CN100467343C - Gear shifting apparatus and bicycle incorporating same - Google Patents

Abstract

A gear-shifting apparatus is provided which easily returns a derailed chain to engagement with a tension and/or guide pulley when the chain comes off the respective pulley due to a gear-shifting operation, and enables a gear-shifting operation to be performed when a gear-shifting is halted or is rotating backward. A derailer includes an arm which supports a tension pulley and a pulley support member which supports a guide pulley. The arm is provided with engagement recovery-guiding parts for causing respectively derailed parts of a chain, which are derailed from the orbital plane of the tension pulley, to engage with the tension pulley. The pulley support member is provided with a first extending part and a second extending part for the purpose of causing derailed parts of a chain; which has been derailed from the orbital plane of the guide pulley, to engage with the guide pulley.

Description

The bicycle that is used for the transmission system of bicycle and comprises this transmission system

The cross reference of related application

According to 35 USC 119, the present invention requires the preceence of Japanese patent application No.2004-249311 (applying date is on August 27th, 2004) and Japanese patent application No.2004-249312 (applying date is on August 27th, 2004).Each theme of these priority texts is incorporated herein by reference.

Technical field

The present invention relates to a kind of transmission system and a kind of bicycle that comprises this device that is used for bicycle.More particularly, the present invention relates to a kind of transmission system that uses the chain type, this transmission system makes chain be converted to another sprocket wheel from a sprocket wheel.

Background technology

An example of the known transmission system that is used for bicycle is disclosed in the open Official Journal No.2004-155280 of Japanese Patent, this known system comprises drive sprocket, this drive sprocket is connected with bent axle by free-wheel clutch, drives this drive sprocket simultaneously.The known transmission system of the document also comprises: by the chain wheel set that a plurality of speed-changing chains constitute, this chain wheel set is connected with the output shaft that is used for drive rear wheels; Chain, this chain hang on drive sprocket and one of them speed-changing chain; And speed-changing mechanism.Speed-changing mechanism comprises: derailer (derailer) arm, be used for rotatably mounted guide pulley, and this guide pulley is used for the selected speed-changing chain of chain guiding; And arm, being used for rotatably mounted tension pulley block, this tension pulley block is used for applying tensile force to chain.When guide pulley and tension pulley block when the center axial direction of derailer axle moves, chain converts selected speed-changing chain to from current speed-changing chain.Therefore carry out variable speed operation.

Preferably no matter how the running state of bicycle can both carry out variable speed operation.For example, move (under the state of cyclist under the bicycle) backward even or when bicycle stops, can both carry out variable speed operation fast even wish when bicycle by the rotation forward of bent axle.This feature will help to improve the operating characteristic of bicycle.Particularly in cycling, when the track athlete competes for speed, make the track athlete have more multimachine can carry out speed change and will cause better competition result.

But, when not rotating forward, speed-changing chain (comprises situation that speed-changing chain rotates backward when bicycle moves backward and the situation that speed-changing chain stops when bicycle stops), make guide pulley towards center axial direction (hereinafter being called " axial direction ") motion if carry out variable speed operation, a part of chain that hangs over so on the guide pulley in axial direction moves with guide pulley.On the contrary, a part of chain that hangs on one of them speed-changing chain does not in axial direction move.Therefore, in some cases, the portion of chain that hangs on the guide pulley may break away from guide pulley, perhaps derails from guide pulley.If bent axle is rotated forward, chain is in make drive sprocket and speed-changing chain all forward under such a case of rotation, in some cases, the derailing of chain part may be stuck between guide pulley and the derailer arm. and in other cases, the derailing of chain part can be positioned at the guide pulley next door and in the radial direction inboard of the most peripheral end of guide pulley.This makes the derailing of chain partly be difficult to mesh again with guide pulley.

In addition, when speed-changing chain rotated backward, if the rotative speed of speed-changing chain is higher or be in equivalent situation, the part of chain may be stuck between guide pulley and one of them speed-changing chain.When the part of chain is stagnated like this, the easier disengaging guide pulley of chain.

And, in the time of in making the derailing part be in to handle with the guide pulley ingear once more, if obstacle hindered the derailing part along it with the moving of the path that moves when the step that forms by the projection of the path of motion being protruded from the derailing part (for example as), rapidity with the engagement of guide pulley is partly returned in the derailing that reduces chain.In addition, make derailing part and guide pulley ingear reliability reduction once more.

And if carry out variable speed operation in the process that speed-changing chain stops when bicycle stops or being in equivalent state, so owing to following reason, chain may break away from guide pulley at the part place of the tension pulley block that guides chain.When variable speed operation makes guide pulley and tension pulley block when center axial direction (hereinafter being called " axial direction ") moves, currently on the tension pulley block part of portion of chain at the guiding chain at tension pulley block top, in axial direction move with tension pulley block.On the contrary, current portion of chain motion in axial direction hardly at the drive sprocket top.And chain stops.Like this, chain breaks away from tension pulley block.When making bent axle rotate forward under this state, and when therefore drive sprocket and speed-changing chain rotate forward, in some cases, this chain derailing part that has broken away from tension pulley block will be stuck between tension pulley block and the arm.In other cases, derailing part will be stuck in the sidepiece of tension pulley block and in axial direction between the inside part of tension pulley block outermost.In these cases, be difficult to make the derailing part to mesh again with tension pulley block.

Consider foregoing problems and make the present invention.

The purpose of this invention is to provide a kind of transmission system, even this transmission system also can more easily make the derailing of chain partly return and guide pulley ingear state when making chain break away from the orbit plane of guide pulley owing to variable speed operation, even and this transmission system when speed-changing chain does not rotate forward, (comprise the situation that speed-changing chain rotates backward) and also can carry out variable speed operation.

It is the part count that prevents transmission system owing to providing the engagement recovery device to increase to transmission system that the present invention also has a purpose, and reduces the cost of transmission system.

It is to make transmission system miniaturization in axial direction that the present invention also has a purpose.

It is to make the miniaturization in axial direction of engagement recovery device that the present invention also has a purpose, therefore makes the transmission system miniaturization, and by using this engagement recovery device to increase the rigidity of the arm of supporting tension pulley block.

It is to improve to make the derailing of chain partly return rapidity and the reliability with guide pulley ingear state that the present invention also has a purpose.

It is to want to make transmission system miniaturization in axial direction that the present invention also has a purpose, and can carry out level and smooth speed change simultaneously.

