CN218258573U - Front speed variator of bicycle - Google Patents

Abstract

A front speed-changing device of a bicycle comprises a first sun gear, a second sun gear, a first driven member, a second driven member and a driving member. The driving member can be driven by external force to move to a fifth position and a sixth position; when the driving member moves to the fifth position, the driving member can drive the first driven member to move from a first position to a second position, and at the moment, the first driven member is connected with the first sun gear, so that the first sun gear cannot rotate; when the driving member moves to the sixth position, the driving member drives the second driven member to move from a third position to a fourth position, and at the moment, the second driven member is connected to the second sun gear, so that the second sun gear cannot rotate. The utility model discloses can change transmission efficiency through the mode of actuating that changes sun gear.

Description

Front speed variator of bicycle

Technical Field

The present invention relates to a bicycle, and more particularly to a front derailleur for a bicycle with an internal shifting function.

Background

Generally, the bicycle is adjusted in speed by adjusting the size of the front and rear toothed discs to match different gear ratios, thereby generating different transmission ratios. The so-called gear ratio is the ratio of the number of teeth on the front cog to the number of teeth on the rear cog. For example, if the front toothed disc has 36 teeth and the rear toothed disc has 18 teeth, the gear ratio is 36/18=2. A gear ratio of 2 means that the front gear disc rotates 1 turn and drives the rear gear disc to rotate 2 turns. Since the front cog is driven by the crank and the rear cog drives the rear wheel to rotate, the gear ratio is equal to the transmission ratio in the case of no transmission, so that in the above example, it can be known that 1 rotation of the crank drives the rear wheel to rotate 2 rotations.

In order to allow a rider to adjust the transmission efficiency of the bicycle according to different riding conditions, most bicycles are provided with a transmission. The traditional derailleur accessible itself position change and drive the chain and move to different fluted discs on, because the size difference between the fluted discs, the weight of trampling can consequently change, and reaches the effect of variable speed.

The conventional front chain wheel transmission usually needs to be matched with a plurality of front chain wheels for use, and the chain can move between the front chain wheels with different tooth numbers through the actuation of the front chain wheel transmission. However, the arrangement of a plurality of front chainrings increases the weight of the entire bicycle and requires consideration of the space between the cranks and the frame; in addition, it is not possible to provide a plurality of pulleys simultaneously if it is a belt drive. Therefore, how to develop a transmission that can be used with a single pulley/toothed disc without occupying too much space is one of the objectives to be solved by the developers in the related art.

SUMMERY OF THE UTILITY MODEL

A primary object of the present invention is to provide a front derailleur for a bicycle, which can change transmission efficiency by changing the actuation mode of a sun gear.

To achieve the above object, the present invention discloses a front speed changing device for a bicycle, comprising: a sun gear set having a first sun gear and a second sun gear; the first sun gear and the second sun gear can rotate freely; a driven member capable of rotating along an axial direction; a plurality of planetary gears, which are arranged between the sun gear set and the driven member, can revolve around the sun gear set, and each planetary gear can rotate along an axial direction; each planet gear is provided with a first gear and a second gear, and the first gear and the second gear rotate synchronously; wherein the first plurality of gears are engaged with the first sun gear, and the second plurality of gears are engaged with the second sun gear; a first driven member movable between a first position and a second position; when the first driven piece moves to the first position, the first driven piece leaves the first sun gear, so that the first sun gear can rotate freely; when the first driven part moves to the second position, the first driven part is connected with the first sun gear, so that the first sun gear cannot rotate; a second driven member movable between a third position and a fourth position; when the second driven member moves to the third position, the second driven member leaves the second sun gear, so that the second sun gear can rotate freely; when the second driven member moves to the fourth position, the second driven member is connected to the second sun gear, so that the second sun gear cannot rotate; and a driving member movable to a fifth position and to a sixth position; when the driving member moves to the fifth position, the driving member drives the first driven member to move from the first position to the second position, and the second driven member moves from the fourth position to the third position; when the driving member moves to the sixth position, the driving member drives the second driven member to move from the third position to the fourth position, and the first driven member moves from the second position to the first position.

