TWI511902B - Eight-speed transmission hub for bicycle - Google Patents

Description

Bicycle eight-speed internal transmission

The present invention relates to a bicycle shifting device, and more particularly to a bicycle eight-speed internal transmission.

The classification of bicycle transmissions can be divided into two types: external gearbox (Derailleur) and internal transmission (transmission hub). They are all placed on the rear wheel hub of the bicycle. The general internal transmission is usually a planetary gear train. As the main body of the shifting mechanism, the gearbox shaft and other shifting and transmission parts are completely covered in the rear wheel hub of the bicycle, and the power is input by the sprocket, and the shifting mechanism is switched by switching different input parts, output parts and fixing parts. After changing the speed and torque, the power is output to the rear wheel for the purpose of multi-speed shifting.

The advantage of the external transmission is that the mechanism is simple and inexpensive, and it is generally used on low- and medium-priced bicycles. However, such a shifting system is susceptible to the external environment, and the shifting gear often has troubles in shifting gears and derailment of the chain; The transmission has the following advantages:

1. Small size and compact structure, not easy to be limited by the narrow wheel space limitation.

2. The shifting operation is stable, and the chain will not be de-chained due to the gear position change.

3. With the protection of the hub shell, it is not easy to be damaged by impact or external environment, and has a long service life.

Since the internal transmission has many advantages that the external transmission lacks, electric bicycles and light electric vehicles that are popular in the market in recent years are gradually equipped with internal transmissions, and research results on bicycle internal transmissions are mostly concentrated on the planets. The related theory of the gear train speed change mechanism is rarely discussed in the design theory of the speed governing mechanism and the integration of the shifting mechanism and the speed governing mechanism. The invention patent case of the patent bicycle number I323232 "Bicycle 16-speed internal transmission device" is disclosed. An existing internal transmission in which a large number of components and a complicated shifting process are necessary to simplify and strengthen.

In order to solve the problem that the existing internal transmission components are numerous and the shifting process is complicated, the main object of the present invention is to provide a bicycle eight-speed internal transmission, which is designed with a split-flow mechanism and a speed governing mechanism, and can rotate the power input speed twice. Variable speed output for multi-speed shifting in a limited configuration space and simplifies construction and shifting.

The technical means used in the present invention is to provide a bicycle eight-speed internal transmission, comprising: a hub unit comprising a cylindrical casing, two side covers respectively coupled to the two sides of the casing, and an axial wear Providing the housing and fixing to the main shaft of the two side covers and a speed regulating mechanism slidably disposed inside the main shaft, the speed regulating mechanism includes a speed regulating sliding rod, which is along the axial direction of the main shaft Translational sliding, and the protrusion is provided with a plurality of convex teeth with different intervals, each convex tooth protrudes from the main shaft, and the number of convex teeth of each convex tooth is twelve, and the optimal design width is 3 mm, and each A gap of 0.5 mm is required at both ends of the convex tooth; a transmission unit is fixed to one side of the hub unit; a first shifting unit is sleeved and coupled to the main shaft of the hub unit, and is coupled to the a transmission unit, the first shifting unit includes a speed control ring, a first ring gear, a first planetary arm, a plurality of first planetary gears, a plurality of second planetary gears, a first sun gear, and a second too a male gear, the speed control ring is sleeved on the main shaft and connected to the transmission unit, the first ring gear is sleeved on the outer circumference of the speed control ring, and the first planetary arm is connected to the outer circumference of the speed control ring And located in front of the first ring gear, the plurality of first planetary gears and the plurality of second planetary gear systems are respectively disposed on the first planetary arm, and each of the first and second planetary gear trains are rotatable and respectively waitable The first sun gear and the second sun gear are respectively sleeved on the outer circumference of the main shaft and the speed adjustment mechanism, and can be adjusted by the adjustment mechanism to make the The first sun gear can be correspondingly engaged with each of the first planet gears, or the second sun gear can be correspondingly engaged with each of the second planet gears, the first ring gear train being rotatable and selectively connectable to the speed control ring or the a first planetary gear; a second shifting unit coupled to the main shaft of the hub unit and coupled to the first shifting unit, and including a second ring gear, a plurality of third planetary gears and a third Sun gear, The second ring gear is sleeved on the main shaft, and is rotatably and selectively connected to the planetary arm or the second planetary gear of the first shifting unit, and the third planetary gear train is equally spaced on the second ring. a third sun gear system sleeve is coupled to the outer circumference of the main shaft and the speed control mechanism, and can be adjusted by the adjustment mechanism, so that the third sun gear can be correspondingly engaged with each of the third planetary gears; The differential unit includes a ring sleeve and a plurality of planetary gears, and the ring sleeve is rotatably sleeved on the main shaft and surrounds the first shifting unit and the outer periphery of the second shifting unit, and the The ring sleeve is selectively connected to the second ring gear or the third planetary gears of the second shifting unit, and the planetary gears are equally disposed around the rear end of the differential unit and are engaged with the first shifting gear. Ring gear of the unit and the outer casing of the hub unit Inside.