The present invention also has a purpose to provide a kind of transmission system, when variable speed operation makes that chain breaks away from tension pulley block, this transmission system makes the derailing chain return and tension pulley block ingear state at an easy rate, therefore, when speed-changing chain stopped not rotate forward with speed-changing chain, this transmission system also can carry out new variable speed operation.

It is the rigidity that increases arm that the present invention also has a purpose, makes the derailing of chain partly return and tension pulley block ingear state more reliably simultaneously.

It is to make the derailing part return and tension pulley block ingear state more reliably that the present invention also has a purpose, makes that simultaneously the weight of derailer arm is lighter.

It is to carry out variable speed operation at an easy rate that the present invention also has a purpose.

A first aspect of the present invention relates to a kind of transmission system, and it comprises: a plurality of speed-changing chains, and these speed-changing chains are in axial direction arranged; And mapping device, be used for making chain be transformed into another from a sprocket wheel at a plurality of speed-changing chains in response to variable speed operation.Mapping device comprises the pulley bearing parts, the rotatably mounted guide pulley of these pulley bearing parts, and chain will hang on this guide pulley, and the motion in axial direction by variable speed operation of these pulley bearing parts.For transmission system, the guide pulley guiding hangs over the chain on the sprocket wheel of having selected from a plurality of speed-changing chains.In transmission system, provide the engagement recovery device on the pulley bearing parts, be used for making the chain derailing part and the engagement of this guide pulley of derailing from the orbit plane of guide pulley.The engagement recovery device comprises first extendible portion and second extendible portion.First extendible portion and second extendible portion are in axial direction arranged left and to the right with respect to orbit plane, and in axial direction and along the direction on deorbit plane are extended.Each extendible portion guides the derailing part that has arrived on this extendible portion as follows, that is, because the tensile force on the chain, the derailing part is slided on this extendible portion, and towards the orbit plane motion, meshes with guide pulley then.

In the transmission system of first aspect present invention, constitute first extendible portion of engagement recovery device and the derailing part that the following respectively following mode of second extendible portion guides chain, that is, the derailing of chain part is slided on first extendible portion and second extendible portion respectively and is meshed with guide pulley.Even chain when speed-changing chain rotates backward or stops is because the guide pulley plane that de-orbits of in axial direction moving by variable speed operation, no matter guide pulley which lateral movement in axial direction, incite somebody to action all that this thing happens.Therefore, although speed-changing chain rotates forward, can prevent that also the derailing part is stuck between guide pulley and the pulley bearing parts or the generation equivalent situation.This makes chain to move.Therefore, even for example carry out variable speed operation when speed-changing chain rotates backward, 1 on chain also will can not be stuck in (in other words, chain can not stagnated) between one of them speed-changing chain and the guide pulley.Therefore, when speed-changing chain rotated forward, chain reliably returned and guide pulley ingear state.

The transmission system of second aspect present invention also comprises following structure except comprising the structure identical with the transmission system of first aspect present invention.The pulley bearing parts comprise: retainer is used for rotatably mounted guide pulley; And arm, being used for rotatably mounted tension pulley block, this tension pulley block is supported by retainer, and this tension pulley block applies tensile force to chain.First extendible portion and arm are integrally molded.Second extendible portion comprises spring housing portion, and this spring housing portion is held spring, so that produce spring force, this spring force is used for tension pulley block is pushed against chain.

In the transmission system of second aspect present invention, first extendible portion and second extendible portion provide by using spring housing portion, and this spring housing portion comprises arm and tensioning spring, and they are parts of supporting tension pulley block.This does not need to prepare the special-purpose member that is used to constitute first extendible portion and second extendible portion.

The transmission system of third aspect present invention also comprises following structure except comprising the structure identical with the transmission system of the present invention first or second aspect.A plurality of speed-changing chains are so that the mode to the speed-changing chain with less external diameter is disposed in order towards the axial direction sidepiece from speed-changing chain with big external diameter.First extendible portion and second extendible portion are arranged in the sidepiece of orbit plane, and in axial direction opposite side.Guiding surface in first extendible portion (the derailing part can arrive on this guiding surface) is positioned at such position, promptly compare with the guiding surface (the derailing part can arrive on this guiding surface) in second extendible portion, it is littler from the distance of the rotation centerline of guide pulley.

In the transmission system of third aspect present invention, when guide pulley during towards lateral movement, with the interference of eliminating between first extendible portion and each speed-changing chain.In addition, each speed-changing chain and guide pulley are arranged to closer proximity to each other.

The transmission system of fourth aspect present invention also comprises following structure except comprising the structure identical with the transmission system of the present invention second or the third aspect.When seeing from the side, first extendible portion is arranged to extend to and makes the extendible portion of winning seem the position that overlaps with tension pulley block.First extendible portion width in axial direction is chain width in axial direction no better than.

In the transmission system of fourth aspect present invention, first extendible portion is as the enhancing rib of arm.Therefore, the rigidity of the arm of supporting tension pulley block increases.In addition, will guarantee make the derailing part return the guiding function with guide pulley ingear state.And first extendible portion width in axial direction diminishes.

The transmission system of fifth aspect present invention also comprises following structure except comprising the structure identical with the transmission system of second aspect present invention.Arm comprises the first arm partial sum second arm portion.The first arm part in axial direction is arranged in a side of the orbit plane of corresponding guide pulley and tension pulley block.Second arm portion in axial direction is arranged in the opposite side of the orbit plane of corresponding guide pulley and tension pulley block.The first arm partly provides first extendible portion.Second arm portion provides spring housing portion, like this, and in axial direction contiguous second arm portion of spring housing portion.Second arm portion in axial direction is arranged between guide pulley and the spring housing portion.Second arm portion outermost edges radially is positioned at such position, promptly compares with the guiding surface (the derailing part can arrive on this guiding surface) of spring housing portion, and it is equal or littler from the distance of the rotation centerline of guide pulley.

In the transmission system of fifth aspect present invention, derailing part is by the guiding of second extendible portion, like this, under the situation of not interfering with second arm portion, the smooth motion on guiding surface of derailing part, and can return and guide pulley ingear state.

The transmission system of sixth aspect present invention also comprises following structure except comprising the structure identical with the transmission system of fifth aspect present invention.The width that first extendible portion width is in axial direction occupied by two speed-changing chains no better than, these two speed-changing chains are in axial direction adjacent one another are.Second extendible portion width in axial direction is greater than first extendible portion width in axial direction.

In the transmission system of sixth aspect present invention, make the derailing part return the guiding function with guide pulley ingear state by using first extendible portion and second extension to assign to guarantee.In addition, first extendible portion width in axial direction becomes littler.And even when the width of derailing part motion in axial direction is big, second extendible portion makes also that the derailing part is reliable and arrives on second extendible portion, therefore makes the derailing part return and guide pulley ingear state.

