TWI846167B - Bicycle rear cassette - Google Patents

Abstract

A bicycle rear cassette is configured to be mounted on a bicycle wheel hub The bicycle rear cassette includes a largest sprocket, a first gasket, a first sprocket and a plurality of fasteners. A tooth amount of the largest sprocket is equal to or larger than 40. The first gasket is connected to the largest sprocket. The first gasket has a plurality of first through holes. The first gasket is located between the first sprocket and the largest sprocket, and the first sprocket has a plurality of engagement teeth and a plurality of first mount holes, the engagement teeth are configured to be directly mounted on the bicycle wheel hub. The fastener are respectively disposed through the first through holes of the first gasket and the first mount holes of the first sprocket so as to fasten the largest sprocket, a first gasket and the first sprocket with each other.

Description

Bicycle rear flywheel

The present invention relates to a rear flywheel, in particular a bicycle rear flywheel.

The bicycle market has been booming in recent years. Whether it is high-end racing bicycles or mass-market bicycles used as a means of transportation and leisure, they are all popular among consumers, prompting manufacturers to pay more attention to users' needs for bicycle functions and continuously improve and enhance the body materials and equipment functions.

In the current bicycle rear flywheel, the sprockets with larger outer diameters are prone to sprocket shaking when the chain moves on these sprockets. Therefore, researchers in this field are currently working hard to solve the above-mentioned problem.

The present invention provides a bicycle rear flywheel that enables several sprockets with larger outer diameters to have sufficient structural strength to prevent the sprocket from shaking when the chain moves on one of the sprockets.

A bicycle rear flywheel disclosed in an embodiment of the present invention is used to be installed on a bicycle wheel hub, including a maximum sprocket, a first gasket, a first sprocket and a plurality of fasteners. The number of teeth of the maximum sprocket is greater than or equal to 40. The first gasket is connected to the maximum sprocket, and the first gasket has a plurality of first through holes. The first gasket is located between the first sprocket and the maximum sprocket, and the first sprocket has a plurality of internal spline teeth and a plurality of first assembly holes, and these internal spline teeth are used to be directly installed on the bicycle wheel hub. These fasteners pass through these first through holes of the first gasket and these first assembly holes of the first sprocket, respectively, to fasten the maximum sprocket, the first gasket and the first sprocket to each other.

Another embodiment of the present invention discloses a bicycle rear flywheel for installation on a bicycle wheel hub, comprising two sprockets and a plurality of fasteners. The two sprockets each have a plurality of assembly holes and a plurality of internal spline teeth for direct installation on the bicycle wheel hub. These fasteners pass through the assembly holes of the two sprockets respectively to fasten the two sprockets to each other. The number of teeth of the two sprockets is greater than or equal to 32.

According to the bicycle rear flywheel disclosed in the above embodiment, the first gasket is connected to the largest sprocket and is located between the first sprocket and the largest sprocket, and the fasteners pass through the first through holes of the first gasket and the first assembly holes of the first sprocket respectively, so that the largest sprocket, the first gasket and the first sprocket are fastened to each other, so that the largest sprocket, the first gasket and the first sprocket as a whole have sufficient structural strength to prevent the sprocket from shaking when the chain moves on the largest sprocket or the first sprocket.

The above description of the content of the present invention and the following description of the implementation method are used to demonstrate and explain the principle of the present invention, and provide a further explanation of the scope of the patent application of the present invention.

