CN2120762U - Stepless speed changer for bicycle - Google Patents

Abstract

The utility model discloses a stepless speed changer for a bicycle, which is provided with a pivoted arm that is fixed with a flywheel and can be rotated around an axle shaft; a friction wheel which is embedded between inner and outer wheels is driven by a disk structure having a radial groove; a friction torque is moved in radial direction in a wheel hub through adjusting the interstice between the inner wheels, and the purpose of adjusting speed ratio can be achieved. The utility model solves the complicated problem of the existing speed changer appearance, and the adjustment range of the speed ratio is enhanced.

Description

Stepless speed changer for bicycle

The utility model relates to a kind of transmission system that changes the bicycle transmitting ratio, especially can realize infinite variable speed change-speed box.

At present, known bicycle speed-varying unit has a variety of, but there is certain shortcoming in various degree, as a kind of change-speed box that is formed by stacking by several gears in the outer change-speed box, its speed-change process is realized with different gear meshing by chain, chain and other gear fall chain in the engagement process again easily during speed change, and because the friction that the distortion of chain side direction produces has reduced its service life, this change-speed box inevitably will be used chain tension adjusting device.The another kind of form of outer change-speed box is combined to form gear by several gear pieces, it realizes changing transmitting ratio by the motion segment radius of circle that changes each gear piece and chain engages position, though it has eliminated the side direction distortion of chain, but still have surface structure complexity and the shortcoming that must be used chain tension adjusting device.Known a kind of internal speed changer is to be made by the principle of epicyclic gear transmission at present in addition, it has the advantage that surface structure is simple, ratio coverage uses chain tension adjusting device greatly and not, but because gear is limited, the spacing of each grade is increased, cause the shortcoming of bicyclist's traveling comfort difference.Above existing change-speed box is step change transmission.

The purpose of this utility model provides a kind of bicycle speed-varying unit, and it not only has gear ratio change in a big way, and has realized stepless change.

Bicycle toric transmission of the present utility model has and is sleeved on the axletree rotationally and the fixing pivoted arm that can rotate synchronously with flywheel of outer end and flywheel, the other end of pivoted arm is the disk-shaped structure that is provided with one group of radial groove, one end vertically arranged little with disk arranged in each chute, little axle can move radially along chute, make the shape of little axle self limit moving axially of it by a kind of known mode, the other end at little axle turns and is equipped with moving axially at least one disk friction wheel, the axletree of friction wheel partly be embedded in and the fixed cover of fixed axle and and circumferentially fixing at least one clamping sleeve of axletree between, have in the outside of clamping sleeve one with the accent wheel of axletree axial location, transfer wheel and contiguous clamping sleeve to spin.It changes the axial spacing of clamping sleeve and fixed cover, and its action is to become to handle by being connected in the speed change of transferring on the wheel.The axletree far away of friction wheel partly is embedded between two outer clip wheels at least, and to the direction motion of closing up, outer clip wheel and spring are installed in the sliding sleeve and together circumferentially are fixed on the wheel hub outer clip wheel, but can move axially along wheel hub by spring control.Be equipped with by common form in the both sides of axletree and make steel ball and cooresponding bowl, axle bumper, locknut and end cap of transferring wheel and pivoted arm to rotate relative to axletree and wheel hub, the resistance that they reduce pivoted arm, transfer wheel and wheel hub to rotate, and make pivoted arm, accent wheel, the relative axletree axial location of wheel hub.

Advantage of the present utility model is: surface structure is simple, and ratio coverage is bigger, maintain easily and ride in particularly in the speed-change process traveling comfort good, realized stepless change.

Below in conjunction with drawings and Examples the utility model is described further: wherein

Fig. 1 is the axial longitudinal section of bicycle toric transmission of the present utility model;

Fig. 2 is the axial view of pivoted arm, little shape shaft that wherein has two friction wheels and to remove to see behind the friction wheel and the radial groove on pivoted arm;

Fig. 3 is the axial longitudinal diagram of pivoted arm;

Fig. 4 is the front elevation of little axle;

Fig. 5 is little axle and birds-eye view;

Fig. 6, Fig. 7 are the axial longitudinal diagram and the drawings in side sectional elevation of sliding sleeve, have shown the position of outer clip wheel and keyway thereof.