The transmission system of seventh aspect present invention relates to the transmission system with following structure.Transmission system comprises: a plurality of speed-changing chains, and these speed-changing chains are in axial direction arranged; And mapping device, be used for making chain to be transformed into another from a sprocket wheel at a plurality of speed-changing chains.Mapping device comprises arm, and this arm is used for rotatably mounted tension pulley block, and this tension pulley block is used for applying tensile force to chain.In transmission system, variable speed operation makes arm in axial direction move.For this arm, provide engagement on its part and recover leader near the tension pulley block part of introducing chain, be used for making the chain derailing part of the orbit plane that broken away from tension pulley block to mesh with tension pulley block.Engagement recovers leader makes whole derailing part radially be positioned at the swing-around trajectory outside of the outermost side of tension pulley block, and the part of guiding derailing simultaneously, so that towards orbit plane motion after make by the tensile force on the chain that in the derailing part derailing part meshes with tension pulley block.

Even variable speed operation makes tension pulley block in axial direction move and makes that therefore chain breaks away from the orbit plane of chain when speed-changing chain stops or being in equivalent situation, this transmission system also makes engagement recover the derailing part of leader guiding chain, thereby makes the derailing of chain partly return and tension pulley block ingear state.This prevents that the derailing part is stuck between tension pulley block and the arm.This can make chain operation.

The transmission system of eighth aspect present invention also comprises following structure except comprising the structure identical with the transmission system of seventh aspect present invention.Mapping device comprises: guide pulley is used for guiding the chain that will hang on the work sprocket wheel of selecting from a plurality of speed-changing chains; And retainer, the rotatably mounted guide pulley of this retainer, and this retainer can in axial direction move with arm.Arm comprises a pair of arm portion, and one of them arm portion is arranged in tension pulley block and the guide pulley side along their axial direction, and another arm portion wherein is arranged in tension pulley block and the guide pulley opposite side along their axial direction.Form side directed part of tension pulley block and supporting part on each arm portion, the portion of chain that the side directed part of this tension pulley block is used to prevent to hang on the tension pulley block breaks away from pulley, and this supporting part is supported by retainer.In axial direction in axial direction the interval between the tension pulley block side guide is divided is wideer at the ratio of the interval between two supporting parts.

This transmission system can increase the bending rigidity (bending rigidity) of each supporting part, this supporting part be on it by the mapping device effect be used to make that part of the power that arm in axial direction moves.In addition, because the axial direction between the tension pulley block side guide is divided forms narrowlyer at interval in arm, so the side directed part of tension pulley block can be arranged to more close tension pulley block.This can make the derailing that recovers the leader guiding by engagement partly be back to the state with the tension pulley block positive engagement.

The transmission system of ninth aspect present invention also comprises following structure except comprising the structure identical with the transmission system of eighth aspect present invention.When the plane, center was defined as the line of centre of gration of the line that comprises the centre of gration of representing tension pulley block and expression guide pulley, forming scope that engagement recovers leader along circumferential direction was to make the direction of rotating forward along the tension pulley block angle from the rotation centerline of tension pulley block to centre plane equal rotation centerline along the contrarotation direction of tension pulley block from tension pulley block to the scope of the angle of centre plane when seeing from the side.

This transmission system can fully guarantee along centre plane, form the scope that engagement recovers leader along circumferential direction.This makes the derailing part be easy to return and tension pulley block ingear state.In addition, engagement recover in the leader, the derailing part is executed power-assisted point and can be designed to close centre plane when derailing part and engagement recover leader and contact.Therefore, this power can reduce the moment that is applied on each arm portion.This makes each arm portion need not be made for bigger for the torsional rigid that increases them or therefore weight is heavier.

The transmission system of tenth aspect present invention also comprises following structure except comprising the structure identical with the transmission system of seventh aspect present invention.Arm comprises a pair of arm portion, and this is arranged in the both sides of tension pulley block to arm portion, and engagement recovers leader and is formed at this respectively in the arm portion.Each engagement recovers leader guide plane, and the derailing part contacts with this guide plane, and this guide plane in axial direction with along the direction vertical with orbit plane extends.In axial direction the guide plane end position of close tension pulley block basically with the inner periphery position consistency of tension pulley block ingear chain or align.

This transmission system makes the derailing part be easy to move on guide plane.This makes and begins derailing, the direction that this position rotates forward along tension pulley block in the position of engagement recovery leader.This has alleviated the chain that causes owing to tension pulley block motion in axial direction and has reversed.This has reduced the resistance of chain when carrying out speed change.

According to first aspect present invention, even owing to rotating, stopping or being in the variable speed operation that carries out under the equivalent state at speed-changing chain backward and make that a part of chain breaks away from the orbit plane of guide pulley, first extendible portion and second extendible portion guiding derailing part, like this, the derailing part meshes with guide pulley once more, thereby makes chain to turn round.Easier the returning and guide pulley ingear state of this feasible derailing part.Therefore, also can carry out variable speed operation even when speed-changing chain does not rotate forward, (comprise the situation that speed-changing chain rotates backward).Therefore, can carry out speed change according to variable speed operation.

According to a second aspect of the invention, except the effect of the invention described above first aspect, also do not need to be used to provide the special-purpose member of first extendible portion and second extendible portion.Therefore, reduce to provide the part count of the transmission system that meshes recovery device, also reduced the cost of transmission system.

According to a third aspect of the invention we, except the effect of the invention described above first or second aspect, also disappear except when guide pulley when motion interference between extendible portion and each speed-changing chain.Therefore guarantee to carry out the reliability of variable speed operation.In addition, guide pulley and each speed-changing chain are arranged to close to each other.This can make the transmission system miniaturization.And, improved the reliability that carries out variable speed operation.In addition, this can smoothly carry out speed change.

According to fourth aspect present invention, any one the effect except the invention described above second or the third aspect also increases the rigidity of arm by using first extension to assign to.In addition, first extendible portion miniaturization in axial direction.And speed-changing chain group and guide pulley are arranged in axial direction closer proximity to each other. therefore, transmission system is miniaturization in axial direction.

According to fifth aspect present invention, except the effect of the invention described above second aspect, the derailing part is by the second extendible portion smooth guide, and like this, the derailing part is returned and guide pulley ingear state.Therefore, improve the derailing part and returned rapidity and reliability with guide pulley ingear state.In addition, improved the reliability that carries out speed change.

