CN219601533U

CN219601533U - Inner speed-changing hub and front wheel driving bicycle thereof

Info

Publication number: CN219601533U
Application number: CN202320881565.XU
Authority: CN
Inventors: 陈雪妍
Original assignee: Individual
Current assignee: Individual
Priority date: 2023-04-19
Filing date: 2023-04-19
Publication date: 2023-08-29
Anticipated expiration: 2033-04-19

Abstract

The utility model discloses an internal speed-changing hub which comprises an input shaft, an output gear, a hub shell, a duplex gear shaft, a duplex gear, a pawl, a ratchet seat, an input gear, a bearing seat, a fork frame and a pawl spring, wherein the hub shell is driven to rotate around the input shaft when the input shaft rotates anticlockwise relative to the input gear, and the input shaft cannot be driven to rotate when the input shaft rotates clockwise relative to the input gear. The front wheel driving bicycle is characterized by comprising a front wheel set, pedals, a front fork, a handle, a frame, a seat cushion, a backrest, a rear fork and a rear wheel set, wherein the front wheel driving bicycle takes the inner speed changing hub as a core, the front wheel driving bicycle is an application of the inner speed changing hub, and the front wheel driving bicycle is driven by the front wheel and is provided with the backrest.

Description

Inner speed-changing hub and front wheel driving bicycle thereof

Technical Field

The utility model relates to an internal speed-changing hub and a front wheel driven bicycle thereof, which are mainly applied to bicycles, tricycles, motorcycles, automobiles and other devices using internal speed changing.

Background

The bicycle and tricycle are used as environment-friendly and energy-saving transportation means, have wide application, great social and economic significance, but have defects, and need to be continuously improved, the driving wheels of the existing bicycles, tricycles and motorcycles mostly adopt chains to transmit power and change rotating speed, the rear wheels are driven by a chain transmission mechanism, the chains are exposed, and the chain is easy to fall off due to the defects of difficult lubrication, easy rust and corrosion, poor reliability, low transmission efficiency and the like. Some bicycles also use an inner gear shifting hub with a planetary gear shifting mechanism, which integrates the shifting mechanism in the hub, but the inner gear shifting hub is as same as the common hub, the axle at the axial position is fixed in the fork frame and does not transmit power, the inner gear shifting hub can only be installed on the rear wheel, the power is transmitted to the input wheel of the inner gear shifting hub by a chain instead of the axle, the inner gear shifting hub also needs to use a chain as the common hub, the defects of difficult lubrication, easy rust and the like of the chain transmission still exist, meanwhile, the planetary gear shifting mechanism is as expensive as more than ten times that of the common hub, and the installation and arrangement are inflexible, can only be installed on the rear wheel, and the front wheel driving can not be realized.

Disclosure of Invention

In order to solve the defects of the prior art, the internal speed-changing hub is characterized in that the gear speed-changing mechanism and the ratchet mechanism are integrated in the hub shell to realize the input of the rotating speed through the wheel shaft, the hub is driven to rotate at the proper rotating speed after the speed-changing mechanism changes speed, the whole transmission system is compact in structure, the transmission mechanism is built in the hub, the power is input through the wheel shaft (called as an input shaft in the description), the internal speed-changing hub is economical and reliable, the installation position is flexible, namely the internal speed-changing hub can be installed on a rear wheel and also can be installed on a front wheel, the front wheel is driven without a chain to transmit the power, and the front wheel is directly driven to rotate through the internal speed-changing hub, so that the defects of difficult lubrication, easy rust, poor reliability, low transmission efficiency and the like of chain transmission are overcome, the chain is never lost, and the structure is simplified.

The bicycle is characterized in that the bicycle comprises a front wheel driving wheel, a rear wheel driving wheel and a rear wheel driving wheel, wherein the front wheel driving wheel is used as a core of the inner speed changing wheel, the front wheel driving wheel is used for driving the front wheel driving wheel, the rear wheel driving wheel is used for driving the rear wheel driving wheel, and the rear wheel driving wheel is used for driving the rear wheel driving wheel.

The invention is realized in the following way:

for convenience of explanation, when the rotation direction is described below, counterclockwise rotation or clockwise rotation is obtained from left to right or from front to back.

An internal speed-changing hub comprises an input shaft, an output gear, a hub shell, a duplex gear shaft, a duplex gear, a pawl, a ratchet seat, an input gear, a bearing seat, a fork frame and a pawl spring, wherein the bearing seat is fixed on the fork frame, a bearing hole is formed in the bearing seat, the input shaft is arranged in the bearing hole of the bearing seat through a bearing, the input shaft rotates circumferentially and is axially fixed, and the ratchet seat is fixed on the input shaft or is integrated with the input shaft;

one end of the hub shell is arranged on the input shaft through a bearing, the other end of the hub shell is arranged on a large end outer cylinder of the bearing seat through a bearing, the large end outer cylinder of the bearing seat is coaxial with the input shaft, and the hub shell can rotate around the input shaft;

the input gear is sleeved on the input shaft through a bearing, and the input gear is axially fixed and circumferentially rotatable;

the double gear is arranged on a double gear shaft through a bearing, the double gear can rotate around the double gear shaft, the double gear shaft is fixed in the bearing seat, and the axis of the double gear shaft is parallel to the axis of the input shaft;

The double gear comprises a right end gear and a left end gear which are coaxially connected, the right end gear of the double gear is meshed with the input gear, the left end gear of the double gear is meshed with the output gear, the output gear is fixed in the hub shell, the output gear is provided with a through hole, the input shaft penetrates through the through hole of the output gear, and the axis of the output gear is coaxial with the axis of the input shaft;

the pawl is positioned between the ratchet seat and the input gear, and is processed with a cylindrical surface and a ratchet;

the input gear is provided with tooth grooves or semi-cylindrical holes, the ratchet seat is provided with the semi-cylindrical holes or tooth grooves, the semi-cylindrical holes of the ratchet seat or the semi-cylindrical holes of the input gear are in clearance fit with cylindrical surfaces of pawls, the pawls rotate around the axes of the semi-cylindrical holes, the pawls are provided with pawl springs, and the ratchets on the pawls have a tendency of being inserted into the tooth grooves of the ratchet seat or the tooth grooves of the input gear under the action of the pawl springs;

the ratchet seat, the pawl and the input gear form a ratchet mechanism, when the input shaft rotates anticlockwise relative to the input gear, the pawl is always embedded in the tooth slot, the input shaft drives the input gear to rotate anticlockwise through the ratchet seat and the pawl, the input gear drives the duplex gear to rotate, and the duplex gear drives the output gear and the hub shell to rotate around the input shaft; when the input shaft rotates clockwise relative to the input gear, the pawl slides out of the tooth groove, the ratchet teeth of the pawl and the tooth groove are in a separation state, and the input shaft cannot drive the hub shell to rotate.