According to Fig. 1, bicycle toric transmission of the present utility model has an axletree 29, the pivoted arm 17 that rotates around axletree 29 is arranged in this outside of 29, one end and the flywheel of pivoted arm 17 spin fixing, flywheel is a long and two-short dash line part among the figure one, the other end of pivoted arm 17 be provided with radial groove 17 ' disk-shaped structure (as Fig. 2,3), present embodiment have three radial grooves 17 ', chute 17 ' in an end of little axle 26 is installed, little axle 26 can be along the chute radial motion, by the shape limitation of little axle 26 self it chute 17 ' in move axially (as Fig. 4,5).The other end at little axle 26 turns and is equipped with moving axially a disk friction wheel 23, present embodiment adopts on each little axle 26 and adorns a friction wheel 23, nearly axletree 29 parts of friction wheel 23 are embedded between the fixed cover 25 and clamping sleeve 22 that is enclosed within on the axletree 29, wherein fixed cover 25 is fixed on the axletree 29, clamping sleeve 22 endoporus are helicitic texture, it can move axially on axletree 29, but circumferentially fixing by key 24 and axletree 29.The one accent wheel 5 that can rotate on axletree 29 and be axially fixed is arranged in the outside of clamping sleeve 22, its clamping sleeve 22 ends are helicitic texture, and screw with the screw thread of clamping sleeve 22, its outer end integrated disc portions has the shift cable 4 of being fixed by screw 2, and can be rotated around axletree 29 by shift cable 4 controls.Axletree far away 29 parts of friction wheel 23 are embedded in 11 of one group of outer clip wheels, every group of outer clip wheel has two at least, wherein the outer clip wheel of a side is positioned in the sliding sleeve 12 by jump ring 9, the outer clip wheel of opposite side is positioned in the sliding sleeve 12 by belleville spring 13, one end of belleville spring is against on the sliding sleeve 12, the other end is against on the outer clip wheel 11, the direction of belleville spring 13 power is directions that two outer clip wheels 11 are closed up, outside two, all have keyway on the clip wheel 11, have corresponding slotted hole on the sliding sleeve 12, two outer clip wheels 11 and the positioning key 10 that sliding sleeve 12 is all taken turns and wheel hub 14 is fixed are circumferentially located and are rotated synchronously with wheel hub 14.Outer folder 11, sliding sleeve 12 all can move axially (seeing Fig. 6,7) along positioning key 10.Two groups of steel balls and two axle bumpers 18 are arranged between pivoted arm 17 and axletree 29, have a locating bush 27 to make two axle bumpers 18 keep a determining deviation 18 of two axle bumpers, they make pivoted arm 17 relative to axletree 29 axial location and the resistance when reducing pivoted arm 17 and rotating.There are one group of steel ball and an axle bumper 16 to make wheel hub 14 and pivoted arm 17 locate and reduce the resistance of wheel hub 14 rotations mutually at pivoted arm 17 and 14 of wheel hubs.At end cap 6 with transfer 5 on wheel to have one group of steel ball and axle bumper 20 to make end cap 6 and wheel hub 14 location and restriction transfer moving axially of wheel 5, reduced the resistance that end cap 6 rotates simultaneously.There are one group of steel ball and an axle bumper 19 to make the resistances of transferring wheel 5 axial location and minimizing to transfer wheel 5 to rotate at accent wheel 5 and 29 of axletrees.

