JPH06183388A - Power transmission part cover device for front-rear wheel drive type bicycle - Google Patents

Abstract

PURPOSE:To prevent the bite of foreign matter into gear sets with simple constitution in the case of driving the front and rear wheels of a bicycle simultaneously using the gear sets so as to prevent the gear sets from being damaged and to improve outward appearance of the bicycle. CONSTITUTION:A front wheel 5 and a rear wheel 9 are respectively supported by axles 4, 8 in relation to a body frame 2. A flexible power transmission shaft 16 is interposed between the front wheel 5 and the rear wheel 9, and the front and rear ends of this transmission shaft 16 are interlockingly connected to the corresponding front and rear wheels 5, 9 respectively by gear sets 17, 18, so that driving force supplied to the rear wheel 9 from a rider is partially transmitted to the front wheel 5 through the transmission shaft 16 and both gear sets 17, 18. Cover bodies 56, 106 are provided to cover the gear sets 17, 18, and these cover bodies 56, 106 are supported at the axles 4, 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a flexible power transmission shaft and a pair of front and rear gears to transmit a part of the driving force applied from the occupant to the rear wheels to the front wheels for driving. The present invention relates to a power transmission unit cover device for a front-rear wheel drive bicycle.

[0002]

2. Description of the Related Art Conventionally, the above-mentioned bicycle has a U.S. Pat.
There is one disclosed in Japanese Patent No. 04258. According to this, the front wheel and the rear wheel are supported by the axle with respect to the body frame. A flexible power transmission shaft is interposed between the front wheel and the rear wheel, and front and rear ends of the transmission shaft and the corresponding front and rear wheels are interlockingly connected to each other by a gear set. . Then, a part of the driving force applied from the occupant to the rear wheels is transmitted to the front wheels via the transmission shaft and both gear sets.

[0003]

By the way, according to the above-mentioned conventional structure, the gear set is exposed to the outside of the vehicle.
There is a possibility that pebbles that are flipped up during traveling and foreign matter such as grass on the road surface may easily get caught in the gear set and damage the gear set. Therefore, in order to prevent this, it is conceivable to provide a cover body that covers the gear set, but if the cover body is simply provided, a support tool for supporting the cover body on the vehicle body frame side is required. May be complicated. In addition, the above gear set is easily visible in appearance, which causes a deterioration in the appearance of the bicycle.

[0004]

SUMMARY OF THE INVENTION The present invention has been made by paying attention to the above circumstances. When the front and rear wheels of a bicycle are driven together by using a gear set, the foreign matter is caught in the gear set. The purpose of the present invention is to prevent the gear set from being damaged by a simple structure, prevent the gear set from being damaged, and improve the appearance of the bicycle.

[0005]

To achieve the above object, the present invention is characterized in that the front wheel and the rear wheel are supported by the axle on the body frame, respectively, and the flexible frame is provided between the front wheel and the rear wheel. A power transmission shaft, and the front and rear ends of this transmission shaft and the corresponding front and rear wheels are interlockingly connected to each other by a gear set, so that the driving force given to the rear wheel by the occupant. In the case where a part of the above is transmitted to the front wheels through the transmission shaft and both gear sets, a cover body that covers the gear set is provided and the cover body is supported by the axle.

[0006]

[Operation] The operation of the above configuration is as follows. The front wheels 5 and the rear wheels 9 are attached to the vehicle body frame 2 by axles 4 and 8 respectively.
The flexible power transmission shaft 16 is interposed between the front wheel 5 and the rear wheel 9, and the front and rear ends of the transmission shaft 16 and the front and rear wheels 5 and 9 corresponding thereto are provided. Gears 17 and 18 are interlockingly connected to each other, and a part of the driving force given to the rear wheel 9 from the occupant is transmitted to the front wheel 5 via the transmission shaft 16 and both gear sets 17 and 18. In the front and rear wheel drive type bicycle 1, the gear sets 17, 18
Covers 56 and 106 for covering the are provided.

Therefore, the cover bodies 56 and 106 prevent foreign matter from trying to be caught in the gear sets 17 and 18 while the bicycle 1 is running. Moreover, the cover bodies 56 and 106 are supported by the axles 4 and 8. For this reason, the axles 4 and 8 provided for supporting the front wheels 5 and the rear wheels 9 of the bicycle 1 are not covered by the cover body 5.
It will be effectively used for supporting 6,106.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIGS. 1 to 7 show a first embodiment.
In FIG. 1, reference numeral 1 is a bicycle, and an arrow Fr in the drawing indicates the front side thereof. The left and right described below means the direction toward the front. The bicycle 1 has a body frame 2, and a front fork 3 is rotatably supported on the front portion of the body frame 2. A front wheel 5 is rotatably supported by an axle 4 on the lower end of the front fork 3, and a bar-type handle 6 is attached to the upper end of the front fork 3 above.