In one embodiment, the driving member has a plurality of driving protrusions; the first driven part has plural first bumps corresponding to the plural driving bumps; the second driven member has a plurality of second bumps corresponding to the plurality of driving bumps; when the driving member moves to the fifth position, the plurality of driving protrusions abut against the plurality of first protrusions of the first driven member and leave the plurality of second protrusions, so that the first driven member moves to the second position, and the second driven member moves to the third position; when the driving member moves to the sixth position, the driving protrusions abut against the second protrusions of the second driven member and leave the first protrusions, so that the second driven member moves to the fourth position and the first driven member moves to the first position.

In one embodiment, the driving member further has a plurality of receiving slots; when the driving member moves to the fifth position, the plurality of second bumps are accommodated in the plurality of accommodating grooves; when the driving member moves to the sixth position, the plurality of first bumps are accommodated in the plurality of accommodating grooves.

In one embodiment, the driving member is rotationally moved to the fifth position and the sixth position; the plurality of driving lugs are annularly arranged on one side of the driving part; the plurality of first bumps of the first driven member and the plurality of second bumps of the second driven member are also arranged in a ring shape; the first bumps are arranged on a first circumference, and the second bumps are arranged on a second circumference; the diameter of the first circumference is not equal to the diameter of the second circumference.

In one embodiment, the plurality of first bumps and the plurality of second bumps are arranged alternately.

In one embodiment, the device further comprises a first elastic member and a second elastic member; two ends of the first elastic piece respectively prop against the first sun gear and the first driven piece to provide a first elastic force to enable the first driven piece to move from the second position to the first position; two ends of the second elastic element respectively prop against the second sun gear and the second driven element to provide a second elastic force to enable the second driven element to generate a trend of moving from the fourth position to the third position.

In one embodiment, the first follower has a first coupling hole; the bicycle further comprises a fixing piece, one end of the fixing piece is fixed on a frame of the bicycle, and the other end of the fixing piece is provided with a bearing part which extends and protrudes and corresponds to the shape of the first combining hole; at least one part of the bearing part extends into the first combination hole of the first driven part, so that the first driven part cannot rotate relative to the fixed part.

In one embodiment, the second follower has a second combining hole corresponding to the shape of the outer circumference of the first follower; at least one part of the first driven piece extends into the second combination hole of the second driven piece, so that the second driven piece cannot rotate relative to the first driven piece.

In one embodiment, the first sun gear is provided with a first engaged portion; a first embedded part corresponding to the plurality of first embedded parts is arranged on one side of the first driven part close to the first sun gear; when the first driven member moves to the second position, the first engaging portion engages with the first engaged portion, so that the first sun gear cannot rotate relative to the first driven member.

In one embodiment, the second sun gear is provided with a second engaged portion, and one side of the second driven member, which is close to the second sun gear, is provided with a second engaging portion corresponding to the second engaged portion; when the second driven member moves to the fourth position, the second engaging portion engages with the second engaged portion, so that the second sun gear cannot rotate relative to the second driven member.

The utility model provides a preceding speed change gear of bicycle controls the removal of this first follower and this second follower through removing this driving piece, and then adjusts the mode of actuating of this first sun gear and this second sun gear to reach the effect of multistage variable speed. Compare preceding derailleur and need set up a plurality of preceding fluted discs before the tradition, and can't use in belt drive's belt pulley, the utility model discloses can be applicable to the transmission structure of single preceding fluted disc/front pulley, save the cost and improve application range.

The following description will be made in detail with reference to the accompanying drawings, which illustrate preferred embodiments of the present invention according to the purpose and effects thereof.

Drawings

Fig. 1 is an external view schematically illustrating a bicycle according to a preferred embodiment of the present invention.

