CN201745699U

CN201745699U - Foldable foot-operated vehicle

Info

Publication number: CN201745699U
Application number: CN201020046045XU
Authority: CN
Inventors: 史真亮
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-01-08
Filing date: 2010-01-08
Publication date: 2011-02-16
Anticipated expiration: 2020-01-08

Abstract

The utility model discloses a foldable two-wheel foot-operated vehicle, the front wheel of which is a steering wheel and can greatly improve the travelling trafficability characteristic of the foot-operated vehicle compared with a back wheel and the back wheel of which is a driving wheel, can reduce the size of the entire vehicle compared with the front wheel, allows a user to operate the vehicle upwards and downwards freely and is always directly driven to run by a sprocket shaft, a chain sprocket and a chain. In the foot-operated vehicle, pedal plates at both sides of a frame are trampled by two feet and the pedal plates are connected with a crank connecting rod on the sprocket shaft of a driving shaft. When the pedal plates are trampled by the two feet, the sprocket shaft of the driving shaft is driven to rotate; simultaneously, the force drives a second sprocket shaft or a third sprocket shaft to rotate in turn through the chain on the sprocket shaft and finally drives the back wheel to rotate, so that the foot-operated vehicle travels forward smoothly and successfully.

Description

Collapsiblely step on driving

Technical field:

The utility model relates to a kind of driving of stepping on of standing and scrunching up and down, and particularly a kind of shape is greatly less than being provided with actuating device on the similar car body of Kickboard Scooter, drives trailing wheel and rotates that the two-wheeled of travelling is collapsible steps on driving.

Background technology:

Along with the development of society in progress, people's living standard is improving gradually, many more people come to realise the importance of health environment-friendly life, emphasis is to the amusement of the exercise of health and life leisure, for satisfy people to ride instead of walk motion and amusement have deep love for demand invention utility model collapsible step on driving before the someone invent out several " scooter " China Patent No. and be respectively: " 200510026045.7 " 200610159443.0 " its complex structure of " 200810040103.5 " " 200910051010.7 " " 200910052350.1 "; three grades of actuating devices utilize chain loaded down with trivial details in the structure of gear combination; the foot-driven lever fix shaft is located at the front upper place of vehicle body; cause the reference position of stretcher too high; people improve at the center when trampling scooter, make the crank of stepping on the pedestrian, and the three-wheel vehicle health of setting is long-pending excessive; weight is big, and resistance to motion is big.A kind of " vehicle is scooter particularly " China Patent No.: the actuating device that " 200380106985.6 " its structure is provided with is reasonable inadequately, particularly be arranged on the anchor fitting that the body understructure rear end is emerged, convex appearance causes the people to step on when capable pin and steps on row inconvenience in the friction that bumps of its parts easily.

Summary of the invention:

The purpose of utility model is fundamentally to overcome above-mentioned defective in deficiency, provides a kind of shape similar less than Kickboard Scooter greatly, is provided with actuating device on the car body, and front-wheel is steering wheel, and is big than trailing wheel, can improve and step on the crossing ability that travels.Trailing wheel is drive wheel, and is little than front-wheel, dwindles the car load volume, makes things convenient for the user to step on row up and down.The vehicle body that front vehicle frame and back vehicle frame are formed is folding to have folder function freely, is to use sprocket shaft all the time, connects wheel disc, and chain direct drive trailing wheel rotates that the two-wheeled of travelling is collapsible steps on driving.