A rear wheel 9 is rotatably supported by an axle 8 on the rear portion of the vehicle body frame 2. A front chain wheel 10 is rotatably supported on the lower portion of the vehicle body frame 2 in the front-rear midway portion so as to be rotatable about the left-right axis. On the other hand, a rear chain wheel 11 is rotatably supported around the axis of the axle 8 for the rear wheel 9, so that both the wheels 1
A chain 12 is wound around 0 and 11. Also,
Left and right pedals 13, 13 that rotate together with the front chain wheel 10 are provided. A seat 15 for seating an occupant is attached to the upper part of the front and rear midway portion of the vehicle body frame 2.

A flexible power transmission shaft 16 is interposed between the front wheel 5 and the rear wheel 9, and a front end of the transmission shaft 16 and the front wheel 5 are interlockingly connected by a gear set 17. Further, the rear end of the transmission shaft 16 and the rear wheel 9 are the same as those of the gear set 1 in the above.
8 are interlockingly connected to each other.

When the occupant on the seat 15 pushes the pedals 13,
When 13 is stepped on and rotated (arrow A in FIG. 1), the driving force from the occupant is applied to the rear wheels 9 via the front chain wheel 10, the chain 12, and the rear chain wheel 11 which rotate accordingly. The bicycle 1 is rotated (arrow B in FIG. 1) and the bicycle 1 runs.

At this time, a part of the driving force applied to the rear wheel 9 is transmitted to the front wheel 5 via the gear set 18, the transmission shaft 16 and the gear set 17, and the front wheel 5 is transferred to the rear wheel 5. It is rotated at the same speed as the wheel 9 (arrow C in FIG. 1). That is,
As a result, both the front wheels 5 and the rear wheels 9 are driven, and traveling suitable for off-road can be obtained.

The body frame 2 will be described in more detail with reference to FIG. The body frame 2 has a head pipe 20 which supports the front fork 3 at a front portion thereof. A top pipe 21 extends substantially horizontally from the upper portion of the head pipe 20 toward the rear. Also,
Same as above, a down pipe 22 extends from the lower part of the head pipe 20 toward the lower rear side. Rear ends of the top pipe 21 and the down pipe 22 are connected to each other by a back stay 23.

The portion where the rear end of the top pipe 21 and the upper end of the back stay 23 are joined is a seat pillar 25, and the seat pillar 25 supports the seat 15. In addition, the portion where the rear end of the down pipe 22 and the lower end of the back stay 23 are joined together is the bottom bracket 2.
6, the front chain wheel 10 and the pedal 13 are supported by the bottom bracket 26 as described above.

A pair of left and right seat stays 27 extends rearward and downward from the seat pillar 25. A pair of left and right chain stays 28 extends substantially horizontally from the bottom bracket 26 toward the rear. The rear ends of the seat stay 27 and the chain stay 28 are connected to each other.

1 to 4, a pair of left and right fork ends 30, 30 is provided at the lower end of the front fork 3.
Each of these fork ends 30 is formed with an inverted U-shaped notch 31 that opens downward.
On the other hand, the axle 4 has a large diameter main shaft 32 located in the middle of the left and right, a left bolt 33 protruding from the left end of the main shaft 32, and a right bolt 3 protruding from the right end of the main shaft 32.
4 and these are provided coaxially.

Then, the base portion of the left bolt 33 is fitted into the notch 31 of the left fork end 30,
The first nut 36 is detachably fastened. The right bolt 34 is fitted in the notch 31 of the right fork end 30 and detachably fastened by the second to fifth nuts 37 to 40, whereby the fork end at the lower end of the front fork 3 is attached. Axle 4 is detachably supported by 30, 30.

The front wheel 5 is composed of a hub 42 rotatably supported by the main shaft 32 of the axle 4, and a tire 45 supported on the hub 42 by spokes 43 and a rim 44. The transmission shaft 16 includes a flexible outer wire 47 and an inner wire 48. The inner wire 48 is fitted into the outer wire 47 and is rotatable within the outer wire 47 about its axis. It is said that.

