CN111169586A

CN111169586A - Bicycle capable of running forwards by respectively pedaling forwards or backwards by left and right pedals

Info

Publication number: CN111169586A
Application number: CN202010128701.9A
Authority: CN
Inventors: 姜立人
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-02-28
Filing date: 2020-02-28
Publication date: 2020-05-19

Abstract

A bicycle with left and right pedals capable of running forwards by pedaling forwards or backwards respectively comprises a frame, front and rear wheels, a middle shaft and a big flywheel, wherein a set of directional rotating device with the same shape and symmetrical structure is respectively installed at two ends of the middle shaft, the directional rotating device comprises an upper shell, a lower shell and a middle shaft sleeve, and further comprises two sets of ratchets and a planetary gear train, the first set of ratchets is an inner ratchet wheel, the second set of ratchets is an outer ratchet wheel, an inner ratchet gear ring of the first set of ratchets, an inner gear ring of the planetary gear train, the upper shell and pedals installed on the upper shell are integrated to form a driving part, and a middle pawl seat, a central sun wheel and the middle shaft sleeve of the planetary gear train are integrated and are installed on the middle shaft of the. The bicycle has a brand-new pedaling mode and a better accelerating function, can increase the riding pleasure, and is a novel bicycle suitable for riding and capable of being accepted by consumers.

Description

Bicycle capable of running forwards by respectively pedaling forwards or backwards by left and right pedals

Technical Field

The invention belongs to the technical field of bicycles, and particularly relates to a bicycle with left and right pedals capable of running forwards by pedaling forwards or backwards respectively.

Background

Firstly, the bicycle is a low-carbon environment-friendly vehicle commonly used in daily life of people, the bicycle can solve the problem of traffic jam and can also exercise the physical quality of people, and in recent years, more and more people participate in the green trip of riding the bicycle, and the bicycle is more and more popular. However, the bicycle rider must pedal the bicycle forward to drive forward. When the bicycle is pedaled backwards, the bicycle is idle or reversed, and can not move forwards.

The applicant filed a related invention patent document from the national intellectual property office in 2019, 10 and 18, and invented the name of an accelerator capable of accelerating a bicycle to run forwards by pedaling backwards (application number 201910991338.0). The technology of the invention has the following defects: 1) the second group of ratchet wheels are inner ratchet wheel, the outer ratchet wheel ring is fixed on the bicycle frame to make it unable to rotate, so that the ratchet wheel rotates clockwise, the middle pawl seat drives two pawls to slip and rotate on the top of the inner ratchet wheel ring, the pawls and the elastic spring are all moving parts, the long-time fast slip and rotation may loosen in the riding process, thus causing riding fault. 2) The technology is only limited to be used for replacing a rear wheel of a bicycle with small flight, has good application effect on a common bicycle, but is not suitable for a speed-changing bicycle, because the speed-changing bicycle needs different chain lengths for changing different speed ratios, and finally the tightness of the chain is automatically adjusted by a tightening mechanism below the speed-changing bicycle.

And the left pedal crutch and the right pedal crutch of the existing bicycle are respectively arranged at the left end and the right end of the same central shaft, are directly linked and are fixed in the directions of 180 degrees, so that the bicycle is too monotonous and stiff, and cannot meet the special skill requirement of a rider and exert the greater advantages of the bicycle.

Disclosure of Invention

The invention mainly provides a new technical scheme aiming at the problems of the second ratchet wheel, the third ratchet wheel and the existing ratchet wheel, and aims to 1) firstly provide a more reasonable outer ratchet wheel and inner ratchet wheel technology to replace the inner ratchet wheel technology of the second ratchet wheel in the original design, thereby reducing the processing difficulty and effectively eliminating the occurrence of faults in the use of the second ratchet wheel. 2) The big flywheel and the small flywheel of the bicycle can only rotate clockwise forever, thereby eliminating the biggest defect that the prior art can not be applied to the speed-changing bicycle.

The bicycle with variable speed is made up of left and right pedals, driven end and directional rotating device, and features that its left and right pedals are respectively driven forward or backward.

The invention is realized by the following technical scheme.