The utility model is to realize like this, the described collapsible driving utilization both feet of stepping on are trampled the stretcher that is arranged on the vehicle frame both sides, two stretchers connect respectively at the crank connecting link on sprocket shaft of imput shaft, when scrunching pedal, both feet just driven the rotation of a sprocket shaft of imput shaft, this power connects the rotation that the rotation that has driven two wheel shafts or three sprocket shafts has successively finally also driven trailing wheel through the chain on the sprocket shaft simultaneously, makes and steps on driving steadily smoothly to overtake.Collapsible in the utility model steps on driving and include: wheel flutter front-wheel (big than trailing wheel), front-wheel turns to by the control of handlebar.One drive wheel trailing wheel (little than front-wheel), described drive wheel trailing wheel is to drive actuating device by trampling the stretcher that is connected two ends on sprocket shaft of imput shaft, drives trailing wheel and rotates.The vehicle body that is arranged between the two-wheeled is made up of in the back vehicle frame front vehicle frame, described front-wheel is located at the front end of vehicle body, described trailing wheel is arranged on the rear end of vehicle body, the front vehicle frame of described vehicle body is arranged on the top of front-wheel, the top of front vehicle frame is provided with the locking slide opening, and a quick detach tie down screw (being used to lock the vehicle body front vehicle frame fixes in the folding of tearing open of back vehicle frame) is installed.(back) portion is provided with the vehicle frame connecting bore in the front vehicle frame, and a standing screw (being used for fixing the connection of front vehicle frame in the car after-frame) is installed.The below of front vehicle frame (bottom) is provided with stretcher fix shaft axis hole, the back vehicle frame of the described vehicle body of installation foot pedal fix shaft (being used for the support and connection of stretcher front end) is arranged on the place ahead in trailing wheel, the rear end of front vehicle frame, and the anterior top end of back vehicle frame is provided with vehicle frame and tears folding location hook device (be used for the back vehicle frame and roll over positioning and locking in tearing open of front vehicle frame) open.The front lower ends of back vehicle frame is provided with after-frame connecting bore (being used for the back vehicle frame in the connection of front vehicle frame).By behind the forward direction the back vehicle frame line of centers on also be provided with successively, sprocket shaft axis hole of imput shaft, two sprocket shaft axis holes, three sprocket shaft axis hole tail places are provided with the trailing wheel supported hole.Sprocket shaft of described imput shaft is installed in sprocket shaft axis hole of imput shaft, the two ends of spindle nose are separately installed with crank, one side (vehicle body right side) of axle has also been installed a Dalian wheel disc and has been placed the centre of crank in the car after-frame, the opposite side of axle (vehicle body left side) is equipped with the imput shaft jam nut, places the back vehicle frame in the centre of crank.Described two sprocket shafts are installed in the two sprocket shaft axis holes, the two ends of spindle nose are installed a hinge wheel dish and a chainlet wheel disc respectively, it is medium and small, and to connect wheel disc corresponding in the hinge wheel dish on one of the imput shaft, and the two is connected with chain, described three sprocket shafts are installed in the three sprocket shaft axis holes, the two ends of axle are installed a hinge wheel dish and a chainlet wheel disc respectively, it is medium and small, and to connect wheel disc corresponding with the hinge wheel dish on two of the imput shaft, and the two is connected with chain, the described drive wheel trailing wheel of F, be installed in the trailing wheel supported hole at car after-frame tail place, the core wheel of trailing wheel has been installed the trailing wheel center shaft, and the ratchet group is housed on the center shaft.One end of axle is equipped with the little chain drum of trailing wheel, and the hinge wheel dish of its little chain drum on three sprocket shafts is corresponding, and with chain the two is connected.The other end of center shaft is provided with the trailing wheel servo axis.The central inner of rear wheel hub is provided with monolateral tooth platform, is incorporated into very heavy on the ratchet group of installing on the trailing wheel center shaft, and the spindle nose two ends of center shaft respectively are equipped with a bearing respectively, places two avris of rear wheel hub centre hole.G two stretchers, described two stretchers are made up of foot-driven lever stretcher and folding respectively, vertically are installed in the both sides of vehicle body respectively.The folding that is provided with on the stretcher is convenient to stretcher and is turned up and open.The stretcher that the front end of two stretchers is connected to the front vehicle frame bottom supports on the fix shaft, and the front middle part of stretcher is connected to the crank connecting link on imput shaft one sprocket shaft.