The gear set 17 is a bevel ring gear 49.
And a bevel pinion 50 that meshes with this. In the screw portion 52 formed on the right side of the hub 42,
The one-way clutch 53 is firmly screwed so as not to loosen. The bevel ring gear 49 is detachably screwed to the one-way clutch 53 by a bolt 54, and the bevel ring gear 49 and the one-way clutch 53 are provided coaxially with the axle 4. The threaded portion 52 is shown as a left-hand thread in the drawing,
It may be a right-hand thread. On the other hand, the bevel pinion 50
Is detachably connected to the front end of the inner wire 48, and the one-way clutch 53 allows transmission of power only from the gear set 17 side to the hub 42 side.

A cover member 56 made of sheet metal is provided to entirely cover the gear set 17 from the right side. The cover body 56 has a disk-shaped first cover 57 that is coaxial with the bevel ring gear 49 and covers the bevel ring gear 49 from the right side. A central hole 57a is formed on the axis of the first cover 57, and the central hole 57a is slightly larger than the outer diameter of the right bolt 34. Then, the center hole 57a is formed in the right bolt 34.
It fits without rattling, and the edge of the center hole 57a is the third
It is fastened between the nut 38 and the fourth nut 39.
Further, the first cover 57 has an annular portion 5 which is bent so as to cover the outer peripheral surface of the bevel ring gear 49 on the outer peripheral portion thereof.
Have eight.

A substantially V-shaped cutout 59 is formed in the upper portion of the first cover 57, and a second cover 60 is provided to close the cutout 59 from the right side. This second
The cover 60 is a second cover body 6 having a channel-shaped cross section.
1 and a pair of outward flanges 62, 62 formed on the edge of the second cover body 61. Each of the outward flanges 62 is detachably screwed to the first cover 57 by a bolt 63. In this case, the outer surface of the second cover body 61 is located closer to the center of the vehicle than the protruding end of the right bolt 34, and the outward flange 62 is provided closer to the center of the vehicle than the fork end 30.

A channel-shaped bracket 65 is removably fitted into the inside of the second cover body 61, and the bracket 65 is detachably screwed to the second cover body 61 with a bolt 66. Both protruding ends of the bracket 65 are fitted into the notches 59, and the bevel pinion 50 is supported at both protruding ends of the bracket 65 by a pair of bearings 67, 68.
With this support, the bevel pinion 50 meshes with the bevel ring gear 49. Further, the bearing 67 includes
The front end of the outer wire 47 is detachably fixed. In the above case, the bevel ring gear 49 is screwed to the hub 42 provided on the shaft center of the axle 4, while the bevel pinion 50 is fitted to the right bolt 34 of the axle 4 and is screwed to the cover body. It is supported by 56. For this reason, the bevel ring gear 49 and the bevel pinion 50 are accurately positioned with respect to each other via the axle 4, so that the bevel ring gear 49 and the bevel pinion 50 are accurately meshed with each other. Also, from this, the bevel pinion 50 is attached to the first cover 57 screwed to the right bolt 34 of the axle 4.
When the second cover 60 assembled with is screwed, the bevel pinion 50 automatically meshes with the bevel ring gear 49 with high accuracy. Therefore, the relative positioning work when the bevel ring gear 49 and the bevel pinion 50 are assembled can be extremely easily performed.

The inner wire 48 shown in FIG.
And the bevel pinion 5 when rotated as shown by arrow D in FIG.
0, the bevel ring gear 49, and the one-way clutch 53, the front wheels 5 rotate as indicated by an arrow C in FIGS. 1 to 3. In this case, the cover body 56 tries to rotate in the opposite direction of the arrow C through the bevel ring gear 49 and the bracket 65 by the reaction force when the front wheel 5 is rotated. Therefore, in order to prevent this reverse rotation, an arm 70 is integrally projectingly provided on the outer peripheral portion of the first cover 57, and the protruding end of this arm 70 is attached to a band 71 attached to the front fork 3 by a bolt 72. It is detachably connected.

In FIGS. 1 and 5 to 7, a pair of left and right fork ends 80, 80 are formed at the joints of the rear ends of the seat stay 27 and the chain stay 28. Is formed with an inverted U-shaped notch 81 that opens downward. On the other hand, the axle 8 for the rear wheel 9 has a large diameter main shaft 82 located in the middle of the left and right sides, a left bolt 83 protruding from the left end of the main shaft 82 and a right end of the main shaft 82. And a right bolt 84, which are coaxially provided.