The bicycle eight-speed internal transmission, wherein the speed control ring of the first shifting unit can be clamped to the first ring gear by a first clutch, and the second planetary gear can be engaged with the second ring gear by the second clutch The second ring gear can be clamped to the ring sleeve by a third clutch, and the first, second, and third clutches are all one-way pawl clutches.

The improvement achieved by the present invention is an eight-speed split internal transmission that integrates a split-flow mechanism and a speed governing mechanism, and the composition includes a differential unit and two shifting units, and is a set of planetary differential gears with a degree of freedom of two. Department, with two sets of planetary gear trains, the input power transmitted by the sprocket is divided into two parts. By the speed of the two sets of planetary gear trains, the speed of the power input can be output twice, and By increasing the order of the planetary gear train, it is possible to achieve multi-speed shifting in a limited configuration space. At the same time, the present invention has a compact structure, easy shifting, and an average transmission efficiency of 98.58%, which is a relatively high efficiency bicycle shifter.

In order to be able to understand the technical features and practical functions of the present invention in detail, and in accordance with the contents of the specification, further illustrated in the following preferred embodiments, the following is a bicycle eight-speed internal transmission. Please refer to the preferred embodiment of FIG. 1 , which includes a hub unit 10 , a transmission unit 20 , a first shifting unit 30 , a second shifting unit 40 and a differential unit 50 , wherein the hub unit 10 The utility model comprises a casing 11, a side cover 12, a main shaft 13 and a speed regulating mechanism 14. The casing 11 has a cylindrical shape, and the casing 11 is formed on an inner wall adjacent to the one side cover 12 to form an internal tooth. Face 111, the two side covers 12 are respectively Covering the two sides of the housing 11, the main shaft 13 is bored along the axial direction of the housing 11 and fixed to the two side covers 12, and the main shaft 13 can be fixed to a frame (not shown) The housing 11 and the two side covers 12 are rotated about the main shaft 13. The main shaft 13 is hollow and has a long sliding groove 131 on the pipe wall. The speed regulating mechanism 14 is Slidingly disposed in the main shaft 13 and including a compression spring 141, a speed control slide 142, a pull rod 143 and a tension spring 144, the compression spring 141 is fixed at one end inside the main shaft 13, and is The speed control slide 142 is elastically stretchably coupled to the other end, and the speed control slide 142 is slidably movable along the axial direction of the main shaft 13, and is convexly provided with a plurality of convexities with different intervals and a rectangular shape. The number of the teeth 1421 is preferably twelve, and the convex teeth 1421 protrude from the sliding groove 131 of the main shaft 13. The optimal design width of each convex tooth 1421 is 3 mm, and the convex teeth 1421 are A clearance of 0.5 mm is required at both ends to ensure that there is no interference when shifting, and the pull rod 143 is connected to the speed control slider 142 to be different from the compression spring. One side of the 141 extends to the outside of the main shaft 13. The tension spring 144 is sleeved on the outer circumference of the rod 143 and coupled to the speed control slider 142. The rod 143 can be coupled to a shifting mechanism (Fig. Not shown), the shifting mechanism adjusts the pulling of the pull rod 143, and the speed adjusting slider 142 is slidably linked, thereby causing the displacement of the protruding teeth 1421 to produce a shifting effect.

The transmission unit 20 is a sprocket device and is coupled to one side of the wheel housing unit 10, and the one side cover 12 is covered on the outer side of the transmission unit 20, and the transmission unit 20 is defined. The side is the rear end and the other side is the front end; the transmission unit 20 includes a sprocket seat 21 and a chain plate 22, the sprocket seat 21 is cylindrical and sleeved and coupled to the main shaft 13 and Rotatingly connected On one side of the housing 11, the sprocket 22 is sleeved and fixed on the outer side of the sprocket seat 21. The transmission unit 20 is connected to a chain transmission device (not shown), and is driven by human or mechanical power. The sprocket seat 21 generates rotation and transmits power to other parts. Since the transmission unit 20 is prior art and non-emphasis, it will not be described.