1: Bicycle rear flywheel

10: Largest sprocket

11: Inner Ring

111: Internal key teeth

12: Connecting arm

121: Assembly hole

13: External tooth ring

20: First gasket

21: Inner Ring

22: Connecting arm

221: First through hole

23: Outer Ring

30: Second large sprocket

31: Inner Ring

311: Internal key teeth

32: Connecting arm

321: Assembly hole

33: External tooth ring

40: Second gasket

41: Inner Ring

42: Connecting arm

421: Second through hole

43: Outer Ring

50: First sprocket

51: Inner Ring

511: Internal key teeth

512: screw hole

52: Connecting arm

521: First assembly hole

53: External tooth ring

60: Fasteners

61: Head

62: Body

621: Wide section

622: Narrow section

623: Riveting section

70: Third gasket

71: Internal key teeth

72: The third through hole

80: Second sprocket

81: Inner Ring

811: Internal key teeth

812: Second assembly hole

82: Connecting arm

83: External tooth ring

90: Fourth gasket

91: Internal key teeth

92: Fourth through hole

100: Third sprocket

1001: Inner Ring

10011: Internal key teeth

10012: The third assembly hole

1002: Connecting arm

1003: External tooth ring

110: Fifth gasket

1101: Internal key teeth

1102: Fifth through hole

120: Fourth sprocket

1201: Inner Ring

12011: Internal key teeth

12012: Fourth assembly hole

1202: Connecting arm

1203: External tooth ring

130: Stud

140: Sixth gasket

1401: Internal key teeth

150: Fifth sprocket

1501: Internal key teeth

160: Sixth sprocket

1601: Internal key teeth

170: Seventh Chain

1701: Internal key teeth

W1,W2,W3,W4:Width

C: Center

A: Axis

T:Distance

1a: Bicycle rear flywheel

10a: Largest sprocket

11a: Inner Ring

111a: Internal key teeth

12a: Connecting arm

121a: Assembly hole

13a: External tooth ring

20a: First gasket

21a: Inner Ring

211a: Internal key teeth

22a: Connecting arm

221a: first through hole

23a: Outer Ring

30a: Second large sprocket

31a: Inner Ring

311a: Internal spline teeth

32a: Connecting arm

321a: Assembly hole

33a: External tooth ring

40a: Second gasket

41a: Inner Ring

411a: Internal spline teeth

42a: Connecting arm

421a: Second through hole

43a: Outer Ring

50a: First sprocket

51a: Inner Ring

511a: Internal spline teeth

52a: Connecting arm

521a: First assembly hole

53a: External tooth ring

60a: Third gasket

61a: Inner Ring

62a: Connecting arm

621a: third through hole

70a: Second sprocket

71a: Inner Ring

711a: Internal spline teeth

712a: screw hole

72a: Connecting arm

721a: Second assembly hole

73a: External tooth ring

80a: Fasteners

81a:Head

82a: Body

821a: Wide section

822a: Narrow section

823a: Riveting section

90a: Fourth gasket

91a: Internal key teeth

92a: Fourth through hole

100a: Third sprocket

1001a: Inner Ring

10011a: Internal key teeth

10012a: The third assembly hole

1002a: Connecting arm

1003a: External tooth ring

110a: Fifth gasket

1101a: Internal spline teeth

1102a: fifth through hole

120a: Fourth sprocket

1201a: Inner Ring

12011a: Internal key teeth

12012a: Fourth assembly hole

1202a: Connecting arm

1203a: External tooth ring

130a: Sixth gasket

1301a: Internal key teeth

1302a: Sixth through hole

140a: Fifth sprocket

1401a: Inner Ring

14011a: Internal key teeth

14012a: Fifth assembly hole

1402a: Connecting arm

1403a: External tooth ring

150a: Seventh gasket

1501a: Internal spline teeth

1502a: Seventh through hole

160a: Sixth sprocket

1601a: Internal spline teeth

1602a: Sixth assembly hole

170a: Stud

180a: Seventh sprocket

1801a: Internal key teeth

190a: The eighth sprocket

1901a: Internal key teeth

W5,W6,W7,W8:Width

1b: Bicycle rear flywheel

10b: Largest sprocket

11b: Outer tooth ring

12b: Connecting arm

121b: Assembly hole

20b: First gasket

21b: Inner ring

211b: Internal key teeth

22b: Connecting arm

221b: first through hole

23b: Outer Ring

231b: Assembly hole

30b: Second large sprocket

31b: External tooth ring

32b: Connecting arm

321b: Assembly hole

40b: Second gasket

41b: Inner ring

411b: Internal spline teeth

42b: Connecting arm

421b: Second through hole

43b: Outer Ring

50b: First sprocket

51b: Inner ring

511b: Internal key teeth

52b: Connecting arm

521b: First assembly hole

53b: External tooth ring

60b: Third gasket

61b: Inner ring

62b: Connecting arm

621b: third through hole

70b: Second sprocket

71b: Inner ring

711b: Internal spline teeth

712b: screw hole

72b: Connecting arm

721b: Second assembly hole

73b: External tooth ring

80b: Fasteners

81b: Head

82b: Body

821b: Wide section

822b: Narrow segment

823b: Riveting section

90b: Fourth gasket

91b: Internal key teeth

92b: Fourth through hole

100b: Third sprocket

1001b: Inner Ring

10011b: Internal key teeth

10012b: The third assembly hole

1002b: Connecting arm

1003b: External tooth ring

110b: Fifth gasket

1101b: Internal spline teeth

1102b: fifth through hole

120b: Fourth sprocket

1201b: Inner ring

12011b: Internal key teeth

12012b: Fourth assembly hole

1202b: Connecting arm

1203b: External tooth ring

130b: Sixth gasket

1301b: Internal key teeth

1302b: Sixth through hole

140b: Fifth sprocket

1401b: Inner ring

14011b: Internal key teeth

14012b: Fifth assembly hole

1402b: Connecting arm

1403b: External tooth ring

150b: Seventh gasket

1501b: Internal key teeth

1502b: Seventh through hole

160b: Sixth sprocket

1601b: Inner ring

16011b: Internal spline teeth

16012b: Sixth assembly hole

1602b: Connecting arm

1603b: External tooth ring

170b: Eighth gasket

1701b: Internal key teeth

1702b: The eighth through hole

180b: Seventh sprocket

1801b: Internal key teeth

1802b: Seventh assembly hole

190b: Stud

200b: Eighth sprocket

2001b: Internal key teeth

210b: Ninth sprocket

2101b: Internal key teeth

F: Rivet

W9,W10,W11,W12: Width

Figure 1 is a three-dimensional schematic diagram of the rear flywheel of a bicycle disclosed according to the first embodiment of the present invention.

Figure 2 is a partially exploded schematic diagram of Figure 1.

Figure 3 is another partial decomposition diagram of Figure 1.

Figure 4 is a partial cross-sectional schematic diagram of Figure 1.

Figure 5 is a three-dimensional schematic diagram of the rear flywheel of a bicycle disclosed according to the second embodiment of the present invention.

Figure 6 is a partially exploded schematic diagram of Figure 5.

Figure 7 is another partial exploded schematic diagram of Figure 5.

Figure 8 is a partial cross-sectional schematic diagram of Figure 5.

Figure 9 is a three-dimensional schematic diagram of the rear flywheel of a bicycle disclosed in the third embodiment of the present invention.

Figure 10 is a partially exploded schematic diagram of Figure 9.

Figure 11 is another partial exploded schematic diagram of Figure 9.

Figure 12 is a partial cross-sectional schematic diagram of Figure 9.

Please refer to Figures 1 to 3. Figure 1 is a three-dimensional schematic diagram of the rear flywheel of a bicycle disclosed according to the first embodiment of the present invention. Figure 2 is a partially exploded schematic diagram of Figure 1. Figure 3 is another partially exploded schematic diagram of Figure 1.

In this embodiment, the bicycle rear flywheel 1 is used to be mounted on a bicycle wheel hub (not shown). The bicycle rear flywheel 1 includes a largest sprocket 10, a first gasket 20, a first sprocket 50 and a plurality of fasteners 60. In addition, the bicycle rear flywheel 1 may also include a primary large sprocket 30, a second gasket 40, a third gasket 70, a second sprocket 80, a fourth gasket 90, a third sprocket 100, a fifth gasket 110, a fourth sprocket 120, a sixth gasket 140, a fifth sprocket 150, a sixth sprocket 160 and a seventh sprocket 170.

Next, please refer to Figures 2 to 4 together. Figure 4 is a partial cross-sectional view of Figure 1.

In this embodiment, the largest sprocket 10, the second largest sprocket 30, the first sprocket 50, the second sprocket 80, the third sprocket 100, the fourth sprocket 120, the fifth sprocket 150, the sixth sprocket 160 and the seventh sprocket 170 are arranged in order from large to small in outer diameter. The first gasket 20 is located between the largest sprocket 10 and the second largest sprocket 30. The second gasket 40 is located between the second largest sprocket 30 and the first sprocket 50. The third gasket 70 is located between the first sprocket 50 and the second sprocket 80. The fourth gasket 90 is located between the second sprocket 80 and the third sprocket 100. The fifth gasket 110 is located between the third sprocket 100 and the fourth sprocket 120. The sixth gasket 140 is located between the fourth sprocket 120 and the fifth sprocket 150. The detailed structure of each sprocket and gasket will be introduced below.

The largest sprocket 10 includes an inner ring 11, a plurality of connecting arms 12 and an outer gear ring 13. The inner ring 11 is connected to the outer gear ring 13 through the connecting arms 12. The inner ring 11 has a plurality of inner spline teeth 111, which are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub. Each connecting arm 12 has an assembly hole 121. The number of teeth on the outer gear ring 13 is, for example, 46 teeth.

The first gasket 20 includes an inner ring 21, a plurality of connecting arms 22 and an outer ring 23. The inner ring 21 is connected to the outer ring 23 through the connecting arms 22. Each connecting arm 22 has a first through hole 221.

The secondary large chain wheel 30 includes an inner ring 31, a plurality of connecting arms 32 and an outer gear ring 33. The inner ring 31 is connected to the outer gear ring 33 through the connecting arms 32. The inner ring 31 has a plurality of inner spline teeth 311, which are used to be directly mounted on a plurality of tooth grooves of the bicycle wheel hub. Each connecting arm 32 has an assembly hole 321. The number of teeth on the outer gear ring 33 is, for example, 40 teeth.

The second gasket 40 includes an inner ring 41, a plurality of connecting arms 42 and an outer ring 43. The inner ring 41 is connected to the outer ring 43 through the connecting arms 42. Each connecting arm 42 has a second through hole 421.

The first sprocket 50 includes an inner ring 51, a plurality of connecting arms 52 and an outer gear ring 53. The inner ring 51 is connected to the outer gear ring 53 through the connecting arms 52. The inner ring 51 has a plurality of inner spline teeth 511 and a plurality of screw holes 512. The inner spline teeth 511 are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub. Each connecting arm 52 has a first assembly hole 521. The number of teeth on the outer gear ring 53 is, for example, 34 teeth.

These fasteners 60 are, for example, rivets. These fasteners 60 respectively pass through the assembly holes 121 of the largest sprocket 10, the first through holes 221 of the first gasket 20, the assembly holes 321 of the second largest sprocket 30, the second through holes 421 of the second gasket 40, and the first assembly holes 521 of the first sprocket 50, thereby fastening the largest sprocket 10, the first gasket 20, the second largest sprocket 30, the second gasket 40, and the first sprocket 50 to each other.

In detail, the structures of these fasteners 60 are the same, and only one of them is described in detail below. The fastener 60 includes a head 61 and a body 62, and the body 62 includes a wide section 621, a narrow section 622 and a riveting section 623. The wide section 621 is located between the head 61 and the narrow section 622 and connected to the head 61 and the narrow section 622, and the riveting section 623 is located on one side of the narrow section 622 away from the wide section 621. The width W1 of the head 61 is greater than the width W2 of the wide section 621, the width W2 of the wide section 621 is greater than the width W3 of the narrow section 622, and the width W4 of the rivet section 623 is greater than the width W3 of the narrow section 622. The heads 61 of the fasteners 60 abut against the largest sprocket 10, and the wide sections 621 of the body 62 of the fasteners 60 pass through the assembly holes 121 of the largest sprocket 10, the first through holes 221 of the first gasket 20, the assembly holes 321 of the second largest sprocket 30, and the second through holes 421 of the second gasket 40, respectively. The wide sections 621 of the body 62 of these fasteners 60 abut against the first sprocket 50, and the narrow sections 622 of these fasteners 60 pass through the first assembly holes 521 of the first sprocket 50 respectively. The largest sprocket 10, the first gasket 20, the second large sprocket 30, the second gasket 40 and the first sprocket 50 are clamped between the head 61 and the riveting section 623 of the body 62 of these fasteners 60, so that the largest sprocket 10, the first gasket 20, the second large sprocket 30, the second gasket 40 and the first sprocket 50 are fastened to each other, so the largest sprocket 10, the first gasket 20, the second large sprocket 30, the second gasket 40 and the first sprocket 50 have sufficient structural strength as a whole to prevent the sprocket from shaking when the chain moves on the largest sprocket 10, the second large sprocket 30 or the first sprocket 50.