Then, the base portion of the right bolt 84 is fitted into the notch 81 of the right fork end 80,
The first nut 86 is detachably fastened. Further, the left bolt 83 is fitted into the notch 81 of the left fork end 80 and is detachably fastened with the second to fifth nuts 87 to 90, whereby the axle 8 is attached to the fork ends 80, 80. Is detachably supported.

The rear wheel 9 is composed of a hub 92 rotatably supported by the main shaft 82 of the axle 8, and a tire 95 supported on the hub 92 by spokes 93 and a rim 94.

The gear set 18 includes a bevel ring gear 99.
And a bevel pinion 100 that meshes with this. Threaded portion 102 formed on the right side of the hub 92
Further, the bevel ring gear 99 is firmly screwed so as not to loosen, and the bevel ring gear 99 is provided coaxially with the axle 8. Although the threaded portion 102 is shown as a left-hand thread in the drawings, it may be a right-handed thread. On the other hand, the bevel pinion 100 is detachably connected to the rear end of the inner wire 48.

A cover body 106 made of sheet metal is provided which entirely covers the gear set 17 from the left side. The cover body 106 has a disk-shaped first cover 107 that is coaxial with the bevel ring gear 99 and covers the bevel ring gear 99 from the left side. A central hole 107a is formed on the axis of the first cover 107.
7a has a size slightly larger than the outer diameter of the left bolt 83. Then, the center hole 107a is fitted into the left bolt 83 without rattling, and
The edge of 7a is fastened between the third nut 88 and the fourth nut 89. Further, the first cover 107 has an annular portion 108 on its outer peripheral portion that is bent so as to cover the outer peripheral surface of the bevel ring gear 99.

A substantially V-shaped notch 109 is formed in the upper portion of the first cover 107, and a second cover 110 is provided to close the notch 109 from the right side.
The second cover 110 is composed of a second cover body 111 having a channel-shaped cross section, and a pair of outward flanges 112, 112 formed on the edge of the second cover body 111. Each of the outward flanges 112 is detachably screwed to the first cover 107 by a bolt 113. In this case, the second cover body 11
The outer surface of 1 is located closer to the center of the vehicle than the protruding end of the left bolt 83, and the outward flange 112 is provided closer to the center of the vehicle than the fork end 80.

A channel-shaped bracket 115 is removably fitted in the second cover body 111,
The bracket 115 is detachably screwed to the second cover body 111 with a bolt 116.
Both protruding ends of the bracket 115 are provided with the notch 10
9 and the bevel pinion 100 has a pair of bearings 117 and 11 at both projecting ends of the bracket 115.
Both ends are supported by 8, and by this support, the bevel pinion 100 meshes with the bevel ring gear 99 with high precision. The rear end of the outer wire 47 is detachably fixed to the bearing 117. In the above case, the bevel ring gear 99 is screwed to the screw portion 52 provided on the shaft center of the axle 8, while the bevel pinion 100 is fitted to the left bolt 83 of the axle 8 and is screwed to the cover. It is supported by the body 106. Therefore, the bevel ring gear 99 and the bevel pinion 10 are
0 is accurately positioned with respect to each other via the axle 8, so that the bevel ring gear 99 and the bevel pinion 100 are accurately meshed with each other. Further, from this, when the second cover 110 having the bevel pinion 100 assembled is screwed to the first cover 107 screwed to the left bolt 83 of the axle 8, the bevel pinion 100 is automatically attached to the bevel ring gear 99. Will be meshed with high precision. Therefore, the relative positioning work at the time of assembling the bevel ring gear 99 and the bevel pinion 100 can be extremely easily performed.

Then, as described above, the occupant pedals 1
Driving force is applied to the rear wheels 9 through the chains 12 and the rear chain wheels 11 by stepping on 3, 3 and this is shown in FIG.
3 rotates as indicated by arrow B in FIG. 3, the inner wire 48 accordingly rotates through the gear set 18 as indicated by arrow D in FIG. 3, and this driving force is applied to the front wheel 5 side as described above. It is designed to be used. A one-way clutch is provided between the main shaft 82 and the hub 92, and the one-way clutch is installed from the hub 92 side to the main shaft 82.
Allows power transmission only to the side.