Utility model of the present utility model is collapsiblely steps on driving and has and small and exquisitely be easy to carry flexibly, elegant in appearance, gets final product amusement, again the advantage that can conveniently ride instead of walk.

Description of drawings

Accompanying drawing 1 is the collapsible stereo appearance figure of stepping on driving

Accompanying drawing 2 is the collapsible structural representation of stepping on driving

Accompanying drawing 3 is the collapsible STRUCTURE DECOMPOSITION figure that steps on driving

Accompanying drawing 4 is the collapsible back vehicle frame of driving and the constructional drawing of back wheels stepped on

Accompanying drawing 5 for collapsible step on driving the spatial structure External view

Accompanying drawing 6 is the collapsible folding scheme drawing of stepping on driving

The specific embodiment:

The utility model is described in further detail below in conjunction with accompanying drawing, embodiment, it is by handlebar 1 and front wheel carrier fork 67 that as shown in Figure 1 collapsible steps on driving, front-wheel 8 has been formed the collapsible steering swivel system of stepping on driving, and the collapsible steering swivel system of stepping on driving has been arranged on vehicle body foremost.Brake handle 2 and brake cable 3. brake gears 9 have been formed the collapsible brake system of stepping on driving of the utility model.Luggage bracket 7 has been fixed on the front wheel spindle 74 on the front wheel carrier fork 67.Front-wheel 8 is housed on the front wheel spindle 74.Also be provided with the adjustment that handlebar locking quick detach 4 is used for being convenient to the handlebar lifting on the handlebar 1.Handlebar folding means 5 provides the comfort feature of handlebar folding.Be provided with locking slide opening 10 on the top of Fig. 1 front vehicle frame 6 shown in Figure 3, be used to install the folding locking of vehicle body quick detach 11.The vehicle frame connecting bore 12 that is provided with of place, back partially at the middle part of front vehicle frame 6, standing screw 12B has played the connection of front vehicle frame 6 in back vehicle frame 13 in vehicle frame connecting bore 12, is convenient to front vehicle frame 6 folding in back vehicle frame 13 again.The bottom lowermost end of front vehicle frame 6 is provided with stretcher and supports fix shaft 20.Described stretcher supports the stretcher support fix shaft axis hole 68 that fix shaft 20 laterally is installed in front vehicle frame 6 bottoms, among the 68B, shown in Fig. 2 Fig. 3, support fix shaft setting nut 45 and be arranged between support fix shaft axis hole 68,68B two holes, played supporting the lateral adjustments effect of fix shaft 20 left and right sides diaxons.Be equipped with two respectively near support positioning shaft hole 68,68B both sides and supported fix shaft jam nuts 44.Two auxiliary wheels 21 are installed in the two ends of supporting on the fix shaft 20 respectively, are positioned at the outside of two jam nuts 44, draw freely smoothly when driving is turned up as collapsible stepping on.Make collapsible driving realization multi-function action---the baggage car (shown in Fig. 6 A) of stepping on.

Described two stretchers 33 are connected on foot-driven lever 33A and 33B by folding 35 respectively.Described folding 35 at least respectively is being equipped with more than 4 on foot-driven lever 33A, the 33B, consults among Fig. 2 Fig. 3 as seen.Folding 35 can be played and make stretcher pack up (dwindling the collapsible volume of stepping on driving) or open (be convenient to user's both feet and step on row), consults Fig. 2 Fig. 3 or Fig. 6 as seen.Described foot-driven lever 33A33B is provided with foot-driven lever supported hole 62 and 64 foremost respectively, 42, two foot-driven lever backup bearings 43 of a foot-driven lever pivot shaft bearing sleeve respectively is housed in the foot-driven lever supported hole 62,64 respectively is installed within the two foot-driven lever backup bearings cover 42.The two ends that described stretcher supports fix shaft 20 be installed in respectively its among 62 and 64 figure consult among 2 Fig. 3 as seen.The avris in the two ends of described support fix shaft 20 is provided with pintle hook lock 41, is used for the locking of pivot shaft after the foot-driven lever assembling.Consult Fig. 3 as seen.