In this embodiment, the distance T from the center C of these fasteners 60 to the rotation axis A of the rear flywheel 1 of the bicycle is, for example, at least 45.75 mm. In this way, the positions where the largest sprocket 10, the first gasket 20, the second large sprocket 30, the second gasket 40 and the first sprocket 50 are fastened to each other by these fasteners 60 are far enough away from the rotation axis A of the rear flywheel 1 of the bicycle, so that the overall structural strength of the largest sprocket 10, the first gasket 20, the second large sprocket 30, the second gasket 40 and the first sprocket 50 can be further enhanced. It should be noted that the distance T from the center C of these fasteners 60 to the rotation axis A of the rear flywheel 1 of the bicycle can be adjusted arbitrarily according to needs.

In this embodiment, the head 61 of the fasteners 60 abuts against the largest sprocket 10, and the wide section 621 of the body 62 of the fasteners 60 passes through the largest sprocket 10, the first gasket 20, the second largest sprocket 30 and the second gasket 40 and abuts against the first sprocket 50. The axial length of the wide section 621 of the fastener 60 can be used to limit the maximum sprocket 10 and the first sprocket 50, and the spacer is set between the adjacent two of the largest sprocket 10, the second largest sprocket 30 and the first sprocket 50, so that the axial distance between the largest sprocket 10, the second largest sprocket 30 and the first sprocket 50 can be fixed, thereby ensuring the flatness of the largest sprocket 10, the second largest sprocket 30 and the first sprocket 50.

It should be noted that the body 62 of the fastener 60 is not limited to including the wide section 621 and the narrow section 622. In other embodiments, the body of the fastener may be a column of uniform width except for the riveting section.

The third gasket 70 has a plurality of internal spline teeth 71 and a plurality of third through holes 72. The internal spline teeth 71 of the third gasket 70 are used to be directly mounted on a plurality of tooth grooves of the bicycle wheel hub, and the third through holes 72 correspond to the screw holes 512 of the first sprocket 50 respectively.

The second sprocket 80 includes an inner ring 81, a plurality of connecting arms 82 and an outer gear ring 83. The inner ring 81 is connected to the outer gear ring 83 through the connecting arms 82. The inner ring 81 has a plurality of inner spline teeth 811 and a plurality of second assembly holes 812. The inner spline teeth 811 are used to be directly mounted on a plurality of tooth grooves of the bicycle wheel hub, and the second assembly holes 812 correspond to the third through holes 72 of the third gasket 70. The number of teeth on the outer gear ring 83 is, for example, 28 teeth.

The fourth gasket 90 has a plurality of internal spline teeth 91 and a plurality of fourth through holes 92. The internal spline teeth 91 of the fourth gasket 90 are used to be directly mounted on a plurality of tooth grooves of the bicycle wheel hub, and the fourth through holes 92 correspond to the second assembly holes 812 of the inner ring 81 of the second sprocket 80, respectively.

The third sprocket 100 includes an inner ring 1001, a plurality of connecting arms 1002 and an outer gear ring 1003. The inner ring 1001 is connected to the outer gear ring 1003 through the connecting arms 1002. The inner ring 1001 has a plurality of inner spline teeth 10011 and a plurality of third assembly holes 10012. The inner spline teeth 10011 are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub, and the third assembly holes 10012 correspond to the fourth through holes 92 of the fourth gasket 90 respectively. The number of teeth on the outer gear ring 1003 is, for example, 24 teeth.

The fifth gasket 110 has a plurality of internal spline teeth 1101 and a plurality of fifth through holes 1102. The internal spline teeth 1101 of the fifth gasket 110 are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub, and the fifth through holes 1102 correspond to the third assembly holes 10012 of the inner ring 1001 of the third sprocket 100, respectively.

The fourth sprocket 120 includes an inner ring 1201, a plurality of connecting arms 1202 and an outer gear ring 1203. The inner ring 1201 is connected to the outer gear ring 1203 through the connecting arms 1202. The inner ring 1201 has a plurality of inner spline teeth 12011 and a plurality of fourth assembly holes 12012. The inner spline teeth 12011 are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub, and the fourth assembly holes 12012 correspond to the fifth through holes 1102 of the fifth gasket 110, respectively. The number of teeth on the outer gear ring 1203 is, for example, 20 teeth.

In this embodiment, the bicycle rear flywheel 1 may further include a plurality of studs 130 . The studs 130 respectively pass through the fourth assembly holes 12012 of the inner ring 1201 of the fourth sprocket 120, the fifth through holes 1102 of the fifth gasket 110, the third assembly holes 10012 of the inner ring 1001 of the third sprocket 100, the fourth through holes 92 of the fourth gasket 90, the second assembly holes 812 of the inner ring 81 of the second sprocket 80, and the third through holes 72 of the third gasket 70, and are screwed into the screw holes 512 of the first sprocket 50, so that the third gasket 70, the second sprocket 80, the fourth gasket 90, the third sprocket 100, the fifth gasket 110, and the fourth sprocket 120 are fastened between the heads of the studs 130 and the first sprocket 50.

It should be noted that the third gasket 70, the second sprocket 80, the fourth gasket 90, the third sprocket 100, the fifth gasket 110 and the fourth sprocket 120 are not limited to being fixed to the first sprocket 50 by the stud 130. In other embodiments, the third gasket, the second sprocket, the fourth gasket, the third sprocket, the fifth gasket and the fourth sprocket may be fixed to the first sprocket by rivets. In addition, the third gasket, the second sprocket, the fourth gasket, the third sprocket, the fifth gasket and the fourth sprocket may not be fixed to the first sprocket, and the studs or rivets may be omitted.

The sixth gasket 140 has a plurality of internal spline teeth 1401, and these internal spline teeth 1401 of the sixth gasket 140 are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub.

The fifth sprocket 150 has a plurality of internal spline teeth 1501, and these internal spline teeth 1501 of the fifth sprocket 150 are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub. The number of teeth of the fifth sprocket 150 is, for example, 16 teeth.

The sixth sprocket 160 has a plurality of internal spline teeth 1601, and these internal spline teeth 1601 of the sixth sprocket 160 are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub. The number of teeth of the sixth sprocket 160 is, for example, 13.

The seventh sprocket 170 has a plurality of internal spline teeth 1701, and these internal spline teeth 1701 of the seventh sprocket 170 are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub. The number of teeth of the seventh sprocket 170 is, for example, 11.

Please refer to Figures 5 to 7. Figure 5 is a three-dimensional schematic diagram of the rear flywheel of a bicycle disclosed according to the second embodiment of the present invention. Figure 6 is a partially exploded schematic diagram of Figure 5. Figure 7 is another partially exploded schematic diagram of Figure 5.

In this embodiment, the bicycle rear flywheel 1a is used to be mounted on a bicycle wheel hub (not shown). The bicycle rear flywheel 1a includes a largest sprocket 10a, a first gasket 20a, a first sprocket 50a and a plurality of fasteners 80a. In addition, the bicycle rear flywheel 1a may also include a primary large sprocket 30a, a second gasket 40a, a third gasket 60a, a second sprocket 70a, a fourth gasket 90a, a third sprocket 100a, a fifth gasket 110a, a fourth sprocket 120a, a sixth gasket 130a, a fifth sprocket 140a, a seventh gasket 150a, a sixth sprocket 160a, a seventh sprocket 180a and an eighth sprocket 190a.