Fig. 2 is an exploded view of a preferred embodiment of the present invention.

Fig. 3 is an exploded view of some of the components of a preferred embodiment of the invention.

Fig. 4 is a cross-sectional view of a preferred embodiment of the present invention.

Fig. 5 is a partial schematic view of a preferred embodiment of the present invention, showing the first driven member in the first position.

Fig. 6 is a partial schematic view of a preferred embodiment of the present invention, showing the driving member driving the first driven member to move to the second position.

Fig. 7 is a schematic cross-sectional view of a preferred embodiment of the present invention, showing a transmission configuration of the first sun gear, the first gear and the driven member.

Fig. 8 is a partial schematic view of a preferred embodiment of the present invention, showing the second driven member in a third position.

Fig. 9 is a partial schematic view of the driving member driving the second driven member to move to the fourth position according to a preferred embodiment of the present invention.

Fig. 10 is a schematic cross-sectional view of a preferred embodiment of the present invention, showing a transmission configuration of the second sun gear, the second gear, the first gear and the driven member.

Detailed Description

Referring to fig. 1, a preferred embodiment of the present invention provides a bicycle 1 including a frame 2, two wheels 3, a crank device 4, a second driven member 5 and a driving belt 6. The two wheels 3 are pivoted on the front and rear sides of the frame 2. The crank device 4 is pivotally mounted on the frame 2 for generating a torque. The second driven member 5 is provided at a center position of the wheel 3 on the rear side of the frame 2, and is rotatable together with the wheel 3 on the rear side. The transmission belt 6 connects the crank device 4 and the second driven member 5. Therefore, the torque generated by the operation of the crank device 4 can be transmitted to the second driven member 5 through the transmission belt 6, so that the second driven member generates a corresponding driving torque, and the wheel 3 rotates by the driving torque and moves the bicycle 1 forward.

Referring to fig. 2 to 4, the crank device 4 according to a preferred embodiment of the present invention mainly includes: a crank member 10, a driven member 20, a sun gear set 30, a side cover 40, a planetary gear 50 and a transmission 60. Wherein:

the crank member 10 has a base 11, a central shaft 12 and a crank 13. The base 11 is fixed on the frame 2 and cannot move or rotate relative to the frame 2. The base 11 is generally hollow and tubular, and one end of the base is provided with a first positioning portion 110, and the first positioning portion 110 is a circular tenon surrounding the outer wall of the base 11. The central shaft 12 is disposed through the axial inner portion of the base 11, and two ends of the central shaft extend out of the base 11 along two ends of the base 11. Two first bearings (not shown) are disposed between the central shaft 12 and the base 11, so that the central shaft 12 can rotate relative to the base 11. The crank 13 is disposed at one side of the base 11 and can rotate relative to the base 11. The crank 13 has a carrier 14 and an arm 15. The planet carrier 14 is generally disc-shaped, and has a protrusion 140 at the center, and a shaft hole 141 is further disposed at the center of the protrusion 140 for inserting one end of the middle shaft 12 into the shaft hole 141, and a screw 142 is used to fix the middle shaft 12 to the crank 13, so that the crank 13 and the middle shaft 12 can rotate together. The carrier 14 further has a plurality of pillar portions 143 extending along a vertical direction of the carrier 14 and surrounding the protrusion 140. Wherein the column 143 is substantially hollow and has an internal thread on its inner wall. The arm portion 15 extends along the periphery of the planet carrier 14 in a direction away from the planet carrier 14, and a pedal 16 (shown in fig. 1) is disposed at an end of the arm portion away from the planet carrier 14, so that an operator can step on the pedal 16 to drive the crank 13 to rotate relative to the base 11. It should be added that the crank member 10 is generally provided with two cranks 13, respectively disposed at the two ends of the base 11. Since the connection relationship between the crank arm and the base 11 is the same as that between the crank arm and the bottom shaft 12, only one of the crank arms 13 is specifically described in the present embodiment, and the other crank arm 13 can be pushed by itself.