Preferably, the fork frame is a part on a bicycle, tricycle, automobile and other automobile bodies, including a front fork, a rear fork frame, an automobile body and the like.

Preferably, the ratchet seat is machined with a square hole that mates with a square journal on the input shaft.

Preferably, the ratchet seat is machined with a splined bore that mates with a splined journal on the input shaft.

Preferably, the ratchet seat is provided with a round hole, and is fixed on the input shaft through interference fit.

Preferably, the ratchet seat is provided with a round hole, is tightly sleeved in the input shaft and is fixed on the input shaft by welding.

Preferably, the ratchet seat and the input shaft are integrally formed.

In order to improve the stress condition of the components, preferably, 2 to 4 duplex gears are arranged and are distributed uniformly or centrally symmetrically relative to the input shaft.

In order to enhance the rigidity of the duplicate gear shafts, preferably, the duplicate gear shafts are all connected at the free ends thereof by reinforcing rings, the reinforcing rings are provided with inner holes of the same number as the duplicate gear shafts, and the free ends of all the duplicate gear shafts are inserted into the inner holes corresponding to the reinforcing rings.

Preferably, the pawls are circumferentially uniformly distributed, the number of the pawls is 2 to 4, and the pawls have 1 to 5 ratchets.

Preferably, the ratchet seat is provided with a tooth socket, the input gear is provided with a semi-cylindrical hole, the pawl is arranged on the outer side of the tooth socket, the semi-cylindrical hole on the input gear is in clearance fit with the cylindrical surface on the pawl, the pawl axially extends out of the input gear, a pawl spring is arranged at the part of the pawl extending out of the input gear, and the ratchet on the pawl has a tendency of being inserted into the tooth socket on the ratchet seat under the action of the spring.

Preferably, the pawl spring is a spring ring with an opening, two ends of the spring ring are hooked, the bent hooks are inwards, the spring ring has a tendency of inwards shrinking, and the spring ring presses the pawl from outside to inside, so that the pawl has a tendency of inwards rotating.

Preferably, the ratchet surface of the left end of the pawl protrudes, and the axial length of the ratchet surface of the pawl is larger than that of the cylindrical surface of the pawl.

Preferably, the input gear is provided with a tooth socket, the ratchet seat is provided with a semi-cylindrical hole, the pawl is positioned at the inner side of the tooth socket, the semi-cylindrical hole on the ratchet seat is in clearance fit with the cylindrical surface on the pawl, the pawl axially extends out of the input gear, a pawl spring is arranged at the part of the pawl extending out of the input gear, and the ratchet on the pawl has a tendency of being inserted into the tooth socket on the input gear under the action of the spring. Preferably, the pawl spring is a spring ring with an opening, the spring ring has an outward opening trend, the pawl is pressed by the spring ring from inside to outside, the pawl generates an outward rotation trend, and two ends of the spring ring are in a hook shape and are bent outwards. Preferably, the ratchet surface of the left end of the pawl protrudes, and the axial length of the ratchet surface of the pawl is larger than that of the cylindrical surface of the pawl.

Preferably, the input gear is provided with a tooth socket, the ratchet seat is provided with a semi-cylindrical hole, the pawl is positioned at the inner side of the tooth socket, the semi-cylindrical hole on the ratchet seat is in clearance fit with the cylindrical surface on the pawl, the cylindrical surface at the left end of the pawl is convex, the cylindrical surface of the pawl axially extends out of the input gear, the pawl spring is arranged on the pawl cylindrical surface extending out of the input gear, and the pawl cylindrical surface extending out of the input gear is provided with an inclined plane.

The inclined surface makes the spring acting force on the contact point of the pawl spring and the cylindrical surface deviate from the center of the cylindrical surface, and the pawl generates outward rotation trend under the action of the spring.

Preferably, the pawl spring is a circlip with a tendency to retract inwardly which presses the pawl from the outside to the inside causing the ratchet teeth on the pawl to have a tendency to insert into the tooth spaces on the input gear.

To limit the axial movement of the pawl, the ratchet seat is preferably machined with a ring groove into which the spring ring snaps.

In order to limit the spring ring to rotate around the input shaft, preferably, two ends of the spring ring are hooked, the bent hooks are inwards, the ratchet seat is provided with a groove, and the hooked spring wires at two ends of the spring ring are clamped into the groove.

Preferably, the hub shell is machined with a connecting inner hole for fixing the output gear, and the output gear is pressed into the connecting inner hole of the hub shell by interference fit.

Preferably, the cylindrical surface at the left end of the output gear is provided with external threads, the connecting inner hole of the hub shell is provided with internal threads, the output gear is screwed in a screw hole of the hub shell, the screwing direction of the threads is the same as the power input steering direction of the input shaft, and the output gear is ensured to be firmly fixed in the hub shell when being screwed more and more in operation.

Preferably, the output gear is integrally fixed in the hub shell as an insert of the hub shell during the die casting of the hub shell.

Preferably, a threaded hole is formed at one end of the output gear, and the output gear is fixed in the hub shell by screw connection, so that the output gear is more reliably fixed in the hub shell by combining other connection methods.

Preferably, the inner speed-changing hub further comprises a left brake block, a right brake block, a brake fixed shaft, a rocker arm and a brake rotating shaft, wherein the brake fixed shaft is fixed on the fork frame, the fork frame is provided with a rotating shaft inner hole, the brake rotating shaft is in clearance fit with the rotating shaft inner hole of the fork frame, one section of the brake rotating shaft is arranged in the rotating shaft inner hole of the fork frame, one end of the brake rotating shaft is fixed with the rocker arm, when the rocker arm rotates under the action of the pulling force of a brake wire, the rocker arm drives the brake rotating shaft to rotate, the part, which is contacted with the brake rotating shaft, is a square shaft, the section shape is approximately rectangular, and when the brake rotating shaft rotates, the brake rotating shaft drives the left brake block and the right brake block to rotate around the brake fixed shaft through the square shaft, so that the left brake block and the right brake block are expanded and compress the hub shell, the hub shell is further decelerated or stopped rotating, the left brake block and the right brake block are pulled with a spring, and the left brake block and the right brake block are reset when the brake wire does not exert the pulling force.