The first shifting unit 30 is sleeved and coupled to the main shaft 13 of the hub unit 10, and is coupled to the transmission unit 20. The first shifting unit 30 includes a speed regulating ring 31, a first ring gear 32, and a first shifting gear unit. a first planetary arm 33, three first planetary gears 34, three second planetary gears 35, a first sun gear 36 and a second sun gear 37; wherein the speed regulating ring 31 is sleeved on the main shaft 13 A first clutch 311 is disposed on the outer circumference of the sprocket seat 21, and an engagement end 312 is formed on the outer end of the speed control ring 31. The first ring gear 32 is formed. The first ring gear 32 is correspondingly sleeved with the first clutch 311 of the speed regulating ring 31 by the through hole 321 , and the first ring gear 32 is disposed in the middle of the cylinder. A clutch 311 is correspondingly engaged with the through hole 321 , and an outer ring tooth 322 is formed on the outer side of the first ring gear 32 , and an inner ring tooth 323 is formed on the inner side of the front end. Cylindrical and sleeved on the outer circumference of the speed control ring 31, and one end is engaged with the meshing end 312, and on the first planet A second clutch 331 is disposed at a front end of the arm 33. The first clutch 311 and the second clutch 331 are both one-way pawl clutches; each of the first planetary gears 34 and each of the second planetary gears 35 are disposed from the rear to the front. The first planetary gears 33 and the first planetary gears 34 and the second planetary gears 35 are respectively rotatable and spaced apart from each other around the first planetary arm 33. The first sun gear 36 and the second sun gear 37 are respectively sleeved from the rear to the front of the main shaft 13 and located above the sliding groove 131, and the first sun gear 36 and the second sun gear The 37 series can be respectively engaged with the first planetary gears 34 and the second planetary gears 35, and the first sun gear 36 and the second sun gear 37 are respectively provided with a plurality of inner bolt slots 361, 371 in the central collar. .

The second shifting unit 40 is disposed on the main shaft 13 of the hub unit 10 and located in front of the first shifting unit 30. The second shifting unit 40 includes a second ring gear 41 and three third planetary gears 42. a third sun gear 43 is formed in a cylindrical shape and extends rearwardly to form a planetary arm 411. A ring groove 4111 is disposed around the inner side of the planetary arm 411 and is located at the ring. A ring tooth surface 4112 behind the spine groove 4111, and a front end of the second ring gear 41 are annularly formed to form a locking portion 412 which is radially convex, and the third locking portion is disposed around the locking portion 412. 413, the two third clutches 413 are unidirectional pawl clutches, and the second ring gears 41 are sleeved and coupled to the main shaft 13 , and the ring gear slots 4111 are correspondingly engaged with the first shifting unit 30 . The second clutch 331 and the ring gear surface 4112 are correspondingly engaged with the outer circumference of each of the second planetary gears 35. The three third planetary gears 42 are disposed on the planetary arm 411 of the second ring gear 41 and the locking portion 412. And each of the third planetary gears 42 is rotatable and equally spaced around the first The outer peripheral surface of the ring gear 41, the third sun gear 43 is sleeved on the main shaft 13 and located above the sliding groove 131, and the third sun gear 43 is correspondingly engaged with each of the third planetary gears 42. A plurality of inner bolt slots 431 are provided in the center ring.

The speed regulating mechanism 14 of the hub unit 10 can be front and rear of the speed control slider 142 The corresponding convex teeth 1421 are correspondingly abutted against the first sun gear 36, the second sun gear 37 of the first shifting unit 30 or the sun gear 42 of the second shifting unit 40 or not, thereby making the first The shifting unit 30 or the second shifting unit 40 produces different shifting effects.