Described foot-driven lever 33A and 33B leading portion position after a while also are provided with a bearing carrier ring 47 all respectively are housed in pitman shaft assembly opening 63 and 65, two holes

As shown in Figure 4, the front upper place of described back vehicle frame 13 is provided with vehicle frame and tears folding positioning and locking hook 56 open, collapsiblely step on driving when deployed condition, its location hook 56 is fixing by (in the locking slide opening 10 that is provided with on the front vehicle frame 6) locking quick detach 11. consult Fig. 1 Fig. 3 as seen.The lower front that is arranged on back vehicle frame 13 is a connecting bore 69, the vehicle frame connecting bore 12 that is provided with on front vehicle frame 6 is corresponding, the horizontal bolt of rear end plate 12B that is positioned at vehicle frame connecting bore 12 through front vehicle frame 6 is fixed together front vehicle frame 6 and back vehicle frame 13, consults Fig. 1 Fig. 3 finding

Be provided with sprocket shaft axis hole 59 of imput shaft and two sprocket shaft axis holes, 60 3 sprocket shaft axis holes, 61. above three sprocket

shaft axis holes

59,60,61 on the vehicle frame 13 of described as shown in Figure 4 back respectively and all distinguish lateral direction penetrating in back vehicle frame 13

Shown in Figure 4 as Fig. 2 Fig. 3, sprocket shaft 15 of described imput shaft is loaded in axis hole 59 of imput shaft, and two bearings 50. is contained in respectively on sprocket shaft 15 of imput shaft, is arranged in two avris of an axis hole 59 of imput shaft.Sprocket shaft jam nut 51 of imput shaft places the side (vehicle body left side) on sprocket shaft 15 of imput shaft.The opposite side of a sprocket shaft of imput shaft (vehicle body right side) has been installed hinge wheel dish 14 of imput shaft.Right crank 16 has been installed in right edge end on imput shaft one sprocket shaft 15 by main shaft connecting bore 70, and the perch hole 71 that be located on the right crank 16 this moment should be downward position.Perch 18 is assemblied in the perch hole 71.Left side crank 17 has been installed in limit, the opposite side left side end of a sprocket shaft 15 of imput shaft by main shaft connecting bore 70B, and the perch hole 71B that is located at this moment on the left crank 17 should be position upwards, and perch 18 is assemblied in the 71B of perch hole.

As shown in Figure 3, described connecting rod has two of right connecting rod 19 and left connecting rod 19B., and right connecting rod (19) is symmetrical arranged with left connecting rod (19B).Assembling main shaft bearing 49 is installed on the perch 18 in one stomidium of its right connecting rod 19.Bearing carrier ring 47 places the pitman shaft assembly opening 63 on the foot-driven lever 33A, and pitman shaft bearing 48 is installed in the bearing carrier ring 47, and the other end of right connecting rod 19 is installed in the pitman shaft bearing 48 by pitman shaft 72.Tie down screw 22 crosses in the connecting rod assembly opening 63 on the foot-driven lever 33A and be connected to form locking in pitman shaft 72.

As shown in Figure 3, assembling main shaft bearing 49 is installed on the perch 18 in the stomidium of described left connecting rod 19B.Bearing carrier ring 47 is loaded in the pitman shaft assembly opening 65 on the foot-driven lever 33B, and the little axle bearing 48 of connecting rod is installed in the bearing carrier ring 47, and the other end of left connecting rod 19B is installed in the pitman shaft bearing 48 by pitman shaft 72B.Tie down screw 22 crosses in the connecting rod assembly opening 65 on the foot-driven lever 33B and be connected to form locking in pitman shaft 72B.