According to sixth aspect present invention,, also make extendible portion miniaturization in axial direction except the effect of the invention described above the 5th aspect.Chain wheel set and guide pulley are arranged in axial direction closer proximity to each other.Therefore, transmission system miniaturization in axial direction.And transmission system is miniaturization in axial direction.In addition, improved the reliability that the part of derailing is returned engagement by second extendible portion.In addition, improved the reliability that carries out speed change.

According to seventh aspect present invention, even when making a part of chain break away from the orbit plane of tension pulley block owing to when speed-changing chain stops or being in equivalent state, carrying out variable speed operation, engagement recovers leader and also guides the derailing part, like this, the derailing part meshes once more with tension pulley block, thereby can make chain operation.This is easy to make the derailing part to return and tension pulley block ingear state.Therefore, stop and working as and to carry out variable speed operation when speed-changing chain does not rotate forward when speed-changing chain.Therefore, can carry out speed change according to variable speed operation.

According to eighth aspect present invention, except the effect of the invention described above the 7th aspect, also increased the rigidity of supporting part, power is applied to this supporting part by the mapping device that is used to arm is in axial direction moved.It is lighter that this makes that supporting part can be made for weight.In addition, derailing part can be back to the state with the tension pulley block positive engagement, returns fiduciary level with tension pulley block ingear state thereby improve the derailing part.

According to ninth aspect present invention,, can also fully guarantee to form the scope that engagement recovers leader along circumferential direction except the effect of the invention described above eight aspect.This has improved the derailing part and has returned fiduciary level with tension pulley block ingear state.The derailing partial action can reduce the moment that is applied on each arm portion in the power that engagement recovers on the leader.It is lighter that this can make arm portion be made for weight.

According to tenth aspect present invention, except the effect of the invention described above the 9th aspect, the chain that has also discharged the generation because tension pulley block in axial direction moves reverses.This can more easily carry out variable speed operation.

The embodiment of the invention is below with reference to the accompanying drawings introduced the mode of the present invention of implementing.By below in conjunction with the detailed description of accompanying drawing, will know above-mentioned purpose of the present invention, other purpose, feature and advantage to the embodiment of the invention.

Description of drawings

Fig. 1 is the left side plan view of bicycle that comprises the transmission system of the embodiment of the invention.

Fig. 2 be the gear case of transmission system of Fig. 1 when the cutaway view of the parts of the enlarged diagram when the direction of the arrow II of Fig. 4 is seen and Fig. 4, the figure shows the situation when second housing parts of the transmission system of Fig. 1 is removed.In addition, solid line represents to be positioned at the arm of fast shift position.Long long and two-short dash line represents to be positioned at the arm of slow shift position.

Fig. 3 be the gear case of transmission system of Fig. 1 along the cutaway view of the line III-III of Fig. 2, represented the cutaway view of the parts of derailer.In addition, solid line represents to be positioned at the arm of fast shift position.Long long and two-short dash line represents to be positioned at the arm of slow shift position.

Fig. 4 is that the gear case of transmission system of Fig. 1 is along the cutaway view of the line IV-IV of Fig. 2.For the parts of derailer, Fig. 4 is the cutaway view along the IVa line of Fig. 2.In addition, solid line represents to be positioned at the arm of fast shift position.Long long and two-short dash line represents to be positioned at the arm of slow shift position.

Fig. 5 is that the gear case of transmission system of Fig. 1 is along the cutaway view of the line V-V of Fig. 2.

Fig. 6 is the lateral plan of main portion when the arrow VI direction in Fig. 4 is seen of housing of the transmission system of Fig. 1.

Fig. 7 is the lateral plan of main portion when the arrow VII direction in Fig. 4 is seen of housing of the transmission system of Fig. 1.

Fig. 8 is the cutaway view along the line VIII-VIII among Fig. 6.

Fig. 9 is the enlarged drawing of the main portion of Fig. 4.In addition, solid line represents to be positioned at the arm of fast shift position.Long long and two-short dash line represents to be positioned at the arm of slow shift position.

Figure 10 (A) is the left side view of arm when seeing along the direction opposite with arrow X among Fig. 9 that is arranged on the derailer of transmission system of Fig. 1.In addition, solid line represents to be positioned at the arm of fast shift position.Long long and two-short dash line represents to be positioned at the arm of slow shift position.

Figure 10 (B) is the right side view of arm when the direction of the arrow X in Fig. 9 is seen that is arranged on the derailer of transmission system of Fig. 1.In addition, solid line represents to be positioned at the arm of fast shift position.Long long and two-short dash line represents to be positioned at the arm of slow shift position.

Figure 11 is retainer and the scheme drawing of arm when the direction of the arrow XI in Figure 10 (A) is seen that is arranged on the derailer.

Figure 12 is the scheme drawing of arm when the direction of the arrow XII in Figure 10 (A) is seen that is arranged on the derailer.

The specific embodiment

Below with reference to the selected embodiment of the present invention shown in Fig. 1 to 12 introduction.

As shown in Figure 1, bicycle B provide of the present invention shown in the transmission system T of selected embodiment.Bicycle B comprises: cycle frame F; Bent axle 12, this bent axle 12 operationally is installed on the vehicle frame, and has from this bent axle and stretch out a pair of crank arm 12b, and pedal 13 is installed in the far-end of crank arm.Transmission system T comprises: output shaft 15, and after carrying out speed change, this output shaft is driven in rotation by the power that passes to it; And driving system, this driving system comprises the propulsive effort transmission mechanism.

Cycle frame F comprises head tube 1, and this head tube 1 is at the axle of the rotatably mounted front vehicle wheel Wf in its lower end, and this head tube 1 is so that the mode that front fork 6 can turn to supports this front fork 6, and this front fork 6 is equipped with handle at its top.Cycle frame F comprises: a pair of main car frame 2, this is arranged side by side to main car frame 2, and this to main car frame 2 from head tube 1 extension that recedes downwards; Down tube (down-tube) 3, this down tube 3 is from the extension that recedes downwards of the front end of each main car frame 2; And a pair of bottom tube (under-tube) 4, this is arranged side by side to bottom tube, and this makes the rear end of each main frame 2 be connected with the rear end of each down tube 3 to bottom tube.Cycle frame F also comprises Pillar for saddle 5, and this Pillar for saddle 5 stretches out from each main frame 2, and these Pillar for saddle 5 supporting saddles 8.Two main frames 2 and two down tubes 3 are initial parts that form independent of one another, and link together by welding later on.