A front wheel drive bicycle is a specific application of the inner speed-changing hub, the bicycle omits a chain and a tripod, the structure is simple and reliable, the bicycle is easy to maintain, the bicycle body can be made to be very short and is easy to place in a car trunk, the bicycle is convenient to travel, more importantly, compared with the common bicycle pedal arranged below a seat cushion, the front wheel drive bicycle pedal is arranged on the front wheel and below the seat cushion, the body of a rider can lean backwards to realize semi-lying riding, unlike the common bicycle rider which only has the bearing force of the buttocks and is prone to ride, the bicycle is driven by the front wheel to pedal forwards and downwards, the back can bear force simultaneously due to the slight leaning backwards, the bicycle is like a car, the seat cushion with large use area can be used in the thigh, the bicycle is comfortable and durable, the bicycle is different from the common bicycle, in experience, the bicycle is convenient to ride, the bicycle is convenient to park because the pedal forwards and downwards, the bicycle is stopped down, the bicycle can not prone to ride down when the bicycle is stopped, and can stand down in a sudden, the bicycle can not ride down, and the bicycle is convenient to ride down.

The front wheel is driven without a chain to transmit power, and the front wheel set is directly driven to rotate through the inner speed-changing hub, so that the bicycle is made to move forward, the defects that the chain transmission is exposed and is difficult to lubricate, easy to rust, poor in reliability, low in transmission efficiency and the like are overcome, the chain is never lost, and the structure is simplified, so that the cost is saved.

The front wheel driving bicycle comprises a front wheel set, pedals, a front fork, a handle, a frame, a seat cushion, a backrest, a rear fork and a rear wheel set, wherein the front wheel set comprises spokes, a rim and an inner speed changing hub, the spokes are used for connecting and fixing the rim and a hub shell, the front wheel set is arranged on the front fork through bearing blocks, the bearing blocks are fixed on the front fork, the pedals are fixed at two ends of an input shaft of the inner speed changing hub, the front fork is connected with the handle and is arranged on the frame through bearings, the seat cushion is arranged on the frame, the backrest is arranged behind the seat cushion, the rear fork is arranged behind the frame, and the rear wheel set is arranged on the rear fork;

when the pedal is stepped on, the input shaft is driven to rotate, the rotation speed of the input shaft is changed by the inner speed changing hub to drive the hub shell to rotate, the rim is fixedly connected with the hub shell through spokes, the whole front wheel set rotates along with the stepping of the pedal, and the front wheel set drives the bicycle to move when rotating.

Preferably, the front fork is similar to a single-side fork frame of a common front fork, a through hole is formed in the lower portion of the front fork, an input shaft penetrates through the through hole, bolt holes for mounting bolts are formed around the through hole, and a bearing seat is fixed on the front fork through bolt connection.

Preferably, the rod body of the front fork is of a hollow structure, the lower hollow structure is opened leftwards, and the upper hollow structure is opened rightwards.

Preferably, the upper end of the front fork is provided with a vertical inner hole.

Preferably, the brake fixed shaft is used as an insert of the front fork and is integrally fixed in the front fork during the die casting of the front fork.

Preferably, the crosspiece of the frame is similar to the crosspiece on a tripod of a common bicycle and is positioned at the upper part of the tripod of the common bicycle, the rear part of the crosspiece of the frame is fixed with a rear fork, and the crosspiece, the rear fork and the like form the whole of the frame.

Preferably, the crosspiece of the frame is square in cross section, the seat cushion is arranged on the crosspiece, the seat cushion is provided with a locking clamp, the locking clamp is sleeved in the crosspiece, the seat cushion can move along the crosspiece, and the locking clamp is clamped to fix the seat cushion after the seat cushion moves to a proper position.

Preferably, the crosspiece of the frame is a half square section, the contact part of the crosspiece and the seat cushion is a plane, and the cross section of the crosspiece matched with the clamping face of the clamp is an arc surface.

Preferably, the rail of the frame is provided with a backrest, the backrest is arranged behind the seat cushion, the backrest is provided with a locking clamp which is sleeved in the rail, the backrest and the seat cushion can move along the rail together, and the backrest and the seat cushion can clamp the locking clamp to fix the backrest after moving to a proper position.

The invention has the beneficial effects that:

the internal speed-changing hub integrates the ratchet mechanism, the gear speed-changing mechanism and the braking mechanism, the hub obtains proper rotation speed and steering through the gear speed-changing mechanism, the input shaft drives the hub in a counterclockwise and unidirectional way through the ratchet mechanism, and the whole structure is built in the hub shell, so that the internal speed-changing hub is compact and simple;

the internal speed-changing hub overcomes the defects of difficult lubrication, easy rust and corrosion, poor reliability, low transmission efficiency and the like of chain transmission exposed outside, and achieves the effects of no chain drop, convenient lubrication, compactness, reliability and the like.

The front wheel driven bicycle omits a chain and a tripod, has the advantages of simple and reliable structure, easy maintenance, convenient storage, easy placement in a trunk of a car, convenient travel and use, semi-lying riding, improvement of the stress condition of a rider, comfortable and durable riding, safety and convenience.

Drawings

For a clearer description of embodiments of the invention or of solutions in the prior art, the figures used in the description of the embodiments or of the prior art will be briefly described, which are only some embodiments of the invention, from which it is obvious that other figures can be obtained by a person skilled in the art without inventive effort.