Shown in Figure 3 as Fig. 2, described two sprocket shafts 31 are contained in the two sprocket shaft axis holes 60, and two bearings 52 is contained in respectively on two sprocket shafts 31, is positioned at two avris of two sprocket shaft axis holes 60.One end of two sprocket shafts 31 (right side of back vehicle frame 13) is installed a chainlet wheel disc 24, and the Dalian wheel disc 14 of chainlet wheel disc 24 on imput shaft one sprocket shaft 15 is corresponding.Chain 23 is installed on Dalian wheel disc 14 and the chainlet wheel disc 24, forms the power transmission between imput shaft one sprocket shaft 15 and two sprocket shafts 31.The other end of two sprocket shafts 31 (left side of back vehicle frame 13) is installed a hinge wheel dish 28.

Described three sprocket shafts 32 are installed in the three sprocket shaft axis holes 61, two bearings 53 is installed in respectively on three sprocket shafts 32, be arranged in two avris of three sprocket shaft axis holes 61, one end of three sprocket shafts 32 (left side of back vehicle frame 13) is installed a chainlet wheel disc 30, and chainlet wheel disc 30 is corresponding with the hinge wheel dish 28 on two sprocket shafts 31.Chain 29 is installed on hinge wheel dish 28 and the chainlet wheel disc 30, forms the power transmission between two sprocket shafts 31 and three sprocket shafts 32.

Described drive wheel trailing wheel 66 is installed in the trailing wheel supported hole 5758 of back vehicle frame 13 caudal end.Hind axle bowl 38 is installed in respectively in the trailing wheel supported hole 5758, and back wheel support bearing 54 is installed in respectively in the two hind axle bowls 38.The inside, core wheel hole of rear-wheel hub 36 is provided with monolateral tooth platform, trailing wheel center shaft 34 is loaded in the core wheel hole of rear-wheel hub, and ratchet 37 is housed on the center shaft 34, is provided with very heavy 73 on the ratchet 37, take turns intracardiac monolateral tooth platform frictional engagement in rear-wheel hub 36, form unidirectional promotion.Two rear wheel hub bearings 55 are installed in two avris that two ends on the center shaft 34 place the core wheel hole on the rear wheel hub 36 respectively.Two bearing washers 40 are close to bearing 55 respectively.Trailing wheel chainlet dish 27 crosses trailing wheel supported hole 58, hind axle bowl 38, an end combination of the trailing wheel center shaft 34 of back wheel support bearing 54 on rear wheel hub 36.The hinge wheel dish 25 of trailing wheel chainlet dish 27 on three sprocket shafts 32 is corresponding, and chain 26 is installed on the hinge wheel dish 25 and trailing wheel chainlet dish 27 on three sprocket shafts 32, has formed the power transmission between three sprocket shafts 32 and the trailing wheel chainlet wheel disc 27.Trailing wheel servo axis 39 is by crossing trailing wheel supported hole 57, the other end (left end) combination on the trailing wheel center shaft 34 on the rear wheel hub 34 of hind axle bowl 38, back wheel support bearing 54.Trailing wheel 66 is on the rear wheel hub on 36.

Claims

1. collapsible step on the driving be by handlebar (1), brake handle (2), brake cable (3). brake gear (9), a bigger front-wheel (8), a less trailing wheel (66), front wheel carrier fork (67), front vehicle frame (6) back vehicle frame (13) is formed, it is characterized in that vehicle body by front vehicle frame (6) with the back vehicle frame (13) form, front vehicle frame (6) can go up the after-frame connecting bore (69) that is provided with back vehicle frame (13) by the vehicle frame connecting bore (12) that is arranged on front vehicle frame (6) postmedian with back vehicle frame (13) and be connected, bottom, front vehicle frame (6) lower end is provided with stretcher and supports fix shaft (20), front-wheel (8) is a steering wheel, trailing wheel (66) is a drive wheel, also be provided with handlebar locking quick detach (4) on the handlebar (1), folding means (5), luggage bracket (7) have been fixed on the front wheel spindle (74) on the front wheel carrier fork (67).

2. the collapsible driving of stepping on as claimed in claim 1 is characterized in that being provided with locking slide opening (10) on the top of front vehicle frame (6), and vehicle body folding locking quick detach (11) is installed on the locking slide opening (10).