The driven member 20 is substantially annular, is located between the base 11 and the crank 13 of the crank member 10, and can rotate simultaneously with the crank 13. In the present embodiment, the driven member 20 and the second driven member 5 are both belt pulleys, and the transmission belt 6 is a belt corresponding to the belt pulleys, forming a belt transmission system; in another embodiment, the driven member 20 and the second driven member 5 are both a chain plate, and the transmission belt 6 is a chain corresponding to the plurality of chain plates, forming a chain transmission system. The passive component 20 has a plurality of passive teeth 21 with a predetermined number, which are formed on the inner wall surface of the passive component 20; and a predetermined number of a plurality of transmission teeth 22 formed on an outer wall surface of the driven member 20 for engagement with the transmission belt 6.

The sun gear set 30 is disposed in the driven member 20 and includes a first sun gear 31 and a second sun gear 32 disposed side by side. The first sun gear 31 is an annular member having a predetermined number of first sun teeth 310 formed on the outer peripheral surface of the first sun gear 31, and a first fitted portion 311 extending on one side in the axial direction of the first sun gear 31. The second sun gear 32 is also an annular member having a predetermined number of second sun teeth 320 formed on the outer peripheral surface of the second sun gear 32, and a second fitted portion 321 extending on one axial side of the second sun gear 32. The first sun gear 31 is closer to the planet carrier 14 than the second sun gear 32, and in the embodiment, the size/number of teeth of the first sun gear 31 is smaller than that of the second sun gear 32.

The side cover 40 is disposed on one axial side of the driven member 20, so that the driven member 20 is located between the side cover 40 and the crank 13. The side cover 40 is generally ring-shaped, and a hollow ring portion 41 is protruded from one side of the side cover 40, and a plurality of through holes 42 are formed around the ring portion of the side cover 40, corresponding to the plurality of column portions 143 of the planet carrier 14, for allowing a plurality of screws 43 to pass through the plurality of through holes 42 and engage with the plurality of column portions 143, so as to lock the side cover 40 on the crank 13, thereby rotating synchronously with the crank 13. One end of the pillar 143 extends into the axial inner portion of the driven member 20, and the axial direction of the pillar 143 is parallel to the axial direction of the sun gear set 30.

The plurality of planet gears 50 are respectively pivoted on the plurality of pillar portions 143 of the planet carrier 14, and are annularly arranged around the planet carrier 14 with the pillar portions 143 as intervals. Each planetary gear 50 has a first gear 51 and a second gear 52, the first gear 51 has a predetermined number of first teeth 510 formed on the outer peripheral surface of the first gear 51; the second gear 52 has a predetermined number of second teeth 520 formed on the outer peripheral surface of the second gear 52, and the number of the first teeth 510 is greater than the number of the second teeth 520. Wherein the plurality of first gears 51 are respectively meshed with the first sun gear 31 of the sun gear set 30 and the plurality of driven teeth 21 of the driven member 20 without being meshed with the second sun gear 32; the plurality of second gears 52 are meshed with the second sun gear 32 without meshing the first sun gear 31 and the driven member 20. In the present embodiment, the first gear 51 and the second gear 52 are coaxially and side-by-side formed in an integral manner.

In the present embodiment, a plurality of carrier gears 53 are further included. The plurality of carrier gears 53 are respectively pivoted on the plurality of pillar portions 143 of the planet carrier 14 and are staggered with the plurality of planet gears 50, i.e. the planet gears 50 are disposed between any two carrier gears 53, or the carrier gears 53 are disposed between any two planet gears 50. Each of the carrier gears 53 has a predetermined number of carrier teeth 530 formed on an outer circumferential surface of the carrier gear 53. The plurality of carrier teeth 530 of the plurality of carrier gears 53 only engage with the plurality of passive teeth 21 of the passive component 20 and do not engage with the first sun gear 31 and the second sun gear 32. The plurality of supporting gears 53 only provide a supporting force for the driven member 20, and do not affect the transmission relationship of the crank device 4.