FIG. 1 is a schematic view of the assembly of the present invention;

FIG. 2 is an assembled schematic front view of a bearing housing with 2 duplex gears mounted thereon according to the present invention;

FIG. 3 is a schematic left-hand view of a toothed input gear of the present invention;

FIG. 4 is a schematic left-hand view of the semi-cylindrical bore input gear of the present invention;

FIG. 5 is a schematic left-hand view of the toothed ratchet seat of the present invention;

FIG. 6 is a schematic left-hand view of the ratchet seat with semi-cylindrical holes of the present invention;

FIG. 7 is a schematic left-hand view of a splined ratchet holder of the present invention;

FIG. 8 is a schematic cross-sectional view of the input shaft of the present invention with the ratchet seat and the input shaft being integral;

FIG. 9 is a schematic front view of the input shaft of the present invention with the ratchet seat and the input shaft being integral;

FIG. 10 is a schematic left side view of a pawl of the present invention;

FIG. 11 is a schematic top view of the pawl of the present invention;

FIG. 12 is a schematic left-hand view of a beveled pawl of the present invention;

FIG. 13 is a schematic top view of a beveled pawl in accordance with the present invention;

FIG. 14 is a schematic left side view of the external engagement ratchet mechanism of the present invention;

FIG. 15 is a schematic left side view of the ring gear ratchet of the present invention;

FIG. 16 is a schematic view of a spring ring installation in the external engagement ratchet mechanism of the present invention;

FIG. 17 is a schematic view of the shape of a spring coil in the external engagement ratchet mechanism of the present invention;

FIG. 18 is a schematic illustration of the installation of a camber spring ring in the inner-mesh ratchet mechanism of the present invention;

FIG. 19 is a schematic view of the shape of the outwardly bowed spring coils in the inner ratchet mechanism in accordance with the present invention;

FIG. 20 is a schematic view of the installation of a circlip in the ring-in ratchet mechanism of the present invention;

FIG. 21 is a schematic illustration of the shape of a coil of the innerspring in the innerratchet mechanism of the invention;

FIG. 22 is an enlarged partial schematic view of the ratchet mechanism of the present invention;

FIG. 23 is a schematic front view of another construction of an output gear of the present invention;

FIG. 24 is a schematic front elevational view of the hub shell with the output gear mounted thereto in accordance with the present invention;

FIG. 25 is an assembled schematic front view of the present invention with a brake mechanism;

FIG. 26 is an assembled left side schematic view of the brake mechanism of the present invention;

FIG. 27 is a schematic view of a front wheel drive bicycle in accordance with the present invention;

FIG. 28 is a front elevational schematic view of the front fork of the front wheel drive bicycle of the present invention;

FIG. 29 is a left side schematic view of a front fork of the front wheel drive bicycle of the present invention;

FIG. 30 is a schematic left side view of an assembly of the wheel hub and front fork of the present invention;

FIG. 31 is a schematic view of the seating pad installation of the present invention;

figure 32 is a schematic view of a seating pad installation with a cross-piece of the invention in half.

In the figure, 1-input shaft, 2-output gear, 3-hub shell, 4-duplex gear shaft, 5-duplex gear, 6-pawl, 7-ratchet seat, 8-input gear, 9-bearing seat, 10-fork frame, 11-pawl spring, 18-brake pad, 19-brake dead axle, 20-rocker arm, 21-brake rotating shaft, 24-reinforcing ring, 25-front wheel set, 26-pedal, 27-front fork, 28-handle, 29-frame, 30-seat cushion, backrest-31, 32-rear fork, 33-rear wheel set, 201-external thread, 202-screw, 601-ratchet on pawl, 602-cylindrical surface on pawl, 603-cylindrical surface inclined plane of pawl, 701-toothed ratchet seat, 702-ratchet seat with semi-cylindrical hole, 7011-tooth socket on ratchet seat, 7022-semi-cylindrical hole on ratchet seat, 703-square hole on ratchet seat, 704-ring groove, 705-groove, 707-spline hole on ratchet seat, 801-toothed input gear, 802-semi-cylindrical hole input gear, 8011-tooth socket on input gear, 8022-semi-cylindrical hole on input gear, 901-bearing seat large end outer cylinder, 111-external engagement spring ring, 113-external curved internal engagement spring ring, 114-internal curved internal engagement spring ring, 272-through hole on lower part of front fork, 273-bolt hole on lower part of front fork, 274-rotating shaft inner hole, 291-crosspiece square section, 292-square locking clamp, 293-crosspiece half square section, 294-semi-square locking clamp.

Detailed Description

The present invention is further described below with reference to the drawings and the detailed description, but the scope of the invention is not limited thereto, and all equivalent changes and modifications are included in the scope of the present invention.

Example 1

As shown in fig. 1 and 25, an internal speed-changing hub comprises an input shaft 1, an output gear 2, a hub shell 3, a duplex gear shaft 4, a duplex gear 5, a pawl 6, a ratchet wheel seat 7, an input gear 8, a bearing seat 9, a fork 10 and a pawl spring 11, wherein the bearing seat 9 is fixed on the fork 10, a bearing hole is formed in the center of the bearing seat 9, the input shaft 1 is installed in the bearing hole of the bearing seat 9 through a bearing, the input shaft 1 rotates circumferentially and is axially fixed, and the ratchet wheel seat 7 is fixed on the input shaft 1, or the ratchet wheel seat 7 and the input shaft 1 are integrated;

one end of the hub shell 3 is arranged on the input shaft 1 through a bearing, the other end of the hub shell 3 is arranged on a bearing seat large end outer cylinder 901 through a bearing, the bearing seat 9 large end outer cylinder 901 and the input shaft 1 are coaxial (as shown in figure 2), the hub shell 3 can rotate around the input shaft 1, and the axial positioning of the bearing can be realized through a shaft shoulder, a check ring and the like;

the input gear 8 is sleeved on the input shaft 1 through a bearing, and the input gear 8 is axially fixed and circumferentially rotatable;

The double gear 5 is arranged on the double gear shaft 4 through a bearing, the double gear 5 can rotate around the double gear shaft 4, the double gear shaft 4 is fixed in the bearing seat 9, and the axis of the double gear shaft 4 is parallel to the axis of the input shaft 1;

the double gear 5 comprises a right end gear and a left end gear which are coaxially connected, the right end gear of the double gear 5 is meshed with the input gear 8, the left end gear of the double gear 5 is meshed with the output gear 2, the output gear 2 is fixed in the hub shell 3, a through hole is formed in the center of the output gear 2, the input shaft 1 penetrates through the through hole, and the axis of the output gear 2 is coaxial with the axis of the input shaft 1;

in order to improve the stress condition of the components, preferably, the number of the duplex gears 5 is 2 to 4, and the duplex gears are circumferentially uniformly distributed or centrosymmetrically distributed relative to the input shaft 1, as shown in fig. 2;

in practical use, because the size of the internal speed-changing hub is smaller, the size of the duplex gear shafts is limited, the single duplex gear shaft is also in a cantilever structure and is easy to deform, in order to strengthen the rigidity and strength of the duplex gear shafts and meet the requirement of small size, preferably, the duplex gear shafts 4 are all connected at the free ends of the duplex gear shafts by using reinforcing rings 24, as shown in fig. 2, the reinforcing rings 24 are provided with inner holes with the same number as the duplex gear shafts, the free ends of all the duplex gear shafts 4 are inserted into the inner holes corresponding to the reinforcing rings, the other ends of the duplex gear shafts 4 are fixed on bearing seats 9, and the reinforcing rings 24 and axially available check rings of the duplex gear 5 are limited. When fewer duplex gears are arranged, such as 1 or 2 duplex gears are arranged, a plurality of reinforced circular shafts similar to the duplex gear shafts 4 can be added in the bearing seat 9, the free ends of the duplex gear shafts 4 and the free ends of the reinforced circular shafts are inserted into corresponding inner holes of the reinforced rings, and no gears are arranged on the reinforced circular shafts, so that the rigidity and the strength of the structure are only enhanced.