Should know, in this specification sheets and claim, the position description on top, bottom, front portion, rear portion, left side and right side is from being sitting on the saddle 8 and seeing top, bottom, front portion, rear portion, left side and the right side that corresponds respectively to bicycle B towards the cyclist's in the place ahead transparent view angle.In addition, the meaning of " axial direction " is the direction that the axial rotary centre line L 3 of each speed-changing chain 41-47 is extended, and the meaning of " from sidepiece " is in axial direction.

A pair of swing arm 10 is arranged side by side, and is operatively connected with vehicle frame F.Swing arm 10 it with the vehicle frame F back end opposite partly locate rotatably mounted rear wheel Wr the axle, as shown in the figure.The front end of each swing arm 10 is bearing on the pivot 9 (also seeing Fig. 3) swingably by the axle on the rear end part that is installed in each swing arm 10, and this pivot 9 is arranged on the rear portion 2a separately of two main frames 2 publicly.Two swing arms 10 are connected with two main frames 2 respectively by rear suspensions 11.Therefore, two swing arms 10 can swing up and down around pivot 9 with the rear wheel Wr that installs.

The main shaft 12a of transmission system T and bent axle 12 and output shaft (both is by the rotatable supporting of the housing of transmission system) are disposed in the space that is positioned at the bottom under the cycle frame, and this space is formed between the rear portion 2a separately of these two main car frames 2 and two bottom tubes 4.In addition, the propulsive effort transmission device is arranged in the right side under the cycle frame.

Except Fig. 1, also as shown in Figure 2, transmission system T comprises betal can or the housing 20 that is made of first housing parts 21 and second housing parts 22, this first housing parts 21 and second housing parts 22 are arranged side by side, and they link together by bolt B 1 (see figure 5) in two boss 21a and 22a, and these two boss 21a and 22a are formed in its adjacent peripheral part.In addition, housing 20 be fixed on each main frame 2 by bolt B 2 (Fig. 1) and each bottom tube 4 on, this bolt B 2 is respectively charged in a pair of mounting portion (Fig. 2 has represented the mounting portion 21b of this first housing parts 21) in the peripheral part that is formed at housing parts 21 and 22. first and second housing parts 21 and 22 that formed by panel material any one by grinding, casting or in suppressing made respectively.

Except Fig. 2, also as shown in Figure 3, bent axle 12 as the main shaft 12a. that is arranged to pass housing 20 bottoms along left and right directions as mentioned above, a pair of crank arm 12b respectively with main shaft 12a, from housing 20, stretch out about hold and be connected.Bent axle 12 can be rotated to support in first housing parts 21 and second housing parts 22 by pair of bearings 14 respectively.In addition, pedal 13 (seeing Figure 13) is rotatably installed on the far-end of each crank arm 12b.

Output shaft 15 be arranged in from main shaft 12a oblique before and the position that makes progress, like this, the rotation centerline L2 of output shaft 15 and the center of oscillation line of each swing arm 10 are parallel to each other, and the center of oscillation line of the rotation centerline L2 of output shaft 15 and each swing arm 10 is simultaneously parallel with the rotation centerline L1 of bent axle 12.In addition, the center of oscillation line of the rotation centerline L2 of output shaft 15 and each swing arm 10 is in the swing-around trajectory of crank arm 12b.Pivot 9 is arranged in the position above the main shaft 12a in fact just, like this, the rotation centerline L2 of output shaft 15 and the center of oscillation line of each swing arm 10 are parallel to each other, the rotation centerline L2 of output shaft 15 is simultaneously parallel with the rotation centerline L1 of bent axle 12 with the center of oscillation line of each swing arm 10, and the center of oscillation line of the rotation centerline L2 of output shaft 15 and each swing arm 10 is in the swing-around trajectory of crank arm 12b.Be fixed in pivot 9 on the main car frame 2 and pass the through hole of each the boss 21c that is formed in first and second housing parts 21 and 22 and 22c and insert, and support first and second housing parts 21 and 22.

As shown in Figure 4, the output shaft 15 that is contained in the housing 20 comprises the end 15a that stretches out from second housing parts 22 to the right.The driving output chain gear 17 that is used to export (this driving output chain gear 17 is the driving bodies that are used to rotate output) is connected with this end 15a.Except Fig. 4, also as shown in Figure 1, the chain 19 in the flexible annular transmission loop that is provided for exporting hangs over and drives on the output chain gear 17, also hangs over the driven sprocket 18 that is used to export, and this driven sprocket 18 is the rotation driven members that are used to export.In addition, drive the propulsive effort transmission mechanism that output chain gear 17, chain 19 and driven sprocket 18 are configured for drive rear wheels Wr (this rear wheel Wr is a drive wheel).

Here mainly will further introduce transmission system T and its block construction.

Shown in Fig. 2 to 4, transmission system T comprises: housing 20; Use the M1 of rapid change mechanism of chain; And speed-changing mechanism M2, this speed-changing mechanism M2 is used for making the rapid change mechanism kinematic to suitable shift position according to variable speed operation.The back is parts of M1 of rapid change mechanism and speed-changing mechanism M2 with the derailer of introducing 70, and in the housing 20 of packing into.

The M1 of rapid change mechanism comprises: free-wheel clutch 30; Ball spline 31, this ball spline 31 is slide mechanisms; Drive input sprocket 32; A plurality of speed-changing chains 41 to 47, these speed-changing chains 41 to 47 are driven sprockets; Ring chain C is used for speed change and is used for the transmission propulsive effort; And chain guide element 50.

The main shaft 12a of bent axle 12 is input shafts, and when the cyclist drove bent axle 12 rotations, drive torque was imported by this input shaft.Driving input sprocket 32 is public sprocket wheels.Drive input sprocket 32 and arrange around main shaft 12a, and coaxial with this main shaft 12a.When driving input sprocket 32 was driven, this driving input sprocket 32 passed through free-wheel clutch 30 and is connected with main shaft 12a.Free-wheel clutch 30 comprises three internal clutch parts 30a, three outer clutch parts 30b and three clutch element 30c.Three internal clutch parts 30a form the part of main shaft 12a.Each outer clutch parts 30b has the ratchet of locating in interior week that is formed at it.Each clutch element 30c is arranged between an internal clutch parts 30a and the corresponding outer clutch parts 30b, and comprises the pawl with the corresponding ratchet engagement of outer clutch parts.30 of free-wheel clutchs will pass to along the rotation (wherein bent axle 12 rotates forward) of direction AO and drive input sprocket 32.Hereinafter, reference marker AO represents when bent axle 17 each and sprocket wheel direction of rotation forward during along hand of rotation AO rotation forward.