In the above case, the cover body 106 tries to rotate in the opposite direction of the arrow C through the bevel ring gear 99 and the bracket 115 by the reaction force when the rear wheel 9 is rotated. Therefore, in order to prevent the reverse rotation, an arm 120 is integrally projectingly provided on the outer peripheral portion of the first cover 107, and a protruding end of the arm 120 is attached to and detached from a band 121 attached to a band 121 by a bolt 122. It is freely connected. In addition, the above-mentioned both gear sets 17, 18
Are isomorphic and large to each other. In addition, both cover bodies 56, 10
6 also have the same shape and the same size, and the parts are commonly used.

1 to 7, the front axle 5 and the rear axle 9 are attached to the fork ends 30 and 80, and the axles 4 and
A procedure for assembling the gear 8, the gear sets 17, 18 and the cover bodies 56, 106 will be described.

First, the hubs 42 and 92 are assembled to the axles 4 and 8 by the second nuts 37 and 87 and the third nuts 38 and 88. Next, the first cover 5 is attached to the axles 4 and 8 above.
7, 107 are assembled with the fourth nuts 39, 89.
Next, the axles 4 and 8 are attached to the fork ends 30 and 80 by the first nuts 36 and 86 and the fifth nuts 40 and 90.

On the other hand, the bevel pinions 50 and 100 are attached to the second covers 60 and 110 by the brackets 65 and 115 and the bolts 66 and 116, and this assembly is attached to the first cover 57 by the bolts 63 and 113. Then, the bevel pinions 50, 100 are automatically and accurately meshed with the bevel ring gears 49, 99 to be assembled. Next, the arms 70 and 120 are attached to the bands 71 and 121.
The assembly is completed by connecting bolts 72, 122 to.

The disassembling procedure of the gear sets 17, 18 and the like may be the reverse of the above procedure. In the assembling procedure, on the front wheel 5 side, even if the axle 4 is attached to the fork end 30 with the second cover 60 attached to the first cover 57, the front fork 3 does not interfere with this assembling. Therefore, this procedure may be used.

On the other hand, on the rear wheel 9 side, when the procedure described above is attempted, the second cover 110 causes the seat stay 27 to move.
Alternatively, since it contacts the chain stay 28, this procedure cannot be taken. Although the above is based on the illustrated example, the second nut 37, the third nut 38, and the second nut 87
The third nut 88 and the third nut 88 may be integrally molded products.

The following drawings show the second to fifth embodiments. In addition, about a structure and an action which each of these Examples and the said Example 1 are mutually common, the same code | symbol is attached | subjected to drawing and the overlapping description is abbreviate | omitted and a different thing is mainly demonstrated. Further, the reference numerals in the parentheses particularly indicate those on the rear wheel 9 side.

(Second Embodiment) FIG. 8 shows a second embodiment. According to this, the nut 12 is attached to the bolt 66 (116).
4 is screwed on and the nut 124 is attached to the bolt 66.
It is fixed to (116) by a retaining pin 125. Bracket 65 for the second cover 60 (110)
(115) are connected by the bolts 66 (116), and the bracket 65 (115) is the same as the nut 1 described above.
Coil spring 126 that elastically biases against 24
Is provided. Then, in the above state, the bevel pinion 50 (100) is accurately meshed with the bevel ring gear 49 (99). The bevel pinion 50 (10
0) and the bevel ring gear 49 (99) are assembled, if there is some error between them, or the bicycle 1 receives an external force during traveling, and the vehicle body frame 2 and the axle 4 (axle 8) are Due to the distortion generated, the bevel pinion 50 (bevel pinion 100) and the bevel ring gear 4
If an error occurs between the 9 (bevel ring gear 99) and the bevel pinion 50 (bevel pinion 100), the bevel pinion 50 (bevel pinion 100) is too deeply engaged with the bevel pinion 50 (bevel pinion 100). May receive a large load from the bevel ring gear 49 (bevel ring gear 99). Then, in this case, the load opposes the spring 126 to push the bevel pinion 50 (bevel pinion 100), whereby the bevel pinion 50 (bevel pinion 100) with respect to the bevel ring gear 49 (bevel ring gear 99). The meshing is maintained with a predetermined accuracy. The spring 126 may be an elastic body made of rubber or the like.

(Third Embodiment) FIGS. 9 and 10 show a third embodiment. According to this, the cover body 106 on the rear wheel 9 side
Outward flange 112 of the second cover body 111 at
Is located outside the seat stay 27 and the chain stay 28. According to this, the second cover main body 111 can be attached to and detached from the first cover 107 without affecting the seat stay 27 and the chain stay 28, that is, this work can be facilitated.