If the input gear 8 is not sleeved on the input shaft 1 but fixed on the input shaft 1, the input shaft 1 always rotates together with the input gear 8, and then always rotates with the duplex gear 5, the output gear 2 and the hub shell 3;

in fig. 1, in order to realize that the input shaft 1 unidirectionally drives the input gear 8 and further unidirectionally drives the hub shell 3, a ratchet mechanism capable of unidirectionally driving is needed between the input shaft 1 and the input gear 8;

for this purpose, as shown in fig. 1, a pawl 6 is disposed between a ratchet seat 7 and an input gear 8, as shown in fig. 10, the pawl 6 is processed with a cylindrical surface 602 and a ratchet 601, and the ratchet 601 of the pawl 6 is matched with a tooth slot 8011 (as shown in fig. 3) of the input gear 8 or a tooth slot 7011 (as shown in fig. 5) of the ratchet seat 7;

the input gear 8 is machined with a tooth slot 8011 (as shown in fig. 3) or a semi-cylindrical hole 8022 (as shown in fig. 4), the input gear 8 with the tooth slot 8011 is identified as 801, the input gear 8 with the semi-cylindrical hole 8022 is identified as 802, and the named semi-cylindrical hole mainly refers to that the machined round hole is not a complete round hole;

the ratchet seat 7 is provided with a semi-cylindrical hole 7022 (as shown in fig. 6), or is provided with a tooth groove 7011 (as shown in fig. 5), the ratchet seat 7 provided with the semi-cylindrical hole 7022 is marked as 702, the ratchet seat 7 provided with the tooth groove 7011 is marked as 701, the ratchet seat 7 is fixed on the input shaft 1, or the ratchet seat 7 and the input shaft 1 are integrated, and the ratchet seat 7 and the input shaft 1 rotate circumferentially together;

As shown in fig. 1, 14 and 15, the ratchet seat 7, the pawl 6 and the input gear 8 form a ratchet mechanism, the semi-cylindrical hole 7022 of the ratchet seat 7 or the semi-cylindrical hole 8022 of the input gear 8 is in clearance fit with the cylindrical surface on the pawl 6, the pawl 6 rotates around the axis of the semi-cylindrical hole, the pawl 6 is provided with a pawl spring 11, the ratchet teeth on the pawl 6 have a tendency to be inserted into the tooth grooves 7011 of the ratchet seat 7 or the tooth grooves 8011 of the input gear 8 under the action of the spring, when the input shaft 1 rotates anticlockwise relative to the input gear 8, the ratchet teeth on the pawl 6 are always embedded in the tooth grooves of the ratchet seat 7 or the input gear 8, the input shaft 1 drives the input gear 8 to rotate anticlockwise through the ratchet seat 7 and the pawl 6, the input gear 8 drives the duplex gear 5 to rotate, and the duplex gear 5 drives the output gear 2 and the hub housing 3 to rotate anticlockwise around the input shaft 1; when the input shaft 1 rotates clockwise relative to the input gear 8, the ratchet teeth of the pawl 6 slide out of the ratchet seat 7 or the tooth grooves of the input gear 8, and the input shaft 1 cannot drive the input gear 8 to rotate, so that unidirectional transmission from the input shaft 1 to the hub shell 3 is realized.

Considering the stress condition of the parts, the processing and mounting process and the like, the ratchet seat 7 can be fixed on the input shaft 1 by adopting different methods, preferably, the ratchet seat 7 is provided with a square hole in the center (as shown in fig. 5), and the square hole is matched with a square journal on the input shaft 1 to transmit power; or preferably, the ratchet seat 7 is provided with a splined hole 707, as shown in fig. 7, and the splined hole 707 is matched with a spline shaft neck on the input shaft; or preferably, the ratchet seat 7 is provided with a round hole, and the ratchet seat 7 is sleeved in the input shaft 1 and fixed on the input shaft by welding; or preferably, the ratchet seat 7 and the input shaft 1 are integrated into one piece, fig. 8 is a cross-sectional view of the integrated input shaft 1, and fig. 9 is a front view of the integrated input shaft 1; or preferably, a round hole is formed in the center of the ratchet seat 7, and the ratchet seat 7 is fixed on the input shaft 1 in an interference fit mode.

The input shaft 1 drives the rotation speed of the hub shell 3, and the rotation speed is related to the number of teeth of each gear, and is generally acceleration transmission in bicycles and is generally deceleration transmission in motor vehicles, and the specific number of teeth of the gears needs to be reasonably determined according to application scenes, speed ratio requirements and structural dimensions.

The following further describes a ratchet mechanism, as shown in fig. 14 and 5, when the ratchet seat 7 is machined with a tooth slot 7011, and the pawl 6 is located outside the tooth slot 7011, the ratchet mechanism is simply called an external engaged ratchet, and the input gear 8 is machined with a semi-cylindrical hole 8022 (as shown in fig. 4), and the semi-cylindrical hole 8022 of the input gear 8 is in clearance fit with the cylindrical surface on the pawl 6.

As shown in fig. 15 and 3, when the input gear 8 is machined with a tooth slot 8011, the pawl 6 is located inside the tooth slot 8011, the ratchet mechanism is simply called an internal engaged ratchet, and at this time, the ratchet seat 7 is machined with a semi-cylindrical hole 7022 (as shown in fig. 6), and the semi-cylindrical hole 7022 of the ratchet seat 7 is in clearance fit with a cylindrical surface on the pawl 6.