The speed changing device 60 has a fixed member 61, a first driven member 62, a second driven member 63, a driving member 64, a first elastic member 65 and a second elastic member 66. The fixing member 61 is a hollow tubular structure, and has a second positioning portion 610 corresponding to the first positioning portion 110 of the base 11 on one side and a protruding supporting portion 611 on the other side. In this embodiment, the second positioning portion 610 is a groove formed on the inner wall surface of the fixing member and having alternate concave and convex portions. Therefore, the fixing member 61 can be engaged with the base 11 through the second positioning portion 610, so that the fixing member 61 cannot rotate relative to the base 11.

The first follower 62 is a hollow ring-shaped member having a first coupling hole 620 penetrating through both axial ends of the first follower 62, and the shape thereof corresponds to the shape of the receiving portion 611. In this embodiment, the first coupling hole 620 and the receiving portion 611 are substantially hexagonal. In another embodiment, the shape of the first coupling hole 620 and the bearing portion 611 can be other non-circular shapes. Therefore, the bearing portion 611 of the fixing member 61 can pass through the first coupling hole 620, so that the first follower 62 is fixed to the fixing member 61. Since the first coupling hole 620 and the supporting portion 611 are hexagonal, the first follower 62 cannot rotate relative to the fixing member 61, and can only move between a first position and a second position along the axial direction of the fixing member 61. The first follower 62 has a plurality of first protrusions 621 arranged in a ring shape on a side away from the first sun gear 31, and a first engaging portion 622 on a side close to the first sun gear 31. The first fitting portion 622 corresponds to the first fitted portion 311 of the first sun gear 31. In this embodiment, the first engaged portion 311 and the first engaging portion 622 are tooth-shaped structures capable of being engaged with each other.

The second follower 63 is a hollow ring-shaped member, and has an outer diameter larger than that of the first follower 62. The second follower 63 has a second coupling hole 630 penetrating both axial ends of the second follower 63, and has a shape corresponding to the shape of the outer periphery of the first follower 62, which is non-circular. Thereby, the second follower 63 can pass through the second combining hole 630 to be fixed on the outer edge of the first follower 62; since the second engaging hole 630 and the outer periphery of the first follower 62 are non-circular, the second follower 63 cannot rotate relative to the first follower 62 and can only move between a third position and a fourth position along the axial direction of the first follower 62. The second follower 63 has a plurality of second protrusions 631 annularly arranged on a side thereof away from the second sun gear 32. In the embodiment, the plurality of first protrusions 621 are arranged on a first circumference (the annular side of the first follower 62), and the plurality of second protrusions 631 are arranged on a second circumference (the annular side of the second follower 63), and the diameter of the first circumference is not equal to the diameter of the second circumference. When the first driven member 62 is connected to the second driven member 63, the plurality of first bumps 621 and the plurality of second bumps 631 are arranged in a staggered manner, i.e., the second bumps 631 are disposed between any two first bumps 621, or the first bumps 621 are disposed between any two second bumps 631. The second follower 63 has a second engaging portion 632 on a side close to the second sun gear 32, corresponding to the second engaged portion 321 of the second sun gear 32. In this embodiment, the second engaged portion 321 and the second engaging portion 632 are tooth-shaped structures that can be engaged with each other.