Next, please refer to Figures 6 to 8 together. Figure 8 is a partial cross-sectional view of Figure 5.

In this embodiment, the largest sprocket 10a, the second largest sprocket 30a, the first sprocket 50a, the second sprocket 70a, the third sprocket 100a, the fourth sprocket 120a, the fifth sprocket 140a, the sixth sprocket 160a, the seventh sprocket 180a and the eighth sprocket 190a are arranged in order from large to small in outer diameter. The first gasket 20a is located between the largest sprocket 10a and the second largest sprocket 30a. The second gasket 40a is located between the second largest sprocket 30a and the first sprocket 50a. The third gasket 60a is located between the first sprocket 50a and the second sprocket 70a. The fourth gasket 90a is located between the second sprocket 70a and the third sprocket 100a. The fifth gasket 110a is located between the third sprocket 100a and the fourth sprocket 120a. The sixth gasket 130a is located between the fourth sprocket 120a and the fifth sprocket 140a. The seventh gasket 150a is located between the fifth sprocket 140a and the sixth sprocket 160a. The detailed structure of each sprocket and gasket will be introduced below.

The largest sprocket 10a includes an inner ring 11a, a plurality of connecting arms 12a and an outer gear ring 13a. The inner ring 11a is connected to the outer gear ring 13a through the connecting arms 12a. The inner ring 11a has a plurality of inner spline teeth 111a, which are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub. Each connecting arm 12a has an assembly hole 121a. The number of teeth on the outer gear ring 13a is, for example, 50 teeth.

The first gasket 20a includes an inner ring 21a, a plurality of connecting arms 22a and an outer ring 23a, wherein the inner ring 21a is connected to the outer ring 23a through the connecting arms 22a. The inner ring 21a has a plurality of inner spline teeth 211a, and the inner spline teeth 211a are used to be directly mounted on a plurality of tooth grooves of the bicycle wheel hub. Each connecting arm 22a has a first through hole 221a.

The secondary large chain wheel 30a includes an inner ring 31a, a plurality of connecting arms 32a and an outer gear ring 33a. The inner ring 31a is connected to the outer gear ring 33a through the connecting arms 32a. The inner ring 31a has a plurality of inner spline teeth 311a, which are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub. Each connecting arm 32a has an assembly hole 321a. The number of teeth on the outer gear ring 33a is, for example, 42 teeth.

The second gasket 40a includes an inner ring 41a, a plurality of connecting arms 42a and an outer ring 43a, wherein the inner ring 41a is connected to the outer ring 43a through the connecting arms 42a. The inner ring 41a has a plurality of inner spline teeth 411a, and the inner spline teeth 411a are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub. Each connecting arm 42a has a second through hole 421a.

The first sprocket 50a includes an inner ring 51a, a plurality of connecting arms 52a and an outer gear ring 53a. The inner ring 51a is connected to the outer gear ring 53a through the connecting arms 52a. The inner ring 51a has a plurality of inner spline teeth 511a, which are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub. Each connecting arm 52a has a first assembly hole 521a. The number of teeth on the outer gear ring 53a is, for example, 36 teeth.

The third gasket 60a includes an inner ring 61a and a plurality of connecting arms 62a connected to the outer side of the inner ring 61a. Each connecting arm 62a has a third through hole 621a.

The second sprocket 70a includes an inner ring 71a, a plurality of connecting arms 72a and an outer gear ring 73a. The inner ring 71a is connected to the outer gear ring 73a through the connecting arms 72a. The inner ring 71a has a plurality of inner spline teeth 711a and a plurality of screw holes 712a. The inner spline teeth 711a are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub. Each connecting arm 72a has a second assembly hole 721a. The number of teeth on the outer gear ring 73a is, for example, 32 teeth.

These fasteners 80a are, for example, rivets. These fasteners 80a respectively pass through the assembly holes 121a of the largest sprocket 10a, the first through holes 221a of the first gasket 20a, the assembly holes 321a of the second large sprocket 30a, the second through holes 421a of the second gasket 40a, the first assembly holes 521a of the first sprocket 50a, the third through holes 621a of the third gasket 60a, and the second assembly holes 721a of the second sprocket 70a, thereby fastening the largest sprocket 10a, the first gasket 20a, the second large sprocket 30a, the second gasket 40a, the first sprocket 50a, the third gasket 60a, and the second sprocket 70a to each other.

Specifically, the structures of these fasteners 80a are the same, and only one of them is described in detail below. The fastener 80a includes a head 81a and a body 82a, and the body 82a includes a wide section 821a, a narrow section 822a, and a riveting section 823a. The wide section 821a is located between the head 81a and the narrow section 822a and connected to the head 81a and the narrow section 822a, and the riveting section 823a is located on one side of the narrow section 822a away from the wide section 821a. The width W5 of the head portion 81a is greater than the width W6 of the wide section 821a, the width W6 of the wide section 821a is greater than the width W7 of the narrow section 822a, and the width W8 of the riveted section 823a is greater than the width W7 of the narrow section 822a. The heads 81a of the fasteners 80a abut against the largest sprocket 10a, and the wide sections 821a of the bodies 82a of the fasteners 80a respectively pass through the assembly holes 121a of the largest sprocket 10a, the first through holes 221a of the first gasket 20a, the assembly holes 321a of the second largest sprocket 30a, the second through holes 421a of the second gasket 40a, the first assembly holes 521a of the first sprocket 50a, and the third through holes 621a of the third gasket 60a. The wide sections 821a of the body 82a of these fasteners 80a abut against the second sprocket 70a, and the narrow sections 822a of these fasteners 80a pass through the second assembly holes 721a of the second sprocket 70a respectively. The largest sprocket 10a, the first gasket 20a, the second largest sprocket 30a, the second gasket 40a, the first sprocket 50a, the third gasket 60a and the second sprocket 70a are clamped between the head 81a and the riveting sections 823a of the body 82a of these fasteners 80a, so that the largest sprocket 10a, the first gasket 20a, the second largest sprocket 30a, the second gasket 40a, the first sprocket 50a, the third gasket 60a and the second sprocket 70a are clamped between the head 81a and the body 82a of these fasteners 80a. The plate 60a and the second sprocket 70a are fastened to each other, so the largest sprocket 10a, the first spacer 20a, the second largest sprocket 30a, the second spacer 40a, the first sprocket 50a, the third spacer 60a and the second sprocket 70a have sufficient structural strength as a whole to prevent the sprocket from shaking when the chain moves on the largest sprocket 10a, the second largest sprocket 30a, the first sprocket 50a or the second sprocket 70a.

In this embodiment, the distance T between the center C of the fasteners 80a and the rotation axis A of the bicycle rear flywheel 1a is, for example, at least 45.75 mm. Thus, the fasteners 80a can fasten the largest sprocket 10a, the first gasket 20a, the second largest sprocket 30a, the second gasket 40a, the first sprocket 50a, the third gasket 60a and the second sprocket 70a to each other at a position far enough from the rotation axis A of the bicycle rear flywheel 1a, so that the overall structural strength of the largest sprocket 10a, the first gasket 20a, the second largest sprocket 30a, the second gasket 40a, the first sprocket 50a, the third gasket 60a and the second sprocket 70a can be further enhanced. It should be noted that the distance T from the center C of these fasteners 80a to the rotation axis A of the bicycle rear flywheel 1a can be adjusted arbitrarily according to needs.

In this embodiment, the head 81a of the fasteners 80a abuts against the largest sprocket 10a, and the wide section 821a of the body 82a of the fasteners 80a passes through the largest sprocket 10a, the first gasket 20a, the second largest sprocket 30a, the second gasket 40a, the first sprocket 50a and the third gasket 60a and abuts against the second sprocket 70a. The axial length of the wide section 821a of the fastener 80a can be used to limit the maximum sprocket 10a. and the second sprocket 70a, and the spacer is provided between the adjacent two of the largest sprocket 10a, the second largest sprocket 30a, the first sprocket 50a and the second sprocket 70a, so that the axial distance between the largest sprocket 10a, the second largest sprocket 30a, the first sprocket 50a and the second sprocket 70a can be fixed, thereby ensuring the flatness of the largest sprocket 10a, the second largest sprocket 30a, the first sprocket 50a and the second sprocket 70a.