A bicycle with left and right pedals capable of running forwards by pedaling forwards or backwards is mainly realized by changing the related structure of the pedal middle shaft of the original bicycle, the left and right pedal crutches of the existing bicycle are directly linked on the middle shaft, the pedal crutches, the middle shaft and a large flywheel are connected into a whole, when a rider pedals forwards, the large flywheel rotates forwards, and then a chain drives the small flywheel and a rear wheel, so that the bicycle runs forwards. When a rider pedals backwards, the large flywheel rotates backwards, the inner ratchet wheel in the small bicycle flies slips and idles, the bicycle cannot move forwards, and the left pedal crank and the right pedal crank are linked in the direction of 180 degrees, so that the requirement of special skills of the rider cannot be met. The present invention is directed to the above problems, and an object of the present invention is to provide a bicycle in which a large flywheel of the bicycle is rotated forward when a rider pedals forward, and the large flywheel of the bicycle is also rotated forward when pedaling backward, so that the left and right pedals can be independently operated forward or backward, and the left and right pedals can be prevented from being linked with each other

The invention directly disconnects the left pedal crutch and the right pedal crutch of the bicycle from the pedal center shaft, and the left end and the right end of the center shaft are respectively provided with a directional rotating device DR (one end of a right big flywheel) and a directional rotating device DL (one end of a left side) of which the driving ends always rotate clockwise no matter the bicycle rotates clockwise or anticlockwise, and the left pedal crutch and the right pedal crutch are respectively and firmly arranged on the outer circles of the directional rotating devices at the two sides for use, so that the original pedal center shaft matched with the respective center hole (the driven end) of the pedal center shaft and the big flywheel of the bicycle can always keep rotating clockwise forward, and the small flywheel and the rear wheel are driven by a chain to rotate clockwise forward, thereby forming the bicycle of which the left pedal and the right pedal can respectively drive forward or backward pedal to move. The main technical structure of the directional rotating device DL and DR comprises: the upper shell, the lower shell, the middle shaft sleeve, the two groups of ratchet wheels and the middle part are provided with a group of planetary gear trains; the two groups of ratchet wheels are in sliding fit with the planetary gear train through balls, the first group of ratchet wheels are inner ratchet wheel and are composed of an inner ratchet wheel gear ring A, two pawls A and pawl seats A, the pawls A and the pawl seats A are arranged on the periphery of the inner ratchet wheel gear ring A and matched with the inner ratchet wheel gear ring A, and springs are arranged on the back of the pawls A. The second group of ratchet wheels are outer ratchet wheel ratchet wheels, which are composed of an outer ratchet wheel gear ring B, two pawls B and pawl seats B, wherein the two pawls B and the pawl seats B are arranged on the periphery of the outer ratchet wheel gear ring B and matched with the outer ratchet wheel gear ring B, and springs are arranged on the back of the pawls B. The pawl seat B of the second group of ratchet wheels is fixed on the shell, the outer ratchet wheel gear ring B is provided with a plurality of mandrels, the mandrels are respectively provided with planet wheels, and the mandrels and the outer ratchet wheel gear ring B are connected into a whole to form a planet carrier; the planet gear is meshed with an inner gear ring on the inner ratchet gear ring A and a central sun gear on the pawl seat A to form a planet gear train; the pedal crank is connected with the excircle of the inner ratchet gear ring A of the first group of ratchet wheels and the inner gear ring of the planetary gear train into a whole to form an important part, namely a driving end, of the directional rotating device; the pawl seat A of the first group of ratchet wheels is connected with a central sun gear and a middle shaft sleeve of the planetary gear train into a whole to form a main component, namely a passive end, of the directional rotating device;

one end of the middle shaft sleeve is an inner hole which can be tightly matched and connected with a middle shaft of a bicycle, a section of thread is arranged on the excircle of the other end of the middle shaft sleeve, a rear gland with internal threads is arranged on the middle shaft sleeve, and finally a hollow inner thread is used for locking, so that the final assembly of the whole accelerator is completed.

Preferably, the number of the planet wheels of the planetary gear train is 3-4.

Preferably, the number of teeth of each gear in the planetary gear train can be designed according to the rotation ratio required by actual application.

Has the advantages that: the invention directly disconnects the left pedal crutch and the right pedal crutch of the bicycle from the pedal center shaft, and respectively adds a set of directional rotating device DL (left end) and DR (right large flywheel end) of which the driving ends always rotate clockwise no matter the driving ends rotate clockwise or anticlockwise, and respectively and firmly installs the left pedal crutch and the right pedal crutch on the outer circles of the directional rotating devices at the two sides for use, so that the original pedal center shaft matched with the respective center shaft sleeve (driven end) and the large flywheel of the bicycle can always keep rotating clockwise and forwards, thereby forming the bicycle of which the left pedal and the right pedal can respectively drive forwards or backwards.