(Fourth Embodiment) FIG. 11 shows a fourth embodiment. According to this, the first cover 107 and the second cover body 111 are integrally formed. In this case, in order to facilitate the assembling of the cover body 106 to the axle 8, the second cover body 111 is not provided between the seat stay 27 and the chain stay 28, but the seat stay 2 described above.
It is located on the rear side of 7. In addition, this configuration has the front wheels 5
It may be applied to the side cover body 56.

(Fifth Embodiment) FIG. 12 shows a fifth embodiment. According to this, the center hole 57a (107a) of the first cover 57 (107) has a hexagonal shape, and the hexagonal portion 128 is formed in the left bolt 33 (83) fitted therein. According to this, since the first cover 57 (107) and the right bolt 34 (left bolt 83) rotate integrally, the arm 70 (120), the band 71 (121), and the bolt 72 (122) are unnecessary. Becomes The above center hole 5
The 7a (107a) and the hexagonal part 128 may be polygons such as squares.

(Sixth Embodiment) FIGS. 13 and 14 show a sixth embodiment.
Is shown. In FIG. 13, the first cover 57 covers only the upper portion of the bevel ring gear 49 from the outside.
In FIG. 14, the first cover 107 covers only the upper front part of the bevel ring gear 99 from the outside.

[0044]

According to the present invention, the front wheel and the rear wheel are respectively supported by the axle on the body frame, and the flexible power transmission shaft is interposed between the front wheel and the rear wheel. , The rear end and the corresponding front and rear wheels are interlockingly connected to each other by a gear set, and a part of the driving force given from the occupant to the rear wheel is partially transmitted through the transmission shaft and both gear sets. In the front-rear-wheel drive type bicycle that is transmitted to the front wheels, a cover body is provided to cover the gear set.

Therefore, the cover body prevents foreign matter from trying to be caught in the gear set while the bicycle is running. Therefore, it is possible to prevent the gear set from being damaged by the above bite. Moreover, the cover body is supported on the axle. Therefore, the axles provided for supporting the front wheels and the rear wheels in the bicycle are effectively used for supporting the cover body, and therefore, the support of the cover body is accordingly simpler. It will be possible. Further, since the gear set is covered with the cover body as described above, it is possible to prevent the gear set from being easily seen in appearance, and thus the appearance of the bicycle is improved.

[Brief description of drawings]

FIG. 1 is an overall left side view of the first embodiment.

FIG. 2 is a right side view of a front wheel side according to the first embodiment.

FIG. 3 is a front cross-sectional view on the front wheel side in the first embodiment.

4 is a sectional view taken along line 4-4 of FIG. 3 in Embodiment 1. FIG.

5 is a partially enlarged view of FIG. 1 in Embodiment 1. FIG.

FIG. 6 is a rear view on the rear wheel side in the first embodiment.

7 is a sectional view taken along line 7-7 of FIG. 6 in Example 1. FIG.

FIG. 8 is a diagram corresponding to FIG. 3 (FIG. 6) in the second embodiment.

FIG. 9 is a diagram corresponding to FIG. 5 in the third embodiment.

FIG. 10 is a diagram corresponding to FIG. 7 in the third embodiment.

FIG. 11 is a diagram corresponding to FIG. 5 in the fourth embodiment.

FIG. 12 is a diagram corresponding to FIG. 3 (FIG. 6) in the fifth embodiment.

FIG. 13 is a diagram corresponding to FIG. 2 in the sixth embodiment.

14 is a diagram corresponding to FIG. 5 in Example 6. FIG.

[Explanation of symbols]

 1 Bicycle 2 Body Frame 4 Axle 5 Front Wheel 8 Axle 9 Rear Wheel 16 Transmission Shaft 17 Gear Set 18 Gear Set 56 Cover Body 57 1st Cover 60 2nd Cover 106 Cover Body

Claims (1)

[Claims] 1. A front wheel and a rear wheel are supported by a vehicle body frame by an axle, respectively, and a flexible power transmission shaft is interposed between the front wheel and the rear wheel. The front wheel and the rear wheel corresponding to the above are linked to each other by a gear set, and a part of the driving force given to the rear wheel by an occupant is transmitted to the front wheel through the transmission shaft and both gear sets. A front / rear wheel drive bicycle power transmission section cover device for a front / rear wheel drive bicycle, wherein a cover body is provided to cover the gear set, and the cover body is supported by the axle.