It should be noted that the body 82a of the fastener 80a is not limited to including the wide section 821a and the narrow section 822a. In other embodiments, the body of the fastener may be a column of uniform width except for the riveting section.

The fourth gasket 90a has a plurality of internal spline teeth 91a and a plurality of fourth through holes 92a. The internal spline teeth 91a of the fourth gasket 90a are used to be directly mounted on a plurality of tooth grooves of the bicycle wheel hub, and the fourth through holes 92a correspond to the screw holes 712a of the second sprocket 70a, respectively.

The third sprocket 100a includes an inner ring 1001a, a plurality of connecting arms 1002a and an outer gear ring 1003a. The inner ring 1001a is connected to the outer gear ring 1003a through the connecting arms 1002a. The inner ring 1001a has a plurality of inner spline teeth 10011a and a plurality of third assembly holes 10012a. The inner spline teeth 10011a are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub, and the third assembly holes 10012a correspond to the fourth through holes 92a of the fourth gasket 90a. The number of teeth on the outer gear ring is, for example, 28 teeth.

The fifth gasket 110a has a plurality of internal spline teeth 1101a and a plurality of fifth through holes 1102a. The internal spline teeth 1101a of the fifth gasket 110a are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub, and the fifth through holes 1102a correspond to the third assembly holes 10012a of the third sprocket 100a, respectively.

The fourth sprocket 120a includes an inner ring 1201a, a plurality of connecting arms 1202a and an outer gear ring 1203a. The inner ring 1201a is connected to the outer gear ring 1203a through the connecting arms 1202a. The inner ring 1201a has a plurality of inner spline teeth 12011a and a plurality of fourth assembly holes 12012a. The inner spline teeth 12011a are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub, and the fourth assembly holes 12012a correspond to the fifth through holes 1102a of the fifth gasket 110a. The number of teeth on the outer gear ring 1203a is, for example, 24 teeth.

The sixth gasket 130a has a plurality of internal spline teeth 1301a and a plurality of sixth through holes 1302a. The internal spline teeth 1301a of the sixth gasket 130a are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub, and the sixth through holes 1302a correspond to the fourth assembly holes 12012a of the fourth sprocket 120a, respectively.

The fifth sprocket 140a includes an inner ring 1401a, a plurality of connecting arms 1402a, and an outer gear ring 1403a. The inner ring 1401a is connected to the outer gear ring 1403a through the connecting arms 1402a. The inner ring 1401a has a plurality of inner spline teeth 14011a and a plurality of fifth assembly holes 14012a. The inner spline teeth 14011a are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub, and the fifth assembly holes 14012a correspond to the sixth through holes 1302a of the sixth gasket 130a. The number of teeth on the outer gear ring 1403a is, for example, 20 teeth.

The seventh gasket 150a has a plurality of internal spline teeth 1501a and a plurality of seventh through holes 1502a. The internal spline teeth 1501a of the seventh gasket 150a are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub, and the seventh through holes 1502a correspond to the fifth assembly holes 14012a of the fifth sprocket 140a, respectively.

The sixth sprocket 160a has a plurality of internal spline teeth 1601a and a plurality of sixth assembly holes 1602a. These internal spline teeth 1601a are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub, and these sixth assembly holes 1602a correspond to these seventh through holes 1502a of the seventh gasket 150a respectively. The number of teeth of the sixth sprocket 160a is, for example, 16.

In this embodiment, the bicycle rear flywheel 1a may further include a plurality of studs 170a. The studs 170a respectively pass through the sixth assembly holes 1602a of the sixth sprocket 160a, the seventh through holes 1502a of the seventh gasket 150a, the fifth assembly holes 14012a of the inner ring 1401a of the fifth sprocket 140a, the sixth through holes 1302a of the sixth gasket 130a, the fourth assembly holes 12012a of the inner ring 1201a of the fourth sprocket 120a, the fifth through holes 1102a of the fifth gasket 110a, and the fifth assembly holes 12012a of the inner ring 1201a of the fourth sprocket 120a. a, the third assembly holes 10012a of the inner ring 1001a of the third sprocket 100a and the fourth through holes 92a of the fourth gasket 90a are screwed into the screw holes 712a of the second sprocket 70a, so that the fourth gasket 90a, the third sprocket 100a, the fifth gasket 110a, the fourth sprocket 120a, the sixth gasket 130a, the fifth sprocket 140a, the seventh gasket 150a, and the sixth sprocket 160a are fastened to the second sprocket 70a.

It should be noted that the fourth shim 90a, the third sprocket 100a, the fifth shim 110a, the fourth sprocket 120a, the sixth shim 130a, the fifth sprocket 140a, the seventh shim 150a, and the sixth sprocket 160a are not limited to being fixed to the second sprocket 70a by the stud 170a. In other embodiments, the fourth shim, the third sprocket, the fifth shim, the fourth sprocket, the sixth shim, the fifth sprocket, the seventh shim, and the sixth sprocket may be fixed to the second sprocket by rivets. In addition, the fourth shim, the third sprocket, the fifth shim, the fourth sprocket, the sixth shim, the fifth sprocket, the seventh shim, and the sixth sprocket may not be fixed to the second sprocket, and the studs or rivets may be omitted.

The seventh sprocket 180a has a plurality of internal spline teeth 1801a, and these internal spline teeth 1801a of the seventh sprocket 180a are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub. The number of teeth of the seventh sprocket 180a is, for example, 13.

The eighth sprocket 190a has a plurality of internal spline teeth 1901a, and these internal spline teeth 1901a of the eighth sprocket 190a are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub. The number of teeth of the eighth sprocket 190a is, for example, 11.

Please refer to Figures 9 to 11. Figure 9 is a three-dimensional schematic diagram of the rear flywheel of a bicycle disclosed in the third embodiment of the present invention. Figure 10 is a partially exploded schematic diagram of Figure 9. Figure 11 is another partially exploded schematic diagram of Figure 9.

In this embodiment, the bicycle rear flywheel 1b is used to be mounted on a bicycle wheel hub (not shown). The bicycle rear flywheel 1b includes a largest sprocket 10b, a first gasket 20b, a first sprocket 50b and a plurality of fasteners 80b. In addition, the bicycle rear flywheel 1b may also include a primary large sprocket 30b, a second gasket 40b, a third gasket 60b, a second sprocket 70b, a fourth gasket 90b, a third sprocket 100b, a fifth gasket 110b, a fourth sprocket 120b, a sixth gasket 130b, a fifth sprocket 140b, a seventh gasket 150b, a sixth sprocket 160b, an eighth gasket 170b, a seventh sprocket 180b, an eighth sprocket 200b and a ninth sprocket 210b.

Next, please refer to Figures 10 to 12. Figure 12 is a partial cross-sectional view of Figure 9.

In this embodiment, the largest sprocket 10b, the second largest sprocket 30b, the first sprocket 50b, the second sprocket 70b, the third sprocket 100b, the fourth sprocket 120b, the fifth sprocket 140b, the sixth sprocket 160b, the seventh sprocket 180b, the eighth sprocket 200b and the ninth sprocket 210b are arranged in order from large to small in outer diameter. The first gasket 20b is located between the largest sprocket 10b and the second largest sprocket 30b. The second gasket 40b is at least partially located between the second largest sprocket 30b and the first sprocket 50b. The third gasket 60b is located between the first sprocket 50b and the second sprocket 70b. The fourth gasket 90b is located between the second sprocket 70b and the third sprocket 100b. The fifth gasket 110b is located between the third sprocket 100b and the fourth sprocket 120b. The sixth gasket 130b is located between the fourth sprocket 120b and the fifth sprocket 140b. The seventh gasket 150b is located between the fifth sprocket 140b and the sixth sprocket 160b. The eighth gasket 170b is located between the sixth sprocket 160b and the seventh sprocket 180b. The detailed structure of each sprocket and gasket will be introduced below.