Drawings

FIG. 1 is a front sectional view of the main structure of the present invention;

FIG. 1a is an enlarged schematic view of the left directional rotation device DL;

FIG. 1b is an enlarged view of the right directional rotation device DR;

3 FIG. 3 2 3 is 3 a 3 cross 3- 3 sectional 3 view 3 taken 3 along 3 line 3 A 3- 3 A 3 of 3 FIG. 3 1 3 b 3 of 3 the 3 present 3 invention 3; 3

FIG. 3 is a cross-sectional view taken along line B-B of FIG. 1B in accordance with the present invention;

FIG. 4 is a cross-sectional view taken along line C-C of FIG. 1b of the present invention;

FIG. 5 is a cross-sectional view taken along line D-D of FIG. 1a in accordance with the present invention;

FIG. 6 is a cross-sectional view taken along line E-E of FIG. 1a in accordance with the present invention;

FIG. 7 is a sectional view taken along line F-F of FIG. 1a of the present invention.

Detailed Description

The invention is described in detail below with reference to the attached drawing figures: referring to fig. 1 (including fig. 1a and 1b) and fig. 2 to 7, firstly, the directional rotating device DR at one end of the right big flywheel is described (the structure of the left directional rotating device DL is the same as that of the left directional rotating device DL, so the description is omitted), the device of the invention comprises an upper shell 1, a lower shell 2, a middle shaft sleeve 3, two groups of ratchets and a planetary gear train arranged in the middle, the two groups of ratchets are in sliding fit with the planetary gear train through balls 15, the first group of ratchets (an inner ratchet ring gear A4, a pawl AK1 and a pawl seat a5) are inner ratchet ratchets and are composed of an inner ratchet ring gear a6, two pawls AK1 and a pawl seat a5 which are arranged on the periphery of the inner ratchet ring gear a and. The second group of ratchet wheels (the outer ratchet wheel gear ring B6, the pawl BK2 and the pawl seat B7) are outer ratchet wheel, and are composed of an outer ratchet wheel gear ring B6, two pawls BK2 and two pawl seats B7 which are arranged on the periphery of the outer ratchet wheel gear ring B6 and matched with the outer ratchet wheel gear ring, and a spring 19 is arranged on the back of the pawl BK 2. The planetary gear train (annulus gear 11, planet gears 10 and central sun gear 12) is formed by the annulus gear 11 on the housing 1, the planet gears 10 on the planet carrier 8 and the central sun gear 12 on the central hub 3. The pawl seat B7 of the second group of ratchet wheels is integrated with the lower shell 2, the outer ratchet wheel gear ring B6 is integrated with the planet carrier 8, a plurality of mandrels 9 are arranged on the planet carrier 8, planet wheels 10 are respectively arranged on the mandrels 9, a section of spline hole 13 is processed on the inner wall of the middle shaft sleeve 3 and is convenient to be installed in a matched mode with the bicycle pedal middle shaft 20, the inner ratchet wheel gear ring A4 of the first ratchet wheel and the inner gear ring 11 in the planetary gear train are integrated with the upper shell 1 to form an active component (input end) of the directional rotating device, the pawl seat A5 of the first ratchet wheel and the central sun wheel 12 are integrated with the middle shaft sleeve 3 to form a passive component (output end) of the directional rotating device, and the spline section 14 is arranged on the outer circle of the shell 1 at the position of the inner ratchet wheel gear ring A. The upper shell 1 and the shaft sleeve 3 are positioned and matched in a sliding way through a first circle of balls 15; the planet carrier 8 and the upper shell 1 are positioned and matched in a sliding mode through the second ring of balls 15, the lower shell 2 and the planet carrier 8 are positioned and matched in a sliding mode through the third ring of balls 15, the rear gland 16 and the lower shell 2 are positioned and matched in a sliding mode through the fourth ring of balls 15, the rear gland 16 is connected with the tail end of the middle shaft sleeve 3 through inner hole threads and used for integrally adjusting the rolling fit clearance between each ring of balls and the track of each ring of balls, the external threads of the locking nut 17 are matched with the internal threads of the rear gland 16, the inner end face of the locking nut is tightly pressed against the end face of the middle shaft sleeve 3, and it is guaranteed that the rear gland 16 is not easy.