The driving member 64 is a hollow annular member, and is disposed in the annular portion 41 of the side cover 40 and sleeved outside the fixing member 61. The driving member 64 has a plurality of driving protrusions 641 arranged annularly on a side close to the first driven member 62 and the second driven member 63, and the plurality of driving protrusions 641 correspond to the plurality of first protrusions 621 and the plurality of second protrusions 631. The driving member 64 can be driven by external force to move to a fifth position and a sixth position, and when the driving member 64 moves to the fifth position, the plurality of driving protrusions 641 act on the plurality of first protrusions 621; when the driving member 64 moves to the sixth position, the driving protrusions 641 act on the second protrusions 631. The driving member 64 further has a plurality of receiving slots 642, and each receiving slot 642 is formed between two adjacent driving protrusions 641; when the driving member 64 moves to the fifth position, the plurality of second protrusions 631 are received in the plurality of receiving slots 642; when the driving member 64 moves to the sixth position, the plurality of first protrusions 621 are received in the plurality of receiving slots 642. It should be added that, in the present embodiment, since the driving member 64 is an annular member, the fifth position refers to any position where the plurality of driving protrusions 641 can contact the plurality of first protrusions 621 (a plurality of fifth positions may be generated according to the number of protrusions); the sixth position refers to any position where the plurality of driving bumps 641 can contact the plurality of second bumps 631 (a plurality of sixth positions may be generated according to the number of bumps). In addition, the external force can be driven by a pull wire, an electric drive or other equivalent driving modes.

The first elastic element 65 is disposed between the first follower 62 and the first sun gear 31, and has one end abutting against the first sun gear 31 and the other end abutting against the first follower 62. When the first driven member 62 moves to the second position, the first elastic member 65 is compressed to generate an elastic force acting on one end of the first driven member 62, so that the first driven member 62 tends to move from the second position to the first position.

The second elastic member 66 is disposed between the second follower 63 and the second sun gear 32, and has one end abutting against the second sun gear 32 and the other end abutting against the second follower 63. When the second follower 63 moves to the fourth position, the second elastic member 66 is compressed to generate an elastic force acting on one end of the second follower 63, so that the second follower 63 tends to move from the fourth position to the third position.

The utility model discloses a what form through the combination of above-mentioned each component structure, its actual operation is applied as follows:

the utility model discloses a front derailleur of bicycle provides two kinds of variable speed modes in this embodiment. Referring to fig. 5 and 6, when the driving member 64 is driven by an external force to move to the fifth position, in the present embodiment, the driving member 64 is considered to rotate a first predetermined angle along a rotation direction, and at the same time, the driving protrusions 641 of the driving member 64 also rotate synchronously. Since the plurality of first bumps 621 and the plurality of second bumps 631 are in a staggered relationship, the plurality of driving bumps 641 only contact and push against the plurality of first bumps 621 of the first driven member 62 but not against the plurality of second bumps 631 of the second driven member 63. Thereby, the first driven member 62 is pushed by the plurality of driving protrusions 641 to move from the first position to the second position until the first engaging portion 622 of the first driven member 62 engages with the first engaged portion 311 of the first sun gear 31, and the first elastic member 65 is compressed due to the shortened distance between the first driven member 62 and the first sun gear 31. Meanwhile, since the driving protrusions 641 do not act on the second protrusions 631, the second follower 63 is returned from the fourth position to the third position by the elastic force of the second elastic member 66, so that the second protrusions 631 are accommodated in the receiving slots 642 (as shown in fig. 8). In this state, the first driven member 62 and the first sun gear 31 form a fixed structure, so that the first sun gear 31 cannot be driven by the plurality of planetary gears 50 to rotate; the second follower 63 and the second sun gear 32 form a free structure, so that the second sun gear 32 can be driven by the plurality of planetary gears 50 to rotate. Thus, the crank device 4 is driven in the transmission mode of the first sun gear 31 (fixed end) -the plurality of first gears 51 (input end) -the driven member 20 (output end) as shown in fig. 7 to form a first transmission ratio, which is influenced by the number of the plurality of first sun teeth 310, the plurality of first teeth 510 and the plurality of driven teeth 21. The second sun gear 32 rotates with the plurality of planetary gears 50 without participating in transmission.