The largest sprocket 10b includes an outer gear ring 11b and a plurality of connecting arms 12b protruding from the inner side of the outer gear ring 11b. Each connecting arm 12b has an assembly hole 121b. The number of teeth on the outer gear ring 11b is, for example, 50.

The first gasket 20b includes an inner ring 21b, a plurality of connecting arms 22b and an outer ring 23b, wherein the inner ring 21b is connected to the outer ring 23b through the connecting arms 22b. The inner ring 21b has a plurality of inner spline teeth 211b, which are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub. Each connecting arm 22b has a first through hole 221b, and the outer ring 23b has a plurality of assembly holes 231b.

The secondary large sprocket 30b includes an outer gear ring 31b and a plurality of connecting arms 32b protruding from the inner side of the outer gear ring 31b. Each connecting arm 32b has an assembly hole 321b. The number of teeth on the outer gear ring 31b is, for example, 42.

In this embodiment, the bicycle rear flywheel 1b may also include a plurality of rivets F. These rivets F respectively pass through the assembly holes 121b of the connecting arm 12b of the largest sprocket 10b, the assembly holes 231b of the outer ring 23b of the first gasket 20b, and the assembly holes 321b of the connecting arm 32b of the second largest sprocket 30b, thereby fixing the largest sprocket 10b and the second largest sprocket 30b to the first gasket 20b. The largest sprocket 10b and the second largest sprocket 30b are installed on the plurality of tooth grooves of the bicycle wheel hub through the inner spline teeth 211b of the first gasket 20b.

The second gasket 40b includes an inner ring 41b, a plurality of connecting arms 42b and an outer ring 43b, wherein the inner ring 41b is connected to the outer ring 43b through the connecting arms 42b. The inner ring 41b has a plurality of inner spline teeth 411b, and the inner spline teeth 411b are used to be directly mounted on a plurality of tooth grooves of the bicycle wheel hub. Each connecting arm 42b has a second through hole 421b.

The first sprocket 50b includes an inner ring 51b, a plurality of connecting arms 52b and an outer gear ring 53b. The inner ring 51b is connected to the outer gear ring 53b through the connecting arms 52b. The inner ring 51b has a plurality of inner spline teeth 511b, which are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub. Each connecting arm 52b has a first assembly hole 521b. The number of teeth on the outer gear ring 53b is, for example, 36 teeth.

The third gasket 60b includes an inner ring 61b and a plurality of connecting arms 62b connected to the outer side of the inner ring 61b. Each connecting arm 62b has a third through hole 621b.

The second sprocket 70b includes an inner ring 71b, a plurality of connecting arms 72b and an outer gear ring 73b. The inner ring 71b is connected to the outer gear ring 73b through the connecting arms 72b. The inner ring 71b has a plurality of inner spline teeth 711b and a plurality of screw holes 712b. The inner spline teeth 711b are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub. Each connecting arm 72b has a second assembly hole 721b. The number of teeth on the outer gear ring 73b is, for example, 32 teeth.

These fasteners 80b are, for example, rivets. These fasteners 80b respectively pass through the first through holes 221b of the first gasket 20b, the second through holes 421b of the second gasket 40b, the first assembly holes 521b of the first sprocket 50b, the third through holes 621b of the third gasket 60b, and the second assembly holes 721b of the second sprocket 70b, and fasten the largest sprocket 10b, the first gasket 20b, the second largest sprocket 30b, the second gasket 40b, the first sprocket 50b, the third gasket 60b, and the second sprocket 70b to each other.

In detail, the structures of these fasteners 80b are the same, and only one of them is described in detail below. The fastener 80b includes a head 81b and a body 82b, and the body 82b includes a wide section 821b, a narrow section 822b and a riveting section 823b. The wide section 821b is located between the head 81b and the narrow section 822b and connected to the head 81b and the narrow section 822b, and the riveting section 823b is located on one side of the narrow section 822b away from the wide section 821b. The width W9 of the head 81b is greater than the width W10 of the wide section 821b, the width W10 of the wide section 821b is greater than the width W11 of the narrow section 822b, and the width W12 of the riveting section 823b is greater than the width W11 of the narrow section 822b. The heads 81b of the fasteners 80b abut against the first gasket 20b, and the widths 821b of the bodies 82b of the fasteners 80b pass through the first through holes 221b of the first gasket 20b, the second through holes 421b of the second gasket 40b, the first assembly holes 521b of the first sprocket 50b, and the third through holes 621b of the third gasket 60b. The wide sections 821b of the body 82b of these fasteners 80b abut against the second sprocket 70b, and the narrow sections 822b of these fasteners 80b pass through the second assembly holes 721b of the second sprocket 70b respectively. The first gasket 20b, the second gasket 40b, the first sprocket 50b, the third gasket 60b and the second sprocket 70b are clamped between the head 81b and the riveting sections 823b of the body 82b of these fasteners 80b, so that the largest sprocket 10b, the first gasket 20b, the second largest sprocket 30b, the second gasket 40b, the first sprocket 50b, the third gasket 60b and the second sprocket 70b are clamped. The wheels 70b are fastened to each other, so the largest sprocket 10b, the first gasket 20b, the second largest sprocket 30b, the second gasket 40b, the first sprocket 50b, the third gasket 60b and the second sprocket 70b have sufficient structural strength as a whole to prevent the sprocket from shaking when the chain moves on the largest sprocket 10b, the second largest sprocket 30b, the first sprocket 50b or the second sprocket 70b.

In this embodiment, the distance T between the center C of the fasteners 80b and the rotation axis A of the rear flywheel 1b of the bicycle is, for example, at least 45.75 mm. Thus, the fasteners 80b can fasten the largest sprocket 10b, the first gasket 20b, the second largest sprocket 30b, the second gasket 40b, the first sprocket 50b, the third gasket 60b and the second sprocket 70b to each other at a position far enough from the rotation axis A of the rear flywheel 1b of the bicycle, so that the overall structural strength of the largest sprocket 10b, the first gasket 20b, the second largest sprocket 30b, the second gasket 40b, the first sprocket 50b, the third gasket 60b and the second sprocket 70b can be further enhanced. It should be noted that the distance T from the center C of these fasteners 80b to the rotation axis A of the bicycle rear flywheel 1b can be adjusted arbitrarily according to needs.

In this embodiment, the head 81b of the fasteners 80b abuts against the first gasket 20b, and the wide section 821b of the body 82b of the fasteners 80b passes through the first gasket 20b, the second gasket 40b, the first sprocket 50b and the third gasket 60b and abuts against the second sprocket 70b. The axial length of the wide section 821b of the fastener 80b can be used to limit the first gasket 20b and the second sprocket 70b. The axial distance between the largest sprocket 10b, the second largest sprocket 30b, the first sprocket 50b and the second sprocket 70b, plus the spacer between the adjacent two of them, can fix the axial distance between the largest sprocket 10b, the second largest sprocket 30b, the first sprocket 50b and the second sprocket 70b, and ensure the flatness of the largest sprocket 10b, the second largest sprocket 30b, the first sprocket 50b and the second sprocket 70b.

It should be noted that the body 82b of the fastener 80b is not limited to including the wide section 821b and the narrow section 822b. In other embodiments, the body of the fastener may be a column of uniform width except for the riveting section.

The fourth gasket 90b has a plurality of internal spline teeth 91b and a plurality of fourth through holes 92b. The internal spline teeth 91b of the fourth gasket 90b are used to be directly mounted on a plurality of tooth grooves of the bicycle wheel hub, and the fourth through holes 92b correspond to the screw holes 712b of the second sprocket 70b respectively.

The third sprocket 100b includes an inner ring 1001b, a plurality of connecting arms 1002b and an outer gear ring 1003b. The inner ring 1001b is connected to the outer gear ring 1003b through the connecting arms 1002b. The inner ring 1001b has a plurality of inner spline teeth 10011b and a plurality of third assembly holes 10012b. The inner spline teeth 10011b are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub, and the third assembly holes 10012b correspond to the fourth through holes 92b of the fourth gasket 90b. The number of teeth on the outer gear ring 1003b is, for example, 28 teeth.