The transmission process of present embodiment is achieved in that when flywheel drives pivoted arm 17 rotations, be contained in pivoted arm radial groove 17 ' interior little axle 26 also rotates thereupon, the friction wheel 23 that rotates around little axle 26 on the little axle 26 also moves with little axle 26, because nearly axletree 29 parts of friction wheel 23 are embedded in 25 of clamping sleeve 22 and fixed covers, rotate around little axle 26 when the friction force between them makes friction wheel 23 with steamboat 26 motions.Because axletree far away 29 parts of the friction wheel 23 that rotates are embedded in 11 of two outer clip wheels that compressed by belleville spring 13, therefore the effect of friction wheel 23 and 11 friction force of outer clip wheel, outer clip wheel 11 is rotated in the same way with friction wheel 23, because outer clip wheel 11 and sliding sleeve 12 are circumferentially located with wheel hub 14, so wheel hub 14 rotates in the same way with friction wheel 23, realized the purpose that drive wheels is rotated.

When the speed-change process of present embodiment is achieved in that in riding raising speed, pulling shift cable 4 makes transfers wheel 5 to rotate, owing to transfer wheel 5 and clamping sleeve 22 to screw, and clamping sleeve 22 circumferentially is fixed on the axletree 29, the accent wheel 5 that therefore rotates make clamping sleeve 22 along axletree 29 axially to moving away from the direction of fixed cover 25.Because the effect of belleville spring 13 pressure is extruded to nearly axletree 29 directions the friction wheel 23 of rotation.Till compressing again with clamping sleeve 22 and fixed cover 25, little axle 26 also with friction wheel 23 along the radial groove 17 of pivoted arm 17 ' slide into apart from axletree 29 nearer positions.Friction wheel 23 that rotates this moment and the radius of turn of the radius of turn of outer clip wheel 11 contacts site greater than friction wheel 23 and clamping sleeve 22 and fixed cover 25 contacts site, so the former speed is higher than the latter's speed, realized raising speed.Handling shift cable 4 during reduction of speed rotates accent wheel 5 round about, clamping sleeve 22 is drawn close to fixed cover 25 directions, the friction wheel 23 that rotates is extruded to the direction away from axletree 29 and moves, darker is embedded in the outer clip wheel 11, little axle 26 also with friction wheel 23 along the radial groove 17 of pivoted arm 17 ' move to direction away from axletree 29.The radius of turn that reaches friction wheel 23 and outer clip wheel 11 contacts site when the position of moving is during less than the radius of turn of friction wheel 23 and clamping sleeve 22 and fixed cover 25 contacts site, therefore the speed at position realized the purpose of reduction of speed less than the rub speed at position of the latter because the former rubs.

This speed-change process is to transfer the rotation of wheel 5 clamping sleeve 22 to be changed gradually with 25 distances of fixed cover realize by control, and therefore whole speed-change process is excessively also to remain on the interior arbitrary position of variable range gradually, has realized infinite variable speed purpose.

Claims (3)

1, a kind of bicycle toric transmission, the both sides that are included in axletree can be with respect to the steel ball and the cooresponding axle bowl of axletree and wheel hub rotation by the speed-changing mechanism that makes of common form installation, axle bumper, locknut and end cap, it is characterized in that on axletree suit an outer end and the fixing pivoted arm of flywheel rotationally, the inner of pivoted arm is a disk-shaped structure of establishing one group of radial groove, the end of little axle that the slip of one installation vertical with the disk card is arranged in each chute, make the shape of little axle self limit moving axially of it by a kind of known mode, rotatable and at least one disk friction wheel can be housed with moving axially at the other end of little axle.The nearly axletree of friction wheel partly be embedded in the fixed cover of fixed axle and with the too tight inner room of axletree axial location, compress the magnetic outside spin one with the accent wheel of axletree axial location, on the accent wheel, be connected to one and can make the shift cable of transferring wheel to rotate, the axletree far away of friction wheel partly is embedded between two outer clip wheels at least, outer clip wheel group and spring be installed in the sliding sleeve by spring control to the direction motion of closing up and together be arranged in vertically on the wheel hub key and sliding sleeve and outside keyway on the clip wheel circumferentially be positioned on the wheel hub.

2, by the described bicycle toric transmission of claim 1, a side that it is characterized in that being contained in the outer clip wheel group in the sliding sleeve have the sliding sleeve wall and outside stage clip between the clip wheel, opposite side is located by jump ring.

3,, it is characterized in that described stage clip is one group of belleville spring by the described bicycle toric transmission of claim 2.

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