First, DR embodiment: the rotation direction of an inner ratchet ring gear A4 of a first group of ratchet wheels (an inner ratchet ring gear A4, a pawl AK1 and a pawl seat A5) in the directional rotation device DR is set to be a form (shown in figure 2) which is propped by the pawl AK1 when rotating clockwise, and the rotation direction of an outer ratchet ring gear B6 of a second group of ratchet wheels (an outer ratchet ring gear B6, a pawl BK2 and a pawl seat B7) is set to be a form (shown in figure 4) which is propped by the pawl BK2 when rotating anticlockwise, and then the directional rotation device is installed on the outer side of a large flywheel 21 of a specially-made right pedal middle axle 20 of a bicycle, is matched with one end of the middle axle 20 by virtue of an inner chain hole 13 (or internal thread) in the center of the directional rotation device DR and is fastened by a nut 23. The bicycle right foot turn 22 is mounted on the external spline shaft 14 of the directional rotation device and fixed firmly. At this time, when a rider pedals the right pedal 22 forwards (pedals clockwise), the inner ratchet gear ring A4 of the first group of ratchets (the inner ratchet gear ring A4, the pawl AK1 and the pawl seat A5) also rotates clockwise, and the two pawls AK1 directly drive the pawl seat A5 to rotate clockwise, because the pawl seat A5 and the middle shaft sleeve 3 are integrated, the middle shaft sleeve 3 is connected with the middle shaft 20, and the large flywheel 21 is also arranged on the middle shaft, the large flywheel 21 of the bicycle rotates clockwise forwards at this time and drives a small flywheel through a chain to drive the rear wheel to push the front wheel to rotate together, so that the bicycle runs forwards. In the transmission process, the planetary gear train (the inner gear ring 11, the planet gears 10 and the central sun gear 12) performs integral clockwise transmission, and all gears do not move mutually. The outer ratchet ring gear B6 of the second group of ratchet wheels (the outer ratchet ring gear B6, the pawls BK2 and the pawl seat B7) rotates clockwise in a slipping mode at the top ends of the two pawls BK2 of the outer pawl seat B7.

When the rider pedals the right pedal backwards (anticlockwise pedaling), the rotation is equal to that the inner ratchet ring gear A4 driving the first group of ratchet wheels (the inner ratchet ring gear A4, the pawl AK1 and the pawl seat A5) and the inner ring gear 11 of the planetary gear train (the inner ring gear 11, the planet gears 10 and the central sun gear 12) rotate anticlockwise, the inner ratchet ring gear A4 slips and rotates on the two pawls AK1, and the acting force drives the planet gears 10(3 and 4) to rotate anticlockwise on the respective mandrels 9 through the anticlockwise rotation of the inner ring gear 12 of the planetary gear train (the inner ring gear 11, the planet gears 10 and the central sun gear 12) (because the planet carrier 8 cannot rotate anticlockwise due to the unidirectional limitation of the pawl BK2 fixed on the pawl seat B7 on the bicycle). The anticlockwise rotation of the planet wheels 10 (3-4) drives the central sun wheel 12 to rotate clockwise, and the central sun wheel 12 and the middle shaft sleeve 3 are connected into a whole, so that the central bicycle shaft 20 and the large bicycle flywheel 21 arranged on the central bicycle shaft are naturally driven to rotate clockwise, and the rear wheel is driven to push the front wheel to rotate clockwise through a chain and a small flywheel, so that the bicycle runs forwards.