Three ball splines 31 are formed at and drive between input sprocket 32 and each free-wheel clutch 30.Each ball spline 31 can make driving input sprocket 32, and (rotation centerline L1 extends in the direction along direction A1 with respect to main shaft 12a, equal axial direction) motion, and make driving input sprocket 32 rotate with the outer clutch parts 30b of a corresponding free-wheel clutch 30.Each ball spline 31 comprises inner cylinder 31a, outside cylinder 31b and a plurality of ball 31c.Inner cylinder 31a links into an integrated entity with outer clutch parts 30b by using connecting pin 33, and rotatably mounted by the periphery of main shaft 12a by the bearing 34 between inner cylinder 31a and periphery.In the radial direction outside of inner cylinder 31a, outside cylinder 31b is arranged to inner cylinder 31a coaxial.In addition, outside cylinder 31b links into an integrated entity with driving input sprocket 32.But pack between a pair of holding tank in a plurality of ball 31c lift-over ground.This is arranged between inner cylinder 31a and the outside cylinder 31b holding tank, and is formed at respectively among inner cylinder 31a and the outside cylinder 31b, so that extend abreast with rotation centerline L1.Although introduced a pair of holding tank above, also can provide many to holding tank.In the present embodiment, three pairs of holding tanks are provided.Therefore, outside cylinder 31b and driving input sprocket 32 are integral rotation with inner cylinder 31a, and lift-over 31c is arranged between outside cylinder 31b and the inner cylinder 31a.On the other hand, outside cylinder 31b and driving input sprocket 32 can move along direction A1 with respect to main shaft 12a and inner cylinder 31 (they can not move along direction A1).

Output shaft 15 is by being arranged in pair of bearings 35 between it and the housing 20 and rotatably mounted by this housing 20, and this is kept by housing parts 21 and 22 respectively bearing 35.Chain wheel set 40 comprises a plurality of sprocket wheels, and the external diameter and the number of teeth of these sprocket wheels differ from one another.In this article, external diameter is the circle diameter that the tooth top by sprocket wheel limits.In the present embodiment, chain wheel set 40 comprises 7 speed-changing chains 41 to 47.The chain wheel set of Gou Chenging is connected with output shaft 15 by using spline like this, thereby makes chain wheel set 40 and output shaft 15 be integral rotation, and chain wheel set 40 is coaxial with output shaft 15.Therefore, the public rotation centerline L3 of speed-changing chain 41 to 47 corresponding to the rotation centerline L1 of bent axle 12 rotation centerline L2 parallel, output shaft 15.All speed-changing chains 41 to 47 are all arranged along their public axial direction according to the order from speed-changing chain 41 order that is used for first speed (expression minimum speed) to the speed-changing chain 47 that is used for the 7th speed (expression maximum speed).In the present embodiment, seven speed-changing chains 41 to 47 are arranged with the order from sprocket wheel order with minimum diameter to the sprocket wheel with maximum gauge left.

Chain C hang over drive on the input sprocket 32 and the sprocket wheel of operating (hereafter is " work sprocket wheel ") on, this work sprocket wheel is in the speed-changing chain 41 to 47.State when each Fig. 2 to 4 has represented to select a speed-changing chain 41-47 by using speed-changing mechanism M2 from chain wheel set 40.Therefore, output shaft 15 is by bent axle 12 driven in rotation, and revolution ratio is determined with work sprocket wheel (this work sprocket wheel is connected with driving input sprocket 32 by chain) by driving input sprocket 32.

Shown in Fig. 2 and 5, chain guide element 50 is arranged in and drives between input sprocket 32 and the chain wheel set 40, and the position of the direction that is pulled by the chain C of bent axle 12 drivings of rotating forward on the edge.Chain guide element 50 formations are prevented locking apparatus, are used for preventing that the slack of chain C is stuck between driving input sprocket 32 and the housing 20 when reducing the position generation slack that makes in the direction that spurs chain C on the chain C on the edge owing to the tensile force on the chain.

Chain guide element 50 comprises leader 51 and suppresses part (check part) 53.This leader 51 forms opening 52, and this opening 52 width in axial direction is less times greater than chain wheel set 40 width in axial direction.Suppress chain C part that part 53 prevents to draw from a speed-changing chain 41 to 47 towards the chain track internal motion.Leader 51 guiding chain C enter opening 52 from a speed-changing chain 41 to 47.Leader 51 comprises inner leader 51a, exterior guiding part 51b and sidepiece leader 51c and 51d.Inner leader 51a is arranged in from opening 52 towards chain track in-to-in position.Exterior guiding parts 51b is arranged in the exterior position from opening 52 towards chain track.Sidepiece leader 51c and 51d are arranged in position outside the both sides along the axial direction of opening 52.In addition, exterior guiding part 51b comprises 51b1 of first and roller 51b2.The 51b1 of first forms the opening 52 that cooperates with inner leader 51a and sidepiece leader 51c, 51d.Roller 51b2 is a second portion, and its relative 51b1 of first is arranged to facing to chain wheel set 40, and it is with chain C guide openings 52.And when seeing inhibition part 53 from the side, this inhibition part 53 is arranged in the position that makes that it and each speed-changing chain 41 to 47 overlap.Inhibition part 53 leader 51a is internally extended towards each speed-changing chain 41 to 47.The tooth group of each speed-changing chain 41 to 47 is passed through groove 53b respectively.Groove 53b has their end parts 53a separately, and the number of end sections 53a equals the number of speed-changing chain 41 to 47.

Inner leader 51a, the 51b1 of first, inhibition part 53 and right side leader 51c constitute first parts of being made by synthetic resin, and these first parts are single parts.Right side leader 51d comprises second parts of being made by synthetic resin.In addition, first and second parts are connected with first housing parts 21 by pair of bolts B3.This is fixed on chain guide element 50 on the housing 20.On the other hand, roller 51b2 is rotatably mounted by bolster 54, and the left side of bolster 54 is supported by the sidepiece leader 51c and first housing parts 21, and the right side of bolster 54 is supported by the sidepiece leader 51d and second housing parts 22.

For example, when making that owing to road bump bicycle B is forced to carry out up-and-down movement at short notice, the part of chain C may teeter along the direction of pulling chain C, and perhaps the part of chain C may be waved with respect to the chain track inside and outside.But, even when on chain C, producing such waving, the chain guide element of Gou Chenging makes chain C contact with exterior guiding part 51b with inner leader 51a through opening 52 time in the above described manner, thereby suppresses the rocking tendency of chain. therefore will prevent that chain from waving. and this makes that bicycle B can smoothness run.