As shown in fig. 1, 5 and 14, in the external engaged ratchet, the ratchet seat 7 is provided with a tooth groove 7011, the pawl 6 is positioned at the outer side of the tooth groove 7011, a semi-cylindrical hole 8022 on the input gear 8 is in clearance fit with a cylindrical surface 602 on the pawl 6, preferably, the pawl 6 axially extends out of the input gear 8, a pawl spring 11 is mounted at the part of the pawl 6 extending out of the input gear 8, and the ratchet teeth on the pawl 6 have a tendency to be inserted into the tooth groove 7011 on the ratchet seat 7 under the action of the spring.

Preferably, the pawl spring 11 is a circular spring ring 111 with an opening as shown in fig. 16 and 17, two ends of the spring ring 111 are hooked, the bent hooks are inwards, the spring ring 111 has a tendency to shrink inwards, the spring ring 111 presses the pawl from outside to inside, so that the pawl 6 has a tendency to rotate inwards, the inwards bent hooks can limit the rotation of the spring ring 111 relative to the pawl 6 after touching the pawl 6, because the spring ring 111 does not always rotate together with the ratchet seat 7, only when the input shaft 1 rotates anticlockwise, the ratchet teeth on the pawl 6 are provided with tooth grooves 7011 inserted into the ratchet seat 7, and the spring ring 111 and the input gear 8 rotate together with the pawl 6, so that the hooked bent hooks of the spring ring 111 are proper in size and cannot be inserted into the tooth grooves 7011.

Preferably, in the external engagement ratchet, as shown in fig. 11, the ratchet surface at the left end of the pawl 6 is convex, and the axial length of the ratchet surface of the pawl 6 is greater than the axial length of the cylindrical surface of the pawl.

As shown in fig. 1 and 15, in the internal engaged ratchet, the input gear 8 is machined with a tooth slot 8011, the pawl 6 is located at the inner side of the tooth slot 8011, a semi-cylindrical hole 7022 on the ratchet seat 7 is in clearance fit with a cylindrical surface 602 on the pawl 6, the pawl 6 axially extends out of the input gear 8, a pawl spring 11 is mounted at a portion of the pawl 6 extending out of the input gear 8, and the ratchet 601 on the pawl 6 has a tendency to be inserted into the tooth slot 8011 on the input gear 8 under the action of the spring. Preferably, the pawl spring 11 is a spring ring 113 with an opening for outward bending and inward engagement as shown in fig. 18 and 19, the spring ring 113 has a tendency to be opened outward, and the spring ring 113 presses the pawl from inside to outside as shown in fig. 18 and 15, so that the pawl 6 has a tendency to rotate outward. Preferably, the two ends of the spring ring 113 are hooked, the hooks are outwards, and the outwards hooks can limit the rotation of the spring ring relative to the pawl 6. Preferably, in the internal engagement ratchet, as shown in fig. 11, the ratchet surface at the left end of the pawl 6 is convex, and the axial length of the ratchet surface of the pawl 6 is greater than the axial length of the cylindrical surface of the pawl.

In the internal engaged ratchet, as shown in fig. 15, another combination of a pawl and a pawl spring is formed in the input gear 8, the pawl 6 is positioned at the inner side of the tooth slot 8011, a semi-cylindrical hole 7022 on the ratchet seat 7 is in clearance fit with a cylindrical surface on the pawl 6, as shown in fig. 13 and 22, the cylindrical surface at the left end of the pawl 6 protrudes, the cylindrical surface of the pawl 6 axially extends out of the input gear 8, and a pawl spring 11 is arranged on the cylindrical surface of the pawl 6 extending out of the input gear 8.

The cylindrical surface of the pawl 6 extending out of the input gear 8 is machined with a bevel 603 (as shown in fig. 12) that deflects the spring force at the contact point of the spring ring 114 and the cylindrical surface away from the center of the cylindrical surface, which spring force tends to rotate the pawl 6 outwardly, and the ratchet teeth 601 of the pawl 6 tend to be inserted into the tooth slots 8011 on the input gear 8.

Preferably, the pawl spring 11 is a spring ring 114 for inward engagement with an opening, as shown in fig. 20 and 21, the spring ring 114 has a tendency to retract inward, and the spring ring 114 presses the cylindrical surface of the pawl 6 from the outside to the inside.

In order to limit the rotation of the spring ring 114 around the axis, preferably, as shown in fig. 21, two ends of the spring ring 114 are hooked, the bent hooks are inwards, the input shaft 1 is provided with grooves 705 (as shown in fig. 8 and 20), hooked spring wires at the ends of the spring ring 114 are clamped into the grooves 705 (as shown in fig. 20), the tightness degree of the hooked spring wires clamped into the grooves 705 influences the elasticity of the spring ring 114, the strength is required to be reasonably selected according to the smoothness degree of rotation of the pawl, in fig. 20, the ratchet seat 7 and the input shaft 1 are integrated, fig. 9 is a front view of the input shaft when the ratchet seat 7 and the input shaft 1 are integrated, the number of the pawls 6 in fig. 20 is 3, and in particular implementation, the number of the pawls 6 can be reasonably selected according to factors such as structural size, stress requirements and the like.

To limit the axial movement of the pawl 6 and the spring fitted over the pawl 6, as shown in fig. 22, 8 and 9, the input shaft 1 is formed with a ring groove 704 (when the ratchet seat 7 and the input shaft 1 are not integrally formed but are separately formed, the ring groove 704 is formed in the ratchet seat 7), the spring ring 114 is engaged with the ring groove 704, and the spring ring 114 and the bearing fitted to the inner hole of the input gear 8 together limit the axial movement of the pawl 6.

When the ratchet seat 7 and the input shaft 1 are separately processed, the ratchet seat 7 is fixed on the input shaft 1, and the trend of inserting the ratchet 601 of the pawl 6 into the tooth groove 8011 of the input gear 8 under the action of the spring ring 114 can be realized according to the principle, and the difference is that when the ratchet seat 7 and the input shaft 1 are separately processed, the semi-cylindrical hole 7022, the annular groove 704 and the groove 705 are processed on the ratchet seat, the part processing technology is simple, and the part strength is reduced; when the ratchet seat 7 and the input shaft 1 are integrated, the ratchet seat function is fused to the input shaft, so that the semi-cylindrical hole 7022, the annular groove 704 and the groove 705 are machined on the input shaft, the machining process of parts is relatively complex, and the strength of the parts can meet the requirements more easily.

In consideration of stress distribution, structural size, spring force position and other factors of the pawls, in order to improve stress conditions, the number of the pawls 6 is generally 2 to 4, preferably, the pawls 6 are uniformly distributed circumferentially around the axis of the input shaft, the number of ratchets on the pawls 6 is generally 1 to 5, and the larger the number of the ratchets is, the larger the transmission torque is relatively larger.