3. the collapsible driving of stepping on as claimed in claim 1 is characterized in that being provided with standing screw (12B) in vehicle frame connecting bore (12) in the vehicle frame connecting bore (12) that the place, back is provided with partially of the middle part of front vehicle frame (6).

4. the collapsible driving of stepping on as claimed in claim 1, it is characterized in that being provided with stretcher support fix shaft (20) at the bottom lowest part of front vehicle frame (6), stretcher supports the stretcher support fix shaft axis hole (68 that fix shaft (20) laterally is installed in front vehicle frame (6) bottom, 68B), pivot shaft setting nut (45) is arranged on pivot shaft axis hole (68) (68B) between two holes, be convenient to stretcher and support laterally left and right adjusting of fix shaft (20), (68B) two support fix shaft jam nuts (44) have been equipped with respectively in both sides near supporting axis hole (68), two auxiliary wheels (21) are installed in the two ends of supporting on the fix shaft (20) respectively, are positioned at the outside of two fix shaft jam nuts (44).

5. as claim 1, the 4 described collapsible drivings of stepping on, the two ends that it is characterized in that stretcher support fix shaft (20) are respectively arranged with foot-driven lever supported hole (62) and (64), two stretchers (33) are connected by on folding (35) and foot-driven lever (33A) and (33B) respectively, described folding (35) respectively is equipped with more than 4 on (33B) at foot-driven lever (33A), foot-driven lever (33A) (33B) be arranged at foot-driven lever supported hole (62) and (64) foremost respectively, a foot-driven lever pivot shaft bearing sleeve (42) respectively is housed in the foot-driven lever supported hole (62) (64), two foot-driven lever backup bearings (43) respectively are installed within the two foot-driven lever backup bearing covers (42), the avris in the two ends of pivot shaft (20) is provided with pintle hook lock (41), foot-driven lever (33A) and (33B) leading portion position after a while also be provided with pitman shaft assembly opening (63) and (65), a bearing carrier ring (47) all respectively is housed in two holes.

6. the collapsible driving of stepping on as claimed in claim 1, it is characterized in that being provided with locking bail (56) in the front upper place of back vehicle frame (13), the front lower ends of back vehicle frame (13) is after-frame connecting bore (69), corresponding with the vehicle frame connecting bore (12) that front vehicle frame (6) go up to be provided with, laterally the bolt of rear end plate (12B) that is positioned at vehicle frame connecting bore (12) through vehicle body (6) is fixed together front vehicle frame (6) and back vehicle frame (13).

7. the collapsible driving of stepping on as claimed in claim 1 is characterized in that back vehicle frame (13) gone up a respectively horizontally set sprocket shaft axis hole of imput shaft (59), two sprocket shaft axis holes (60), three sprocket shaft axis holes (61) and trailing wheel supported hole (57), (58).

8. as claim 1, the 7 described collapsible drivings of stepping on, it is characterized in that a sprocket shaft of imput shaft (15) is loaded in the axis hole of imput shaft (59), two bearings (50) is contained in respectively on the sprocket shaft of imput shaft (15), be arranged in two avris of an axis hole of imput shaft (59), a sprocket shaft jam nut of imput shaft (51) places the side on the sprocket shaft of imput shaft (15), the opposite side of a sprocket shaft of imput shaft has been installed a hinge wheel dish of imput shaft (14), right crank (16) has been installed in right edge end on imput shaft one sprocket shaft (15) by main shaft connecting bore (70), perch hole (71) on the right crank (16) is to upper/lower positions, perch (18) is assemblied in the perch hole (71), left side crank (17) has been installed in limit, the opposite side left side end of a sprocket shaft of imput shaft (15) by main shaft connecting bore (70B), the perch hole (71B) that is located on the left crank (17) is position upwards, perch (18) is assemblied in the perch hole (71B), and right connecting rod (19) is symmetrical arranged with left connecting rod (19B).