In addition, chain C may move like this, and promptly the tensile force on the chain reduces to make on chain C at the position generation slack along the direction that spurs chain C.For example, bicycle B can carry out inertia and travel forward, and the state that bent axle 12 is in halted state or reverses.At this moment, moment passes to chain wheel set 40 from rear wheel Wr by aforementioned propulsive effort transmission mechanism and aforementioned output shaft 15.This moment drives input sprocket 32 along hand of rotation A0 rotation forward by chain C.At this moment, the tensile force on the chain reduces and will produce the chain slack in the position along the direction that spurs chain C.Particularly, after the bent axle of rotation stops suddenly forward or when the feasible bent axle that has rotated forward rotated in opposite direction, bicycle can continue ahead running.At this moment, it is lax especially that the part of chain C may become, and like this, the part chain will produce before driving input sprocket 32 just and tangle.The entanglement part of chain may be stuck in and drive between input sprocket 32 and the housing 20.

But, even when a part of chain C becomes lax in the position along the direction that spurs chain, chain guide element 50 reduces relaxing among the chain C.This is because chain guide element 50 makes chain C contact with inner leader 51a or exterior guiding part 51b, thereby is suppressed at the slack among the chain C.

And, when a part of chain relaxes especially in the position along the direction that spurs chain, suppress the slack of chain by the inhibition part 53 of chain guide element 50.This prevents that the slack of chain is stuck in the speed-changing chain 41 to 47.In addition, the slack of chain is along suppressing part 53 guiding leaders 51.Therefore, the slack of chain constitutes stagnates portion C 2, this makes the slack of chain temporarily be stuck in from driving input sprocket 32 and opening 52 position towards chain wheel set 40, and this position is (state when Fig. 6 has represented that the part of chain C is stagnated) between leader 51 and chain wheel set 40.Like this, chain guide element 50 prevents that the slack (this slack results from along the position of pulling chain C direction) of chain C is stuck between driving input sprocket 32 and the housing 20.And inner leader 51a and roller 51b2 also guide chain C along the mode of pulled straight and process opening 52 continuously so that stagnate portion C 2.Like this, chain guide element 50 still is used to align and stagnates the chain aligning apparatus of portion C 2.

Suppose that the shift position that is provided by chain wheel set 40 is divided equally into low speed and high speed position. in the chain C part of position along the direction of pulling chain, inner leader 51a partly contacts with the chain C of (this sprocket wheel is the work sprocket wheel that is in high speed position) in hanging over speed-changing chain 44 to 47.Roller 51b2 partly contacts with the chain C of (this sprocket wheel is the work sprocket wheel that is in low-speed position) in hanging over speed-changing chain 41 to 43.

To shown in 9, sprocket wheel 41 and 47 is to be arranged in along the outermost end of the axial direction of chain wheel set 40 sprocket wheel as Fig. 2,4 and 6, simultaneously along the most close housing 20 of the axial direction of chain wheel set 40.In two speed-changing chains 41 and 47, the in axial direction more close housing 20 of speed-changing chain 41.For speed-changing chain 41, transmission system T utilizes the part of housing 20 and projection 56 is provided, and this projection 56 is to be used for making chain C prevent when being converted on the speed-changing chain 41 that chain C from axial direction surpassing the inhibition part of speed-changing chain 41 motions when the derailer 70 that in axial direction moves.

Specifically, when chain C when a sprocket wheel is converted to another sprocket wheel the chain wheel set 40, projection 56 prevents that chain C from axial direction surpassing speed-changing chain 41 motions, in order to avoid too close first housing 21 of chain C.This projection 56 is integral with first housing 21 as the part of housing 20, and it is when be in the position that makes projection 56 and portion C 1 (chain C hangs on this portion C 1) overlapping of speed-changing chain 41 when sidepiece is seen.For projection 56, in axial direction Ding Wei top section 56c has top surface 56d, this top surface is to be used to suppress the inhibition surface that chain C in axial direction moves. therefore, when chain C will in axial direction surpass speed-changing chain 41 motions, chain C contacted with this top surface 56d.This prevents that chain C breaks away from speed-changing chain 41.

Projection 56 comprises 56a of first and second portion 56b.When sidepiece is seen, the portion C 1 of 56a of first and speed-changing chain 41 (chain C hangs on this portion C 1) overlaps.Second portion 56b extends among the 56a of first, and along hand of rotation A0 is longer than the 56a of first extension close speed-changing chain 41, that make the part place that chain C draws forward.Second portion 56b from the 56a of first towards chain guide element 50 inhibition part 53 extend. when bent axle 12 does not rotate forward or under equivalent situation, chain guide element 50 causes the stagnation portion C 2 on chain C.When making guide pulley 72 in axial direction towards speed-changing chain 41 motions at the variable speed operation under this state, second portion 56b prevents to stagnate portion C 2 and in axial direction surpasses speed-changing chain 41 more close first housings 21.

In addition, strengthen the rib and first housing 21 and be integrally molded, and be arranged on this first housing 21.Strengthening rib stretches out from the radial direction of projection 56 upper edge speed-changing chains 41.Strengthen rib and comprise a plurality of internal rib 57 and a plurality of external rib 58.Internal rib 57 radially stretches out from projection 56, and arranges at interval along circumferential direction.External rib 58 is arranged on the projection 56 at interval along circumferential direction.Internal rib 57 is arranged to protrude along the axial direction identical with projection 56.Top surface 57a each internal rib 57, in axial direction almost is positioned at the position identical with top surface 56d.When sidepiece is seen, each external rib 58 is arranged in the position with corresponding internal rib 58 equal angular, and rotation centerline L3 is defined as the center.Therefore, the number of external rib 58 is identical with the number of internal rib 57.

As shown in Figures 1 to 3, speed-changing mechanism M2 provides speed changing operating mechanism 60 and derailer 70.Derailer 70 is to be used for making chain C be converted to the trnasistion mechanism of another sprocket wheel of chain wheel set 40 from a sprocket wheel in response to the variable speed operation of speed changing operating mechanism 60.Chain C hangs over and drives on input sprocket 32, work sprocket wheel, guide pulley 72 and the tension pulley block 82.Guide pulley 72 and tension pulley block 82 are arranged in the slack of the chain C that is driven by rotary crankshaft forward 12.