The differential unit 50 is disposed inside the hub unit 10 and surrounds the outer periphery of the first shifting unit 30 and the second shifting unit 40, and includes a ring sleeve 51 and three planetary gears 52. The ring The sleeve 51 has an elongated cylindrical shape and is formed in a class shape on the inner peripheral wall, and is provided with a ring tooth surface 511 corresponding to each of the third planetary gears 42 of the second shifting unit 40, and is provided with a corresponding The ring sleeves 512 of the two third clutches 413 are sleeved on the outer circumferences of the first shifting unit 30 and the second shifting unit 40, and the ring tooth surface 511 and the ring are The spine slot 512 is correspondingly connected to each of the third planetary gears 42 and the two third clutches 413 of the second shifting unit 40, and the planetary gears 52 are rotatably and equally spaced at the rear end of the ring sleeve 51, and the The differential unit 50 is correspondingly engaged with the outer ring gear 322 of the first ring gear 32 by the planetary gears 52. The differential unit 50 can transmit the first shifting unit 30 and the second shifting unit 40. After the rotational component forces are merged, the rotational component is transmitted to the hub unit by the planetary gears 52. The housing 11 of 10 drives the housing 11 to rotate.

As shown in FIG. 1 , the present invention is capable of transmitting power to the first shifting unit 30 by the transmission unit 20, and the different speed positions are switched by the adjustment of the speed regulating mechanism 14 to generate different speed differences. After the two shifting units 40 are diverted, the power is collected into the differential unit 50 and synthesized into the component after the shifting, and finally transmitted to the hub unit 10. The manner of switching the gears is as shown in FIG. 2 to FIG. 9 : As shown in FIG. 2 , it is a schematic diagram of the power flow direction of the first gear of the present invention, which is used to pull and adjust the speed control slide bar 142 of the speed control mechanism 14 to adjust the convex teeth 1421 of the speed control slide bar 142 to the same. The first sun gear 36 is fixed by the pin groove 361 of the first sun gear 36, causing the first ring gear 32 to mesh with the first planetary gears 34 and the first sun gear 36 to generate a shift speed, and simultaneously The speed regulating ring 31 is branched and generated in the split flow 1 and the split flow 2; therefore, when the power is input from the first planetary arm 33 and outputted by the first ring gear 32, the speed increase unit acts to cause the first ring The angular velocity of the gear 32 is greater than the angular velocity of the first planetary arm 33. Therefore, the first ring gear 32 and the first clutch 311 are over-speeded without being mutually engaged, and the power will be shifted by the first ring gear 32. The planetary gears 52 of the differential unit 50 that are stationary are rotated to transmit power to the differential unit 50; at the same time, the flow 2 is split because the speed control slider 142 does not abut the second sun gear 37 and the third sun gear 43, thus power directly through the first planetary arm 33 The clutch 331 is engaged and transmitted to the second ring gear 41, and is engaged by the two third clutches 413 of the second ring gear 41 to the ring sleeve 51, and the planetary gears 52 of the differential unit 50 are The split 1 and the split 2 generate a merged flow, and the drive 11 drives the outer casing 11 of the hub unit 10 to rotate.

As shown in FIG. 3 , it is a schematic diagram of the power flow direction of the second gear of the present invention, and the second gear is a direct drive gear, which is continuously pulled backward to adjust the speed control slider 142 of the speed governing mechanism 14 in the first gear. The speed adjusting slider 142 is not abutted against any sun gear, so that the first shifting unit 30 and the second shifting unit 40 are idling, and the power is transmitted to the speed regulating ring 31 and directly transmitted by the first clutch 311. a first ring gear 32 and driving the planetary gears 52 of the differential unit 50 Then, the outer casing 11 of the hub unit 10 is rotated.

As shown in FIG. 4 , it is a schematic diagram of the power flow direction of the third gear of the present invention, which is further pulled backward to adjust the speed control slide 142 of the speed control mechanism 14 in the second gear, so that the speed control slide 142 is simultaneously The first sun gear 36 and the second sun gear 37 of the first shifting unit 30 are fixed, and the third sun gear 43 is idling, and the shunt 1 and the shunt 2 are generated at the speed regulating ring 31, and the shunt 1 is the first The power flow direction of the sun gear 36 is the same as the power flow direction of the first gear, so it will not be described; the power flow direction of the split flow 2 flows into the first planetary arm 33 from the speed control ring 31, and the second sun gear 37 The pinch slot 371 is abutted by the protruding teeth 1421 of the speed regulating slider 142, so that the second sun gear 37, the second planet gears 35 and the planet arms 411 of the second ring gear 41 are engaged by the action. The speed increasing unit acts, the angular velocity of the second ring gear 41 is greater than the angular velocity of the first planetary arm 33 to cause an overspeed action, and the second clutch 331 is disengaged from the ring ratchet groove 4111 of the second ring gear 41 without causing a clamping. Effect, so the power continues through the two of the second ring gears 41 Three clutches 413 to pass the differential unit 50 of the ring sleeve 51, and 52 in the differential unit 50 to dispose of the third planetary gear 2 produces split stream and a junction, and then drives the hub unit 10 of the housing 11 is rotated.