9. as claim 7, the 8 described collapsible drivings of stepping on, it is characterized in that assembling main shaft bearing (49) in the stomidium of right connecting rod (19), be installed on the perch (18), bearing carrier ring (47) places the pitman shaft assembly opening (63) on the foot-driven lever (33A), pitman shaft bearing (48) is installed in the bearing carrier ring (47), the other end of right connecting rod (19) is installed in the pitman shaft bearing (48) by pitman shaft (72), and tie down screw (22) crosses in the connecting rod assembly opening (63) on the foot-driven lever (33A) and connects in pitman shaft (72).

10. the collapsible driving of stepping on as claimed in claim 8, it is characterized in that assembling main shaft bearing (49) in the stomidium of left connecting rod 19B, be installed on the perch (18), bearing carrier ring (47) is loaded in the pitman shaft assembly opening (65) on the foot-driven lever (33B), the little axle bearing of connecting rod (48) is installed in the bearing carrier ring (47), the other end of left side connecting rod (19B) is installed in the pitman shaft bearing (48) by pitman shaft (72B), and tie down screw (22) crosses in the connecting rod assembly opening (65) on the foot-driven lever (33B) and connects in pitman shaft (72B).

11. the collapsible driving of stepping on as claimed in claim 7, it is characterized in that two sprocket shafts (31) are contained in the two sprocket shaft axis holes (60), two bearings (52) is contained in respectively on two sprocket shafts (31), be positioned at two avris of two sprocket shaft axis holes (60), one end of two sprocket shafts (31) is installed a chainlet wheel disc (24), chainlet wheel disc (24) is corresponding with the Dalian wheel disc (14) on the sprocket shaft of imput shaft (15), chain (23) is installed on Dalian wheel disc (14) and the chainlet wheel disc (24), the other end of two sprocket shafts (31) is installed a hinge wheel dish (28), three sprocket shafts (32) are installed in the three sprocket shaft axis holes (61), two bearings (53) is installed in respectively on three sprocket shafts (32), be arranged in two avris of three sprocket shaft axis holes (61), one end of three sprocket shafts (32) is installed on chainlet wheel disc (30), chainlet wheel disc (30) is corresponding with the hinge wheel dish (28) on two sprocket shafts (31), and chain (29) is installed on hinge wheel dish (28) and the chainlet wheel disc (30).

12. collapsiblely step on driving as what claim 1 was stated, it is characterized in that drive hub (36), be installed in the trailing wheel supported hole (57) of back vehicle frame (13) tail end, (58) in, hind axle bowl (38) is installed in trailing wheel supported hole (57) respectively, (58) in, back wheel support bearing (54) is installed in respectively in the two hind axle bowls (38), the wheel interior portion of rear-wheel hub (36) is provided with monolateral tooth platform, in the core wheel hole of trailing wheel center shaft (34) dress and rear-wheel hub (36), ratchet group (37) is housed on the center shaft (34), be provided with on the ratchet (37) very heavy (73), with the intracardiac monolateral tooth platform frictional engagement of rear-wheel hub (36) wheel, form unidirectional promotion, two rear wheel hub bearings (55) are installed in two avris that two ends on the center shaft (34) place the core wheel hole on the rear wheel hub (36) respectively, two bearing washers (40) are close to bearing (55) respectively, trailing wheel small tooth plate (27) crosses trailing wheel supported hole (58), hind axle bowl (38), one end combination of the trailing wheel center shaft (34) of back wheel support bearing (54) on rear wheel hub (36), the hinge wheel dish (25) of the little chain drum of trailing wheel (27) on three sprocket shafts (32) is corresponding, chain (26) is installed on the hinge wheel dish (25) and the little chain drum of trailing wheel (27) on three sprocket shafts (32), trailing wheel servo axis (39) is by crossing trailing wheel supported hole (57), hind axle bowl (38), the other end left end combination of back wheel support bearing (54) on the trailing wheel center shaft (34) on the rear wheel hub (34).