To further explain the connection of the output gear 2 and the hub shell 3, as shown in fig. 1, the hub shell 3 is machined with a connecting inner hole for fixing the output gear 2, the output gear 2 is fixed in the connecting inner hole of the hub shell 3, the inner hole is coaxial with the axis of the hub shell 3, preferably, one end of the output gear 2 is machined with a cylinder, the cylinder of the output gear 2 is pressed into the connecting inner hole of the hub shell 3 through interference fit, and the cylinder of the output gear 2 can increase friction force and driving torque between the hub shell 3 and the output gear 2 by using knurling and other processes; preferably, as shown in fig. 23, an external thread 201 is machined on a cylindrical surface at one end of the output gear 2, an internal thread is machined on a connecting inner hole of the hub shell 3, the output gear 2 is screwed into a screw hole of the hub shell 3, the screwing direction of the thread is the same as the power input direction of the input shaft 1, and the output gear 2 is firmly fixed in the hub shell 3 when being driven by foot; preferably, the output gear 2 is integrally fixed in the hub shell 3 as an insert of the hub shell 3 during the die casting of the hub shell 3; preferably, in order to increase the reliability of fixing the output gear 2 in the hub shell 3, as shown in fig. 24, a threaded hole is machined on the left end face of the output gear 2, and the screw 211 is screwed into the corresponding threaded hole on the end face of the output gear 2, so that due to structural limitation, the size of the threaded hole is smaller, and the connection between the output gear 2 and the hub shell 3 is reinforced mainly by matching with other connection modes, thereby increasing the connection reliability.

In order to improve the integration level and facilitate the use, the installation and the maintenance, the invention can integrate the brake mechanism into the hub, as shown in fig. 25 and 26, the inner speed-changing hub also comprises a left brake block 18, a right brake block 22, a brake fixed shaft 19, a rocker arm 20 and a brake rotating shaft 21, the above components and the hub shell 3 together form the brake mechanism, the brake mechanism is integrated into the hub, the brake fixed shaft 19 is fixed on the fork 10, the fork 10 is provided with a rotating shaft inner hole 274, the brake rotating shaft 21 is in clearance fit with the rotating shaft inner hole 274 of the fork 10, the brake rotating shaft 21 is provided with a section of the brake rotating shaft 21 which is installed in the rotating shaft inner hole 274 of the fork 10 (as shown in fig. 28 and 29), one end of the brake rotating shaft 21 is fixed with the rocker arm 20, when the rocker arm 20 rotates under the action of the tensile force of a brake wire, the rocker arm 20 drives the brake rotating shaft 21 to rotate, the brake rotating shaft 21 and the brake block contact part is a square shaft, when the brake rotating shaft 21 rotates, the brake rotating shaft 18 and the brake block 22 rotate around the brake fixed shaft through the square shaft, so that the left brake block 18 and the right brake block 22 rotate around the brake fixed shaft, and the brake rotating shaft 20 rotate around the brake fixed shaft, so that the left brake rotating shaft 18 and the brake rotating shaft 3 and the brake rotating around the brake rotating wire, and the brake rotating shaft 3 are not compressed, and the brake rotating the shell 3 or the brake rotating, and the brake rotating body 3.

Example two

As shown in fig. 27 and 1, the front wheel drive bicycle comprises a front wheel set 25, a pedal 26, a front fork 27, a handle 28, a frame 29, a seat cushion 30, a backrest 31, a rear fork 32 and a rear wheel set 33, wherein the front wheel set 25 comprises spokes, a rim and the inner speed changing hub, the spokes are used for connecting and fixing the rim and the hub shell 3, a bearing seat 9 is fixed on the front fork 27, the front wheel set is arranged on the front fork 27 through the bearing seat 9, the pedal 26 is fixed on two ends of an input shaft 1 of the inner speed changing hub, the front fork 27 is connected with the handle 28 and is arranged on the frame 29 through a bearing, the seat cushion 30 is arranged on the frame 29, the backrest 31 is arranged behind the seat cushion 30, the rear fork 32 is arranged behind the frame 29, and the rear wheel set 33 is arranged on the rear fork 32;

when the pedal 26 is stepped on, the input shaft 1 rotates, the rotation speed of the input shaft 1 drives the hub shell 3 to rotate after being changed by the internal speed changing hub, the wheel rim is fixedly connected with the hub shell 3 through spokes, the whole front wheel set 25 rotates along with the stepping of the pedal 26, the front fork 27 is mounted on the frame through a bearing, and the front wheel set 25 drives the bicycle to move when rotating.

Preferably, as shown in fig. 28, 29 and 30, the front fork 27 is shaped like a single-sided fork frame of a conventional front fork, a through hole 272 is formed at the lower portion of the front fork, the input shaft 1 passes through the through hole 272, bolt holes 273 for mounting bolts are arranged around the through hole 272, and the bearing housing 9 is fixed to the front fork 27 by bolting.

Preferably, as shown in fig. 29, in order to reduce the weight, the shaft of the front fork 27 has a hollow structure, the lower hollow structure is opened to the left, the upper hollow structure is opened to the right, and the position and the opening direction of the hollow structure are comprehensively considered with respect to the mold release form and the appearance and strength requirements of the product, so as to be suitable for the die-casting mold release.

Preferably, as shown in fig. 29, the front fork 27 has a vertical bore 271 at its upper end, the vertical bore 271 being used to secure a standpipe, which is used to attach a handle and mounting bearings. In a common bicycle, the vertical tube and the fork frame are generally fixed by welding to form a front fork whole, and the vertical inner hole 271 is processed at the upper part of the front fork 27, so that the vertical tube can be fixed by riveting and the like.

Preferably, as shown in fig. 29, the front fork 27 is a die-cast molding member, and preferably, the brake fixed shaft 19 is used as an insert of the front fork 27 and is integrally fixed in the front fork 27 when the front fork 27 is die-cast.

The crosspiece of the frame 29 is similar to the crosspiece on a tripod of a common bicycle, a rear fork is fixed at the rear part of the crosspiece of the frame 29 at the upper part of the tripod of the common bicycle, and the crosspiece, the rear fork and the like form the whole frame together.