As shown in FIG. 5 , it is a schematic diagram of the power flow direction of the fourth gear of the present invention. The third gear is continuously pulled backward to adjust the speed control slide 142 of the speed control mechanism 14 , so that the speed control slide 142 is simultaneously The second sun gear 37 of the first shifting unit 30 is fixed, and the first sun gear 36 and the third sun gear 43 are idly rotated, and the shunting ring 31 is shunted to generate the shunt 1 and the shunt 2, and the shunt 1 flows directly. The differential unit 50, such as the power flow of the second gear, the power flow of the split 2 is like the third gear, and the first planetary arm 33 passes through each of the second planetary gears. The wheel 35 is transmitted to the second ring gear 41, and the second ring gear 41 is merged at the differential unit 50 via the two third clutches 413, and therefore will not be described in detail.

As shown in FIG. 6 , it is a schematic diagram of the power flow direction of the fifth gear of the present invention, which is further pulled backward to adjust the speed control slide bar 142 of the speed control mechanism 14 in the fourth gear, so that the speed control slide bar 142 is simultaneously Fixing the first sun gear 36 of the first shifting unit 30 and the third sun gear 43 of the second shifting unit 40, the second sun gear 37 is idly rotated, and the shunting ring 31 is shunted to generate the shunt 1 and Split 2, the power flow of the split 1 is like the first gear and the third gear, so it will not be described in detail; the power flow of the split 2 is clamped by the first planetary arm 33 to the second ring by the second clutch 331 The planetary arm 411 of the gear 41 is actuated. Since the bolt groove 431 of the third sun gear 43 is abutted by the convex tooth 1421 of the speed control slider 142, the third sun gear 43 and the third planetary gear 42 are The ring tooth surface 511 of the ring sleeve 51 is engaged, and the power is transmitted from the ring sleeve 51 to the planetary gears 52 of the differential unit 50 to merge with the power of the shunt 1 , and then the hub unit 10 is driven. The outer casing 11 rotates.

As shown in FIG. 7 , it is a schematic diagram of the power flow direction of the sixth gear of the present invention, which is further pulled backward to adjust the speed control slide bar 142 of the speed control mechanism 14 in the fifth gear, so that the speed control slide bar 142 is fixed. The third sun gear 43 of the second shifting unit 40 causes the first sun gear 36 and the second sun gear 37 to form an idle rotation, and the split speed of the speed regulating ring 31 is generated by the split 1 and the split 2, and the power of the split 1 is generated. The flow direction is like the second gear, and the power flow of the split flow 2 is like the fifth gear. Finally, the assembly flows to the planetary gears 52 of the differential unit 50, and then the outer casing 11 of the hub unit 10 is rotated, so it will not be described in detail.

As shown in FIG. 8 , it is a schematic diagram of the power flow direction of the seventh gear of the present invention. In the sixth gear, the speed adjusting slider 142 of the speed adjusting mechanism 14 is continuously pulled backward, so that the speed adjusting slider 142 simultaneously fixes the first sun gear 36 and the second sun gear 37 of the first shifting unit 30. And the third sun gear 43 of the second shifting unit 40 is branched and generated in the splitter 1 and the splitter 2, and the power flow of the split 1 is like the first gear; the power flow of the split 2 is due to the second sun. The gear 37 and the third sun gear 43 are both fixed by the speed control slider 142, so that the second sun gear 37 and the second planetary gears 35 mesh with the ring tooth surface 4112 of the second ring gear 41, The third sun gear 43 and the third planetary gears 42 are meshed with the ring tooth surface 511 of the ring sleeve 51, and the power is transmitted from the first planet arm 33 directly to the second ring via the second planet gears 35. The gear 41 is further collected by the second ring gear 41 via the ring sleeve 51, and merges with the planetary gears 52 of the differential unit 50, and then drives the outer casing 11 of the hub unit 10 to rotate.