Referring to fig. 8 and 9, when the driving member 64 is driven by an external force to move to the sixth position, in this embodiment, it can be considered that the driving member 64 rotates a second predetermined angle along the rotation direction, and the plurality of driving protrusions 641 of the driving member 64 also rotate accordingly. Since the plurality of first bumps 621 and the plurality of second bumps 631 are in a staggered relationship, the plurality of driving bumps 641 only push against the plurality of second bumps 631 of the second follower 63 but not against the plurality of first bumps 621 of the first follower 62. Thereby, the second follower 63 is pushed by the plurality of driving protrusions 641 to move from the third position to the fourth position until the second engaging portion 632 of the second follower 63 engages with the second engaged portion 321 of the second sun gear 32, and the second elastic member 66 is compressed due to the shortened distance between the second follower 63 and the second sun gear 32. Meanwhile, since the plurality of driving protrusions 641 do not act on the first protrusions 621, the first driven member 62 is returned from the second position to the first position by the elastic force of the first elastic member 65, so that the plurality of first protrusions 621 are accommodated in the plurality of accommodating grooves 642 (as shown in fig. 5). In this state, the second follower 63 and the second sun gear 32 form a fixed structure, so that the second sun gear 32 cannot be driven by the plurality of planetary gears 50 to rotate; the first driven member 62 and the first sun gear 31 form a free structure, so that the first sun gear 31 can be driven by the plurality of planet gears to rotate. Thus, the crank device 4 will transmit in the transmission mode of the second sun gear 32 (fixed end) -the plurality of second gears 52 (first input end) -the plurality of first gears 51 (second input end) -the driven member 20 (output end) as shown in fig. 10 to generate a second transmission ratio. The second transmission ratio is affected by the number of the second sun gears 320, the second gears 520, the first gears 510 and the driven gears 21. Wherein the second gear ratio is different from the first gear ratio. The first sun gear 31 rotates with the plurality of planetary gears 50 without participating in transmission.

As can be seen from the foregoing description, by changing the position of the driving member 64, the actuation modes of the first sun gear 31 and the second sun gear 32 can be changed, thereby adjusting the transmission mode of the crank device 4. It is to be added that two shift modes are provided in addition to those disclosed in the present embodiment. In another embodiment, the present invention can also provide more variable speed modes by increasing the number of components: for example, the number of gears on each planetary gear is increased to 4, the number of sun gears is increased to 4, and the number of followers is also increased to 4; the shift mode can be increased to 4.

To sum up, the utility model provides a preceding speed change gear of bicycle controls the removal of this first follower 62 and this second follower 63 through removing this driving piece 64, and then adjusts the mode of action of this first sun gear 31 and this second sun gear 32 to reach the effect of multistage variable speed. Compare preceding derailleur and need set up a plurality of preceding fluted discs before the tradition, and can't use in belt drive's belt pulley, the utility model discloses can be applicable to the transmission structure of single preceding fluted disc/front pulley, save the cost and improve application range.

The above description is the preferred embodiment of the present invention and the technical principle applied by the same, and for those skilled in the art, without departing from the spirit and scope of the present invention, any obvious changes such as equivalent transformation, simple replacement, etc. based on the technical solution of the present invention all belong to the protection scope of the present invention.

Claims (10)

1. A front speed changing device of a bicycle, which is arranged on the bicycle, is characterized in that the front speed changing device comprises:

a sun gear set having a first sun gear and a second sun gear; the first sun gear and the second sun gear can rotate freely;

a driven member capable of rotating along an axial direction;

a plurality of planetary gears, which are arranged between the sun gear set and the driven member, can revolve around the sun gear set, and each planetary gear can rotate along an axial direction; each planet gear is provided with a first gear and a second gear, and the first gear and the second gear rotate synchronously; wherein the first plurality of gears are engaged with the first sun gear, and the second plurality of gears are engaged with the second sun gear;

a first driven member movable between a first position and a second position; when the first driven piece moves to the first position, the first driven piece leaves the first sun gear, so that the first sun gear can rotate freely; when the first driven part moves to the second position, the first driven part is connected with the first sun gear, so that the first sun gear cannot rotate;