The fifth gasket 110b has a plurality of internal spline teeth 1101b and a plurality of fifth through holes 1102b. The internal spline teeth 1101b of the fifth gasket 110b are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub, and the fifth through holes 1102b correspond to the third assembly holes 10012b of the third sprocket 100b, respectively.

The fourth sprocket 120b includes an inner ring 1201b, a plurality of connecting arms 1202b and an outer gear ring 1203b. The inner ring 1201b is connected to the outer gear ring 1203b through the connecting arms 1202b. The inner ring 1201b has a plurality of inner spline teeth 12011b and a plurality of fourth assembly holes 12012b. The inner spline teeth 12011b are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub, and the fourth assembly holes 12012b correspond to the fifth through holes 1102b of the fifth gasket 110b. The number of teeth on the outer gear ring 1203b is, for example, 24 teeth.

The sixth gasket 130b has a plurality of internal spline teeth 1301b and a plurality of sixth through holes 1302b. The internal spline teeth 1301b of the sixth gasket 130b are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub, and the sixth through holes 1302b correspond to the fourth assembly holes 12012b of the fourth sprocket 120b, respectively.

The fifth sprocket 140b includes an inner ring 1401b, a plurality of connecting arms 1402b and an outer gear ring 1403b. The inner ring 1401b is connected to the outer gear ring 1403b through the connecting arms 1402b. The inner ring 1401b has a plurality of inner spline teeth 14011b and a plurality of fifth assembly holes 14012b. The inner spline teeth 14011b are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub, and the fifth assembly holes 14012b correspond to the sixth through holes 1302b of the sixth gasket 130b, respectively. The number of teeth on the outer gear ring 1403b is, for example, 21 teeth.

The seventh gasket 150b has a plurality of inner spline teeth 1501b and a plurality of seventh through holes 1502b. The inner spline teeth 1501b of the seventh gasket 150b are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub, and the seventh through holes 1502b correspond to the fifth assembly holes 14012b of the fifth sprocket 140b, respectively.

The sixth sprocket 160b includes an inner ring 1601b, a plurality of connecting arms 1602b and an outer gear ring 1603b. The inner ring 1601b is connected to the outer gear ring 1603b through the connecting arms 1602b. The inner ring 1601b has a plurality of inner spline teeth 16011b and a plurality of sixth assembly holes 16012b. The inner spline teeth 16011b are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub, and the sixth assembly holes 16012b correspond to the seventh through holes 1502b of the seventh gasket 150b. The number of teeth on the outer gear ring 1603b is, for example, 18 teeth.

The eighth gasket 170b has a plurality of internal spline teeth 1701b and a plurality of eighth through holes 1702b. The internal spline teeth 1701b of the eighth gasket 170b are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub, and the eighth through holes 1702b correspond to the sixth assembly holes 16012b of the sixth sprocket 160b, respectively.

The seventh sprocket 180b has a plurality of inner spline teeth 1801b and a plurality of seventh assembly holes 1802b. These inner spline teeth 1801b are used to be directly mounted on a plurality of tooth grooves of the bicycle wheel hub, and these seventh assembly holes 1802b correspond to these eighth through holes 1702b of the eighth gasket 170b respectively. The number of teeth of the sixth sprocket 160b is, for example, 15 teeth.

In this embodiment, the bicycle rear flywheel 1b may also include a plurality of studs 190b. The studs 190b respectively pass through the seventh assembly holes 1802b of the seventh sprocket 180b, the eighth through holes 1702b of the eighth gasket 170b, the sixth assembly holes 16012b of the sixth sprocket 160b, the seventh through holes 1502b of the seventh gasket 150b, the fifth assembly holes 14012b of the inner ring 1401b of the fifth sprocket 140b, the sixth through holes 1302b of the sixth gasket 130b, the fourth assembly holes 12012b of the inner ring 1201b of the fourth sprocket 120b, and the fifth gasket 1 10b, the third assembly holes 10012b of the inner ring 1001b of the third sprocket 100b, and the fourth through holes 92b of the fourth gasket 90b, and screwed into the screw holes 712b of the second sprocket 70b, so that the fourth gasket 90b, the third sprocket 100b, the fifth gasket 110b, the fourth sprocket 120b, the sixth gasket 130b, the fifth sprocket 140b, the seventh gasket 150b, the sixth sprocket 160b, the eighth gasket 170b and the seventh sprocket 180b are fastened to the second sprocket 70b.

It should be noted that the fourth shim 90b, the third sprocket 100b, the fifth shim 110b, the fourth sprocket 120b, the sixth shim 130b, the fifth sprocket 140b, the seventh shim 150b, the sixth sprocket 160b, the eighth shim 170b and the seventh sprocket 180b are not limited to being fixed to the second sprocket 70b by the stud 190b. In other embodiments, the fourth shim, the third sprocket, the fifth shim, the fourth sprocket, the sixth shim, the fifth sprocket, the seventh shim, the sixth sprocket, the eighth shim and the seventh sprocket may be fixed to the second sprocket by rivets. In addition, the fourth shim, the third sprocket, the fifth shim, the fourth sprocket, the sixth shim, the fifth sprocket, the seventh shim, the sixth sprocket, the eighth shim and the seventh sprocket may not be fixed to the second sprocket, and the studs or rivets may be omitted.

The eighth sprocket 200b has a plurality of internal spline teeth 2001b, and these internal spline teeth 2001b of the eighth sprocket 200b are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub. The number of teeth of the eighth sprocket 200b is, for example, 13.

The ninth sprocket 210b has a plurality of internal spline teeth 2101b, and these internal spline teeth 2101b of the ninth sprocket 210b are used to be directly mounted on a plurality of tooth grooves of a bicycle wheel hub. The number of teeth of the ninth sprocket 210b is, for example, 11.

According to the bicycle rear flywheel disclosed in the above embodiment, the first gasket is connected to the largest sprocket and is located between the first sprocket and the largest sprocket, and the fasteners pass through the first through holes of the first gasket and the first assembly holes of the first sprocket respectively, so that the largest sprocket, the first gasket and the first sprocket are fastened to each other, so that the largest sprocket, the first gasket and the first sprocket as a whole have sufficient structural strength to prevent the sprocket from shaking when the chain moves on the largest sprocket or the first sprocket.

In addition, the distance from the center of the fastener to the rotation axis of the rear flywheel of the bicycle is at least 45.75 mm, so that the position where the fastener fastens the largest sprocket, the first spacer and the first sprocket to each other is far enough away from the rotation axis of the rear flywheel of the bicycle, so that the overall structural strength of the largest sprocket, the first spacer and the first sprocket can be further enhanced.

Although the present invention is disclosed as above with the aforementioned preferred embodiment, it is not used to limit the present invention. Anyone familiar with similar techniques can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of patent protection of the present invention shall be subject to the scope of the patent application attached to this specification.