Second, DL example: (firstly, it should be noted that the D, E, F direction of the left device is viewed from the opposite direction to the A, B, C direction of the right device, i.e. the bicycle with left view is driven forwards), the rotation direction of the inner ratchet ring gear a4 of the first set of ratchet wheels (the inner ratchet ring gear a4, the pawl AK1 and the pawl seat a5) in the directional rotation device DL is set to be the form that the pawl AK1 is abutted when rotating anticlockwise (as shown in fig. 5), the rotation direction of the outer ratchet ring gear B6 of the second set of ratchet wheels (the outer ratchet ring gear B6, the pawl BK2 and the pawl seat B7) is set to be the form that the pawl BK2 is abutted when rotating clockwise (as shown in fig. 7), then the device is installed on a left pedal middle axle specially made for the bicycle, the inner chain hole 13 (or internal thread) at the center of the device is matched with the middle axle and fastened by the nut 25, and then the lower shell 2 is fixed on the bicycle frame so as to. The bicycle left foot crank 24 is mounted on the outer spline shaft 14 of the device and fixed firmly. At the moment, when a rider pedals left pedal forwards (pedals anticlockwise), the inner ratchet gear ring A4 of the first group of ratchet wheels (the inner ratchet gear ring A4, the pawl AK1 and the pawl seat A5) also rotates anticlockwise, and the two pawls AK1 directly drive the pawl seat A5 to rotate anticlockwise, because the pawl seat A5 and the middle shaft sleeve 3 are integrated, the middle shaft sleeve 3 is connected with the middle shaft, and the large flywheel 21 is also arranged on the middle shaft 20, the large flywheel 21 on the right side of the bicycle rotates forwards and clockwise at the moment and drives a small flywheel through a chain to drive the rear wheel to push the front wheel to rotate together, so that the bicycle runs forwards. In the transmission process, the planetary gear train (the inner gear ring 11, the planet gears 10 and the central sun gear 12) performs integral anticlockwise transmission, and all gears do not move mutually. The outer ratchet ring gear B6 of the second group of ratchet wheels (the outer ratchet ring gear B6, the pawls BK2 and the pawl seat B7) rotates anticlockwise by slipping at the top ends of the two pawls BK2 of the outer pawl seat B7.

When the rider pedals the right pedal backwards (clockwise pedaling), the same is that the inner ratchet ring gear A4 driving the first group of ratchet wheels (the inner ratchet ring gear A4, the pawl AK1 and the pawl seat A5) and the inner gear ring 11 of the planetary gear train (the inner gear ring 11, the planet gears 10 and the central gear 12) rotate clockwise, the inner ratchet ring gear A4 slips clockwise on the two pawls AK1, the acting force drives the planet gears 10(3 and 4) to rotate clockwise on the respective mandrels 9 through the clockwise rotation of the inner gear ring 12 of the planetary gear train (the inner gear ring 11, the planet gears 10 and the central sun gear 12) (because the planet carrier 8 is limited by the pawl BK2 fixed on the pawl seat B7 on the bicycle in a single direction, the frame cannot rotate clockwise). The clockwise rotation of the planet wheels 10 (3-4) drives the central sun wheel 12 to rotate anticlockwise, and the central sun wheel 12 and the middle shaft sleeve 3 are connected into a whole, so that the central bicycle shaft 20 and the large bicycle flywheel 21 mounted on the central bicycle shaft are naturally driven to rotate anticlockwise, and the rear wheel is driven to push the front wheel to rotate anticlockwise (the left side shows that the front wheel rotates anticlockwise) through the chain and the small flywheel, so that the bicycle runs forwards.

After a directional rotating device DR (one end of a right large flywheel) and a directional rotating device DL (one end of a left side) are arranged on a bicycle pedal middle shaft, the bicycle with the left pedal and the right pedal capable of running forwards is formed. The bicycle can be ridden by a cyclist in the conventional self-riding mode, can be ridden by adopting a backward pedaling method by both feet, and can be ridden by adopting a forward pedaling mode by one foot, a backward pedaling mode by the other foot, a forward pedaling mode by both feet in parallel or a backward pedaling mode by both feet in parallel in a more wonderful way, and the bicycle always keeps running forwards no matter what different pedaling modes are adopted by the cyclist

Because the ratio of the number of teeth of the inner ring gear 11 of the planetary gear train in the left directional rotation device DL and the right directional rotation device DR to the number of teeth of the central sun gear 12 is always greater than 1 (as shown in fig. 3 or fig. 6), the bicycle will generate an accelerating motion as long as the backward pedaling action occurs, and the speed ratio is equal to the number of teeth of the inner ring gear 11 divided by the number of teeth of the central sun gear 12, so that the bicycle can still run forward and obtain an accelerating effect when the rider pedals backward; the ratio of the number of teeth of the inner ring gear 11 to the central sun gear 12 in the planetary gear train can be designed according to the requirement of the acceleration ratio.

When the rider pedals forwards, one group of muscles is used, and when the rider pedals backwards, the other group of muscles is used, so that two groups of different muscles are alternately used to do work when necessary, the bicycle runs forwards continuously, and the internal potential of the human body is fully exerted and utilized.

The bicycle is scientific in design and novel in structure, and is a novel bicycle which is suitable for application and can be accepted by consumers.