As shown in FIG. 9 , it is a schematic diagram of the power flow direction of the eighth gear of the present invention, which is further pulled backward to adjust the speed control slide 142 of the speed control mechanism 14 in the seventh gear, so that the speed control slide 142 is simultaneously The second sun gear 37 and the third sun gear 43 of the second shifting unit 40 are fixed, so that the first sun gear 36 of the first shifting unit 30 is idling, and the shunting ring 31 is shunted to generate the shunt 1 and the shunt 2. The power flow of the split 1 is like the second gear, and the power flow of the split 2 is like the seventh gear. Finally, the planetary gears 52 of the differential unit 50 form a merge, and then the outer casing 11 of the hub unit 10 is rotated. Not stated.

The invention assumes that the outer diameter of the hub of the transmission should be at most 140 mm, the minimum number of teeth of the sun gear should be greater than or equal to 20 teeth, and the number of teeth of the planetary gear should be greater than or equal to 18 teeth, if the maximum outer diameter of the assembly space of the planetary gear train is 140mm, when the gear modulus is 1, the maximum number of teeth is limited to 140 teeth, and the number of teeth will be equal to the gear diameter. Through the trial and error method and parameter combination, the diameter and the number of teeth of each gear can be obtained as shown in Table 1:

The invention performs motion analysis, torque analysis, power flow analysis and transmission efficiency analysis by the above design parameters, and obtains the transmission performance analysis results of each gear position as shown in Table 2 below:

The transmission efficiency of this design example can be calculated as an average transmission efficiency of 98.58%. It is a highly efficient bicycle transmission, and at the same time simplifies the complicated design of the existing internal transmission, and is equipped with a translating speed control slider design to make the shifting speed. The process is easier.

The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any one of ordinary skill in the art can use the present invention without departing from the technical features of the present invention. Equivalent embodiments of the local changes or modifications made by the disclosed technology are still within the scope of the technical features of the present invention.

10‧‧‧Wheel unit

11‧‧‧Shell

111‧‧‧ internal tooth surface

12‧‧‧ side cover

13‧‧‧ Spindle

131‧‧‧Sliding trough

14‧‧‧Speed governing mechanism

141‧‧‧Compressed spring

142‧‧‧Speed slider

1421‧‧‧ convex teeth

143‧‧‧ lever

144‧‧‧ stretching spring

20‧‧‧Transmission unit

21‧‧‧Sprocket seat

22‧‧‧Chassis

30‧‧‧First shifting unit

31‧‧‧Speed ring

311‧‧‧First clutch

312‧‧‧ meshing end

32‧‧‧First ring gear

321‧‧‧With holes

322‧‧‧ outer ring teeth

323‧‧‧ Inner ring teeth

33‧‧‧First Planetary Arm

331‧‧‧Second clutch

34‧‧‧First planetary gear

35‧‧‧Second planetary gear

36‧‧‧First sun gear

37‧‧‧second sun gear

361, 371‧‧‧

40‧‧‧Second shifting unit

41‧‧‧second ring gear

411‧‧‧ Planetary Arm

4111‧‧‧ ring spine

4112‧‧‧ring tooth surface

412‧‧‧Card Department

413‧‧‧ third clutch

42‧‧‧ Third planetary gear

43‧‧‧ Third sun gear

431‧‧‧Internal slot

50‧‧‧Differential unit

51‧‧‧ ring sleeve

511‧‧‧ ring tooth surface

512‧‧‧ ring spine

52‧‧‧ planetary gear

1 is a schematic cross-sectional view of a preferred embodiment of the present invention.

Figure 2 is a schematic illustration of the power flow direction of the first gear of the preferred embodiment of the present invention.

Figure 3 is a schematic illustration of the power flow direction of the second gear of the preferred embodiment of the present invention.

Figure 4 is a schematic illustration of the power flow direction of the third gear of the preferred embodiment of the present invention.

Fig. 5 is a schematic view showing the power flow direction of the fourth gear of the preferred embodiment of the present invention.

Fig. 6 is a schematic view showing the power flow direction of the fifth gear of the preferred embodiment of the present invention.

Fig. 7 is a schematic view showing the power flow direction of the sixth gear of the preferred embodiment of the present invention.

Figure 8 is a schematic view showing the power flow direction of the seventh gear of the preferred embodiment of the present invention.

Figure 9 is a schematic illustration of the power flow direction of the eighth gear of the preferred embodiment of the present invention.