a second driven member movable between a third position and a fourth position; when the second driven member moves to the third position, the second driven member leaves the second sun gear, so that the second sun gear can rotate freely; when the second driven member moves to the fourth position, the second driven member is connected to the second sun gear, so that the second sun gear cannot rotate; and

a driving member, movable to a fifth position and a sixth position; when the driving member moves to the fifth position, the driving member drives the first driven member to move from the first position to the second position, and the second driven member moves from the fourth position to the third position; when the driving member moves to the sixth position, the driving member drives the second driven member to move from the third position to the fourth position, and the first driven member moves from the second position to the first position.

2. The front derailleur of claim 1, wherein the driving member has a plurality of drive lugs; the first driven part has plural first bumps corresponding to the plural driving bumps; the second driven part has a plurality of second bumps corresponding to the plurality of driving bumps; when the driving member moves to the fifth position, the plurality of driving protrusions abut against the plurality of first protrusions of the first driven member and leave the plurality of second protrusions, so that the first driven member moves to the second position, and the second driven member moves to the third position; when the driving member moves to the sixth position, the plurality of driving protrusions abut against the plurality of second protrusions of the second driven member and leave the plurality of first protrusions, so that the second driven member moves to the fourth position, and the first driven member moves to the first position.

3. The front derailleur of claim 2, wherein the driving member further includes a plurality of receiving slots; when the driving member moves to the fifth position, the plurality of second bumps are accommodated in the plurality of accommodating grooves; when the driving member moves to the sixth position, the plurality of first bumps are accommodated in the plurality of accommodating grooves.

4. The front derailleur of claim 2, wherein the driver member is rotationally movable to the fifth position and the sixth position; the plurality of driving lugs are annularly arranged on one side of the driving part; the plurality of first bumps of the first driven member and the plurality of second bumps of the second driven member are also arranged in a ring shape; the first bumps are arranged on a first circumference, and the second bumps are arranged on a second circumference; the diameter of the first circumference is not equal to the diameter of the second circumference.

5. The front derailleur of claim 2 or claim 4, wherein the first plurality of protrusions and the second plurality of protrusions are staggered.

6. The front derailleur of claim 1, further comprising a first resilient member and a second resilient member; two ends of the first elastic piece respectively prop against the first sun gear and the first driven piece to provide a first elastic force to enable the first driven piece to move from the second position to the first position; two ends of the second elastic element respectively prop against the second sun gear and the second driven element to provide a second elastic force to enable the second driven element to generate a trend of moving from the fourth position to the third position.

7. The front derailleur of claim 1, wherein the first follower has a first engagement aperture; the bicycle further comprises a fixing piece, one end of which is fixed on the bicycle, and the other end of which is provided with a bearing part which extends and protrudes and corresponds to the shape of the first combining hole; at least one part of the bearing part extends into the first combining hole of the first driven part, so that the first driven part cannot rotate relative to the fixed part.

8. The front derailleur of claim 1, wherein the second follower has a second engagement hole corresponding to a shape of an outer periphery of the first follower; at least one part of the first driven piece extends into the second combination hole of the second driven piece, so that the second driven piece cannot rotate relative to the first driven piece.

9. The front derailleur of claim 1, wherein the first sun gear has a first engaged portion; a first embedded part corresponding to the plurality of first embedded parts is arranged on one side of the first driven part close to the first sun gear; when the first driven member moves to the second position, the first engaging portion engages with the first engaged portion, so that the first sun gear cannot rotate relative to the first driven member.

10. The front derailleur of claim 1, wherein the second sun gear has a second engaged portion, and a side of the second follower adjacent to the second sun gear has a second engaging portion corresponding to the second engaged portion; when the second driven member moves to the fourth position, the second engaging portion engages with the second engaged portion, so that the second sun gear cannot rotate relative to the second driven member.

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