Claims

1. A bicycle with left and right pedals capable of running forwards respectively or backwards comprises a frame, a tap, a front fork, a front wheel, a rear wheel, pedals on a middle shaft, a big flywheel, a chain and a small flywheel on the rear wheel; the method is characterized in that: a set of directional rotating devices DL and DR are respectively arranged at the left end and the right end of the middle shaft (20); the two sets of directional rotating devices DL and DR have the same shape and symmetrical structure, are respectively and symmetrically positioned at one end of the left side of a center shaft (20) and one end of the center shaft (20) at the outer side of a large flywheel (21) at the right, and respectively and firmly install a left pedal crutch (24) and a right pedal crutch (22) on the outer circles (14) of the directional rotating devices DL and DR at the two sides; the directional rotating device (DL or DR) comprises a middle shaft sleeve (3), an upper shell (1), a planet carrier (8), a lower shell (2), a rear gland (16) and a locking nut (17) matched with the rear gland; two groups of ratchet wheels (A5, K1, A4) and (B6, K2, B7) and a group of planetary gear trains (an inner gear ring 11, a planetary gear 10 and a central sun gear 12) are arranged at the middle rotating part; the upper shell (1) and the middle shaft sleeve (3) are positioned and matched in a sliding mode through a first circle of balls (15); the planet carrier (8) and the upper shell (1) are positioned and matched in a sliding way through a second circle of balls (15); the lower shell (2) and the planet carrier (8) are positioned and matched in a sliding way through a third circle of balls (15); the rear gland (16) and the lower shell (2) are positioned and matched in a sliding way through a fourth circle of ball bearings (15); the rear gland (16) is connected with the tail end of the middle shaft sleeve (3) by inner hole threads simultaneously and used for integrally adjusting the rolling fit clearance between each rolling ball (15) and the track of the rolling ball, and the external threads of the lock nut (17) are matched with the internal threads of the rear gland (16) to enable the inner end surface of the lock nut to be tightly pressed against the end surface of the middle shaft sleeve (3) so as to ensure that the rear gland (16) is not loosened;

the second group of ratchet wheels (B6, K2, B7) are set as external ratchet wheel, the external ratchet ring gear (B6) is connected with the planet carrier (8) in the planetary gear train into a whole, the pawl seat (B7) at the periphery is connected with the lower shell (2) into a whole, the lower shell (2) is fixed on the bicycle frame;

the large flywheel (21) is arranged on a right end middle shaft (20) of a frame center hole (26) through a left-handed thread in the middle of the large flywheel, the right directional rotating Device (DR) is connected with the right end of the middle shaft (20) through a shaft sleeve (3) on the outer side of the large flywheel (21), the left directional rotating Device (DL) is connected with the left end of the middle shaft (20) through a spline section (13) in the shaft sleeve (3),

one end of the middle shaft sleeve (3) is a spline hole (13) matched with a bicycle middle shaft (20), the inner hole at the other end is provided with a section of step (27) which is fixed on the middle shaft (20) by using a nut (23) matched with the middle shaft (20), and the outer circular end of the upper shell (1) is provided with a section of spline (14) which is connected with a pedal crutch (22 or 24).

2. A bicycle capable of being driven forward by left and right pedals respectively by forward or backward pedaling as claimed in claim 1, wherein: the large flywheel (21) is provided as a gear.

3. A bicycle capable of being driven forward by left and right pedals respectively by forward or backward pedaling as claimed in claim 1, wherein: the large flywheel (21) is provided with a single or more than one large flywheel set.

4. A bicycle capable of being driven forward by left and right pedals respectively by forward or backward pedaling as claimed in claim 1, wherein: the middle shaft sleeve (3) is connected with the middle shaft (20) by a spline (13).

5. A bicycle capable of being driven forward by left and right pedals respectively by forward or backward pedaling as claimed in claim 1, wherein: the middle shaft sleeve (3) is in threaded connection or in connection with an inner gear and an outer gear with the middle shaft (20).

6. A bicycle capable of being driven forward by left and right pedals respectively by forward or backward pedaling as claimed in claim 1, wherein: the excircle end (14) of the upper shell (1) is connected with a pedal crutch (22 or 24) by adopting thread connection and card-to-board connection.

7. A bicycle capable of being driven forward by left and right pedals respectively by forward or backward pedaling as claimed in claim 1, wherein: the outer circle of the upper shell is provided with a gear.

8. A bicycle capable of being driven forward by left and right pedals respectively pedaling forward and backward according to claim 1 or 7, wherein: the pedal crutch is provided with a pedal rack which moves up and down and is meshed with the gear on the excircle of the upper shell.