10: Largest sprocket 20: First shim 30: Second largest sprocket 40: Second shim 50: First sprocket 60: Fastener 70: Third shim 80: Second sprocket 90: Fourth shim 100: Third sprocket 110: Fifth shim 120: Fourth sprocket 130: Stud 140: Sixth shim 160: Sixth sprocket 170: Seventh sprocket W1,W2,W3,W4: Width C: Center A: Axis T: Distance

Claims (7)

A bicycle rear flywheel is used to be installed on a bicycle wheel hub, comprising: a largest sprocket, the number of teeth of the largest sprocket is greater than or equal to 40; a first gasket connected to the largest sprocket, the first gasket having a plurality of first through holes; a first sprocket, the first gasket is located between the first sprocket and the largest sprocket, the first sprocket having a plurality of internal spline teeth and a plurality of first assembly holes, the internal spline teeth being used to be directly installed on the bicycle wheel hub; and a plurality of fasteners, respectively passing through the first through holes of the first gasket and the first assembly holes of the first sprocket, so as to fasten the bicycle wheel hub to the rear flywheel. The largest sprocket, the first gasket and the first sprocket are fastened to each other; wherein the largest sprocket has a plurality of assembly holes and a plurality of internal spline teeth for being directly mounted on the bicycle wheel hub, and the fasteners respectively pass through the assembly holes of the largest sprocket, the first through holes of the first gasket and the first assembly holes of the first sprocket to fasten the largest sprocket, the first gasket and the first sprocket to each other; wherein the bicycle rear flywheel further includes a primary large sprocket and a second gasket, the first gasket is located between the secondary large sprocket and the largest sprocket, and the second gasket is located between the secondary large sprocket and the largest sprocket. The second large sprocket has a plurality of assembly holes and a plurality of internal spline teeth for being directly mounted on the wheel hub of the bicycle, and the second gasket has a plurality of second through holes. The fasteners respectively pass through the assembly holes of the largest sprocket, the first through holes of the first gasket, the assembly holes of the second large sprocket, the second through holes of the second gasket, and the first assembly holes of the first sprocket to fasten the largest sprocket, the first gasket, the second large sprocket, the second gasket, and the first sprocket to each other; wherein each of the fasteners includes a head portion and a body portion, The body includes a wide section and a narrow section, the wide section is located between the head and the narrow section and connected to the head and the narrow section, the width of the head is greater than the width of the wide section, and the width of the wide section is greater than the width of the narrow section; the heads abut against the largest sprocket, the wide sections of the bodies respectively pass through the assembly holes of the largest sprocket, the first through holes of the first gasket, the assembly holes of the secondary large sprocket and the second through holes of the second gasket, the wide sections of the bodies abut against the first sprocket, and the narrow sections respectively pass through the first assembly holes of the first sprocket. A bicycle rear flywheel as described in claim 1, wherein the number of teeth of the secondary sprocket and the number of teeth of the first sprocket are both greater than or equal to 32. A bicycle rear flywheel is used to be installed on a bicycle wheel hub, comprising: a largest sprocket, the number of teeth of the largest sprocket is greater than or equal to 40; a first gasket connected to the largest sprocket, the first gasket having a plurality of first through holes; a first sprocket, the first gasket is located between the first sprocket and the largest sprocket, the first sprocket having a plurality of internal spline teeth and a plurality of first assembly holes, the first gasket being ... The inner spline teeth are used to be directly mounted on the bicycle wheel hub; and a plurality of fasteners are respectively passed through the first through holes of the first gasket and the first assembly holes of the first sprocket to fasten the largest sprocket, the first gasket and the first sprocket to each other; wherein the largest sprocket has a plurality of assembly holes and a plurality of inner spline teeth for being directly mounted on the bicycle wheel hub, and the fasteners are respectively passed through the first through holes of the first gasket and the first assembly holes of the first sprocket. The largest sprocket, the first gasket and the first sprocket are fastened to each other through the assembly holes of the largest sprocket, the first through holes of the first gasket and the first assembly holes of the first sprocket; wherein the bicycle rear flywheel further comprises a primary large sprocket and a second gasket, the first gasket is located between the secondary large sprocket and the largest sprocket, the second gasket is located between the secondary large sprocket and the first sprocket The second large chain wheel has a plurality of assembly holes and a plurality of internal spline teeth for being directly mounted on the bicycle wheel hub, the second gasket has a plurality of second through holes, the fasteners respectively pass through the assembly holes of the largest chain wheel, the first through holes of the first gasket, the assembly holes of the second large chain wheel, the second through holes of the second gasket and the first assembly holes of the first chain wheel, and the The largest sprocket, the first washer, the second largest sprocket, the second washer and the first sprocket are fastened to each other; wherein the bicycle rear flywheel further comprises a third washer and a second sprocket, the third washer is located between the first sprocket and the second sprocket, the third washer has a third through hole, the second sprocket has a plurality of second assembly holes and a plurality of internal splines for being directly mounted on the bicycle wheel hub The fasteners respectively pass through the assembly holes of the largest sprocket, the first through holes of the first gasket, the assembly holes of the secondary large sprocket, the second through holes of the second gasket, the first assembly holes of the first sprocket, the third through holes of the third gasket and the second assembly holes of the second sprocket, thereby fastening the largest sprocket, the first gasket, the secondary large sprocket, the second gasket The first sprocket, the third spacer and the second sprocket are fastened to each other; wherein each of the fasteners includes a head and a body, the body includes a wide section and a narrow section, the wide section is located between the head and the narrow section and connected to the head and the narrow section, the width of the head is greater than the width of the wide section, and the width of the wide section is greater than the width of the narrow section; the heads are against the largest sprocket, and the bodies are The wide sections of the body respectively pass through the assembly holes of the largest sprocket, the first through holes of the first gasket, the assembly holes of the second-largest sprocket, the second through holes of the second gasket, the first assembly holes of the first sprocket and the third through holes of the third gasket, the wide sections of the body abut against the second sprocket, and the narrow sections pass through the second assembly holes of the second sprocket. A bicycle rear flywheel is used to be installed on a bicycle wheel hub, comprising: a largest sprocket, the number of teeth of the largest sprocket is greater than or equal to 40; a first gasket connected to the largest sprocket, the first gasket having a plurality of first through holes; a first sprocket, the first gasket is located between the first sprocket and the largest sprocket, the first sprocket having a plurality of internal spline teeth and a plurality of first assembly holes, the internal spline teeth being used to be directly installed on the bicycle wheel hub; and a plurality of fasteners, respectively passing through the first through holes and the first through holes of the first gasket The first assembly holes of the sprocket are connected to the largest sprocket, the first gasket and the first sprocket to each other; wherein the first gasket has a plurality of internal spline teeth for direct installation on the bicycle wheel hub, the largest sprocket is fixed to the first gasket and installed on the bicycle wheel hub through the first gasket; wherein the bicycle rear flywheel further includes a primary large sprocket and a second gasket, the first gasket is located between the largest sprocket and the secondary large sprocket, the secondary large sprocket is fixed to the first gasket and installed on the bicycle wheel hub through the first gasket , the second gasket is at least partially located between the secondary large sprocket and the first sprocket, the second gasket has a plurality of second through holes, the fasteners respectively pass through the first through holes of the first gasket, the second through holes of the second gasket and the first assembly holes of the first sprocket, and fasten the largest sprocket, the first gasket, the secondary large sprocket, the second gasket and the first sprocket to each other; wherein the bicycle rear flywheel further includes a third gasket and a second sprocket, the third gasket is located between the first sprocket and the second sprocket, the third gasket is located between the first sprocket and the second sprocket, the third The three washers have a plurality of third through holes, the second sprocket has a plurality of second assembly holes and a plurality of internal spline teeth for direct installation on the bicycle wheel hub, and the fasteners respectively pass through the first through holes of the first washers, the second through holes of the second washers, the first assembly holes of the first sprocket, the third through holes of the third washers, and the second assembly holes of the second sprocket, thereby fastening the largest sprocket, the first washers, the second-largest sprocket, the second washers, the first sprocket, the third washers, and the second sprocket to each other. A bicycle rear flywheel as described in claim 4, wherein each of the fasteners comprises a head and a body, the body comprises a wide section and a narrow section, the wide section is located between the head and the narrow section and connected to the head and the narrow section, the width of the head is greater than the width of the wide section, and the width of the wide section is greater than the width of the narrow section; the heads abut against the first gasket, the wide sections of the bodies respectively pass through the first through holes of the first gasket, the second through holes of the second gasket, the first assembly holes of the first sprocket, and the third through holes of the third gasket, the wide sections of the bodies abut against the second sprocket, and the narrow sections pass through the second assembly holes of the second sprocket. The bicycle rear flywheel as described in claim 4, wherein the number of teeth of the first sprocket and the number of teeth of the second sprocket are both greater than or equal to 32. A bicycle rear flywheel as described in claim 1, 3 or 4, wherein the distance from the center of the fasteners to the rotation axis of the bicycle rear flywheel is at least 45.75 mm.