10‧‧‧Wheel unit

11‧‧‧Shell

111‧‧‧ internal tooth surface

12‧‧‧ side cover

13‧‧‧ Spindle

131‧‧‧Sliding trough

14‧‧‧Speed governing mechanism

141‧‧‧Compressed spring

142‧‧‧Speed slider

1421‧‧‧ convex teeth

143‧‧‧ lever

144‧‧‧ stretching spring

20‧‧‧Transmission unit

21‧‧‧Sprocket seat

22‧‧‧Chassis

30‧‧‧First shifting unit

31‧‧‧Speed ring

311‧‧‧First clutch

312‧‧‧ meshing end

32‧‧‧First ring gear

321‧‧‧With holes

322‧‧‧ outer ring teeth

323‧‧‧ Inner ring teeth

33‧‧‧First Planetary Arm

331‧‧‧Second clutch

34‧‧‧First planetary gear

35‧‧‧Second planetary gear

36‧‧‧First sun gear

37‧‧‧second sun gear

361, 371‧‧‧

40‧‧‧Second shifting unit

41‧‧‧second ring gear

411‧‧‧ Planetary Arm

4111‧‧‧ ring spine

4112‧‧‧ring tooth surface

412‧‧‧Card Department

413‧‧‧ third clutch

42‧‧‧ Third planetary gear

43‧‧‧ Third sun gear

431‧‧‧Internal slot

50‧‧‧Differential unit

51‧‧‧ ring sleeve

511‧‧‧ ring tooth surface

512‧‧‧ ring spine

52‧‧‧ planetary gear

Claims (2)

The invention relates to a bicycle eight-speed internal transmission, comprising: a hub unit, comprising a cylindrical casing, two side covers respectively coupled to the two sides of the casing, an axially piercing the casing and fixed to the two sides a main shaft of the cover and a speed control mechanism slidably disposed inside the main shaft, the speed control mechanism includes a speed control slide rod, which is slidable along the axial direction of the main shaft, and is provided with a plurality of protrusions The convex teeth of different intervals, each convex tooth protrudes from the main axis, and the number of convex teeth of each convex tooth is twelve, and the optimal design width is 3 mm, and the two ends of each convex tooth need to leave 0.5 mm. a transmission unit fixed to one side of the hub unit; a first shifting unit coupled to the main shaft of the hub unit and coupled to the transmission unit, the first shifting unit includes a speed control ring, a first ring gear, a first planetary arm, a plurality of first planetary gears, a plurality of second planetary gears, a first sun gear and a second sun gear, the speed control ring sleeve On the main shaft and connected to the transmission unit, the first ring gear Nested on the outer circumference of the speed control ring, the first planetary arm is connected to the outer circumference of the speed control ring and located in front of the first ring gear, the plurality of first planetary gears and the plurality of second planetary gear trains The first and second planetary gears are respectively disposed at equal intervals on the outer circumference of the first planetary arm, and the first sun gear and the second sun gear are separately sleeved. The first sun gear can be correspondingly engaged with each of the first planet gears, or the second sun gear can be correspondingly engaged with each other by being coupled to the outer circumference of the main shaft and the speed control mechanism by adjusting the adjustment mechanism. a second planetary gear, the first ring gear is rotatable and selectively connectable to the speed control ring or the first planetary gear; a second shifting unit is coupled to the main shaft of the hub unit and coupled to the first shifting unit, and includes a second ring gear, a plurality of third planetary gears and a third sun gear, the first a second ring gear is sleeved on the main shaft, and is rotatably and selectively connected to the planetary arm or the second planetary gear of the first shifting unit, and each third planetary gear is equidistant ring is disposed on the second ring gear The third sun gear system sleeve is coupled to the outer circumference of the main shaft and the speed control mechanism, and can be adjusted by the adjustment mechanism, so that the third sun gear can be correspondingly engaged with each of the third planetary gears; The speed unit includes a ring sleeve and a plurality of planetary gears, the ring sleeve is rotatably sleeved on the main shaft, and surrounds the first shifting unit and the outer periphery of the second shifting unit, and the ring The sleeve is selectively connected to the second ring gear or the third planetary gears of the second shifting unit, and the planetary gear trains are equally disposed around the rear end of the differential unit and are engaged with the first shifting unit. Ring tooth And the inner shell of the hub unit. The bicycle eight-speed internal transmission according to claim 1, wherein the speed control ring of the first shifting unit can be clamped to the first ring gear by a first clutch, and the second planetary arm can be engaged with the second clutch The second ring gear, the second ring gear can be clamped to the ring sleeve by a third clutch, and the first, second, and third clutches are all one-way pawl clutches.