Preferably, as shown in fig. 31, the crosspiece of the frame 29 has a square cross section 291, on which the seat cushion 30 is mounted, and the square cross section allows for the seat cushion 30 to rest on the crosspiece more smoothly, so that the seat cushion is less likely to rotate about the crosspiece, and is more reliable and safer than a crosspiece having a circular cross section.

Preferably, as shown in fig. 31, the seat cushion 30 is provided with a locking clip 292, the locking clip 292 being engaged with the rail, the seat cushion 30 being movable along the rail to a position generally compatible with height and leg length to clamp the locking clip 292.

Preferably, as shown in fig. 32, the crosspiece of the frame 29 is a half square section 293, the contact portion of the crosspiece and the seat cushion 30 is a plane, and the cross section of the crosspiece matched with the locking surface of the clip is an arc surface, so that the seat cushion 30 is stably placed, structural stress, product manufacturing, clip locking and the like are facilitated, and as shown in fig. 32, the clip corresponding to the half square section 293 is a locking clip 294.

Preferably, the locking clip resembles a quick release clip for a public bike saddle tube.

Preferably, as shown in fig. 27, the rail of the frame is provided with a backrest 31, the backrest 31 is arranged behind the seat cushion 30, the backrest 31 is provided with a locking clamp which is sleeved in the rail, and the backrest 31 and the seat cushion 30 can move along the rail together to clamp the locking clamp after moving to a proper position.

Claims

1. The internal speed-changing hub is characterized by comprising an input shaft, an output gear, a hub shell, a duplex gear shaft, a duplex gear, a pawl, a ratchet seat, an input gear, a bearing seat, a fork frame and a pawl spring, wherein the bearing seat is fixed on the fork frame, a bearing hole is formed in the bearing seat, the input shaft is arranged in the bearing hole of the bearing seat through a bearing, the input shaft rotates circumferentially and is axially fixed, and the ratchet seat is fixed on the input shaft or is integrated with the input shaft;

the ratchet seat is provided with a half cylinder hole or a half cylinder hole, the half cylinder hole of the ratchet seat or the half cylinder hole of the input gear is in clearance fit with a cylindrical surface on a pawl, the pawl rotates around the axis of the half cylinder hole, the pawl is provided with a pawl spring, and a ratchet tooth on the pawl has a tendency of being inserted into the tooth groove of the ratchet seat or the tooth groove of the input gear under the action of the pawl spring;

2. An internal transmission hub as defined in claim 1, wherein said tandem gear shafts are joined at their free ends by reinforcing rings having the same number of bores as the tandem gear shafts, and wherein the free ends of all the tandem gear shafts are inserted into the corresponding bores of the reinforcing rings.

3. An internal gear hub as claimed in claim 1 wherein the ratchet wheel seat is formed with a tooth socket and the input gear is formed with a semi-cylindrical hole, the pawl is located on the outside of the tooth socket, the semi-cylindrical hole on the input gear is in clearance fit with the cylindrical surface on the pawl, the pawl extends axially beyond the input gear, a pawl spring is mounted on the portion of the pawl extending beyond the input gear, and the ratchet teeth on the pawl have a tendency to be inserted into the tooth socket on the ratchet wheel seat under the action of the pawl spring.

4. The internal gear hub of claim 1, wherein the input gear is provided with a tooth socket, the ratchet seat is provided with a semi-cylindrical hole, the pawl is positioned at the inner side of the tooth socket, the semi-cylindrical hole on the ratchet seat is in clearance fit with the cylindrical surface on the pawl, the cylindrical surface at the left end of the pawl is convex, the cylindrical surface of the pawl axially extends out of the input gear, the pawl spring is arranged on the cylindrical surface of the pawl extending out of the input gear, and the cylindrical surface of the pawl extending out of the input gear is provided with an inclined surface.

5. The internal shift hub of claim 4, wherein said pawl spring is a circlip with openings, said spring having a tendency to retract inwardly, said spring pressing the pawl from the outside inwardly causing the ratchet teeth on the pawl to have a tendency to insert into the tooth spaces on the input gear, said ratchet seat being machined with a ring groove into which said spring snaps.

6. An internal transmission hub as claimed in claim 1, wherein said output gear is integrally secured in the hub shell as an insert in the hub shell during die casting of the hub shell.

7. The internal speed changing hub as claimed in claim 1, further comprising a left brake plate, a right brake plate, a brake dead axle, a rocker arm and a brake rotating shaft, wherein the brake dead axle is fixed on the fork frame, the fork frame is provided with a rotating shaft inner hole, the brake rotating shaft is in clearance fit with the rotating shaft inner hole of the fork frame, one section of the brake rotating shaft is arranged in the rotating shaft inner hole of the fork frame, one end of the brake rotating shaft is fixed with the rocker arm, when the rocker arm rotates under the action of the pulling force of the brake wire, the rocker arm drives the brake rotating shaft to rotate, the part, which is contacted with the brake plate, is a square shaft, the section of the brake rotating shaft is approximately rectangular, and when the brake rotating shaft rotates, the brake rotating shaft drives the left brake plate and the right brake plate to rotate around the brake dead axle through the square shaft, so that the left brake plate and the right brake plate are expanded and compress the hub shell, and the hub shell is decelerated or stopped rotating, and the left brake plate and the right brake plate are pulled with a spring when the brake wire does not exert pulling force.

8. The front wheel drive bicycle comprises a front wheel set, pedals, a front fork, a handle, a frame, a seat cushion, a backrest, a rear fork and a rear wheel set, and is characterized in that the front wheel set comprises spokes, a rim and the inner speed-changing hub according to any one of claims 1-7, the spokes are used for connecting and fixing the rim and a hub shell, the front wheel set is installed on the front fork through bearing blocks, the bearing blocks are fixed on the front fork, the pedals are fixed at two ends of an input shaft of the inner speed-changing hub, the front fork is connected with the handle and is installed on the frame through bearings, the seat cushion is installed on the frame, the backrest is installed behind the seat cushion, the rear fork is positioned behind the frame, and the rear wheel set is installed on the rear fork.

9. A front wheel drive bicycle as defined in claim 8, wherein the cross member of the frame is square in cross section, the cross member having a seat cushion mounted thereon, the seat cushion having a locking clip which is received in the cross member and the seat cushion being movable along the cross member to a position to clamp the locking clip to secure the seat cushion.

10. The front wheel drive bicycle of claim 8, wherein the shaft of the front fork has a hollow structure, the lower hollow structure is open to the left, the upper hollow structure is open to the right, and the upper end of the front fork has a vertical inner hole.