherein the upshift inhibition portion further includes an upshift limiting tooth, which is adjacent to one side of the first upshift promoting tooth opposite to the second upshift promoting tooth in the circumferential direction, and there is no other tooth between the upshift limiting tooth and the first upshift promoting tooth; the upshift limiting tooth has a limiting recess formed on the second side of the gear plate body and recessed in the direction toward the first side, so that the upshift limiting tooth is offset in the direction toward the first side. A bicycle gear structure as described in claim 7, wherein the root width of the upshift limiting tooth in an axial width direction parallel to the rotation axis is smaller than the root width of the engaging tooth in the axial width direction parallel to the rotation axis. A bicycle gear structure as described in claim 4, wherein the second upshift promoting gear further includes a third upshift recess formed on the first side of the gear body and recessed in a direction toward the second side; wherein the third upshift recess is located on a side of the second upshift recess opposite to the first upshift recess and is connected to the second upshift recess. A bicycle gear structure as described in claim 9, wherein the third upshift recess is a C-shaped groove with a notch facing upward, having a third side concave surface and a third bottom concave surface; the third side concave surface is generally parallel to the first side surface, the third bottom concave surface is connected to the third side concave surface and inclined relative to the first side surface, and the third side concave surface of the third upshift recess is separated from the second side concave surface of the second upshift recess.