Speed changing operating mechanism 60 is connected with derailer 70 in the housing 20.Speed changing operating mechanism 60 provides variable-speed operation parts 61 and operation cable 62.Variable-speed operation parts 61 comprises the variable speed operation bar that is waited operation by the cyclist.Operation cable 62 is the operating effort transferring elements that are used to be operatively connected variable-speed operation parts 61 and derailer 70, is used for the operation of variable-speed operation parts 61 is passed to derailer 70.Operation cable 62 comprises outside cable 62a and inner cable 62b.Outside cable 62a is tubular, and is kept by cycle frame F. inner cable 62b inserts this cable 62a inside, outside.The end parts of inner cable 62b is connected with variable-speed operation parts 61, and the other end of inner cable is connected with derailer 70.

Shown in Fig. 2 to 5 and 9, derailer 70 is arranged in above the main shaft 12a of bent axle 12, and provides base part 71, guide pulley 72, retainer H, parallelogram linkage 73 and tensioner 74.Base part 71 is fixed on two housing parts 21 and 22 and by these two housing parts 21 and 22 and keeps, and provides the retaining part that is used for outside cable 62a 71a.The shape of base part 71 is similar to cylinder.Guide pulley 72 is the guide members that are used to guide chain C, and like this, when chain C will be when speed-changing chain 41 moves between 47, chain C hangs on the work sprocket wheel.The rotatably mounted guide pulley 72 of retainer H.Parallelogram linkage 72 links together base part 71 and retainer H, and pair of links 73a and 73b are arranged.This is to be used for making the operating mechanism that retainer H and guide pulley 72 are moved along axial direction and the radial direction of rotation centerline L3 in response to the variable speed operation that is undertaken by speed changing operating mechanism 60 to connecting rod 73a and 73b.Tensioner 74 provides tensile force to chain C.

Retainer H comprises first retaining part 76 and second retaining part 77 and supporting part 78.First retaining part 76 and second retaining part 77 are arranged in the left part and right side part of guide pulley 72, and these two parts are guide pulley both sides in axial direction.First retaining part 76 and second retaining part 77 interconnect by a pair of rivet 75a and 75b.The rotation centerline L4 of guide pulley 72 self is parallel with rotation centerline L3.Supporting part 78 rotatably mounted guide pulley 72.Supporting part 78 comprises collar 78a and bearing 78b.Collar 78a is assemblied in the outside of rivet 75a, and this rivet 75a is the parts that are used to connect first retaining part 76 and second retaining part 77.Collar 78a is controlled at the axially spaced-apart between first retaining part 76 and second retaining part 77.Bearing 78b is assemblied in the outside of collar 78a, and supporting guide pulley 72.The interior section 78b1 of bearing 78b is supported swingably by collar 78a.This interior section 78b1 is controlled at the axially spaced-apart between the first arm part 100 and second arm portion 120 (back will be introduced).Interior section 78b1 and two arm portions 100 and 120 are integral swing, and these two arm portions 100 are connected with interior section 78b1 by pushing insertion with 120.

The first retainer part 76 is arranged in the left side of guide pulley 72, and comprises plate shape parts.Second retaining part 77 provides connecting bridge 79 and spring housing portion 80.Connecting bridge 79 is arranged to along guide pulley 72 radially outward.This is connected with connecting bridge 79 by swinging fabricated section with 73b connecting rod 73a.Spring housing portion 80 is arranged in the right side of guide pulley 72, and holds tensioning spring 83.In addition, two of parallelogram linkage 73 connecting rod 73a and 73b are installed on the base part 71 by a pair of bolster 81 that is arranged on the base part 71.Inner cable 62b is kept by the connecting bridge 73b1 of connecting rod 73b, and meshes with this connecting bridge 73b1.When by inner cable 62b operation, two connecting rod 73a and 73b swing around a pair of center of oscillation lines of being determined by bolster 81 respectively, and along tooth top circle group (this tooth top circle group comprises the circle that the tooth top by speed-changing chain 41 to 47 draws) guide pulley 72.

In addition as shown in figure 11, spring housing portion 80 has peripheral wall 80a, and this peripheral wall 80a constitutes and the second relative extendible portion of first extendible portion 106 (back will be introduced).When in axial direction seeing, peripheral wall 80a is arranged in the right side of the orbit plane P1 of guide pulley 72.Specifically, spring housing portion 80 is arranged in the position of close second arm portion 120 (back will be introduced) in axial direction.Spring housing portion 80 has the peripheral wall 80a that is in second arm portion, 120 right positions.Peripheral wall 80a is along the direction of deorbit plane P 1 and the right side that extends to orbit plane P1 along the direction parallel with axial direction.Peripheral wall 80a has the outer peripheral surface portion that is formed by cylindrical surface, as guiding surface 80b.In addition, compare with chain C width W 4 in axial direction, the axially spaced-apart between second arm portion 120 and spring housing portion 80 is very little.Shown in the back, in axial direction the interval between second arm portion 120 and spring housing portion 80 be arranged to enough little, to such an extent as to can overslaugh chain C when the derailing of chain C is partly returned with guide pulley 72 ingear states motion (at this moment its an end surfaces 80b on slide) at peripheral wall 80.

Here, the orbit plane P1 of guide pulley 72 is defined as the plane of a plurality of tooth 72a (seeing Fig. 9 and 10) that cross guide pulley 72, these teeth and chain C engagement.Orbit plane P1 and rotation centerline L4 meet at right angles.Figure 11 has represented to cross the orbit plane of tooth 72a.

Shown in Fig. 2 and 4, tensioner 74 provides tension pulley block 82, arm R and tensioning spring 83.Tension pulley block 82 applies tensile force by push chain C between driving input sprocket 32 and guide pulley 72 to chain C.Arm R in axial direction is arranged between the first retainer part 76 and the second retainer part 77, and links into an integrated entity with the supporting part 78 of retainer H by inserting by force, and rotatably mounted tension pulley block 82.In addition, retainer H and arm R constitute the pulley bearing parts in the derailer 70.

Arm R comprises double-type each other the first arm part 100 and second arm portion 120 and supporting part 84.The first arm part 100 and second arm portion 120 are arranged in the position on tension pulley block 82 left sides and right side, and this position is in the both sides of the axial direction of tension pulley block 82.Simultaneously, the first arm part 100 and second arm portion 120 in axial direction are arranged between first retaining part 76 and second retaining part 77.Supporting part 84 rotatably mounted tension pulley blocks 82.

The first arm part 100 provides the side directed part 101 of guide pulley and side directed part 102, the second arm portions 120 of tension pulley block provide side directed part 121 of guide pulley and the side directed part 122 of tension pulley block.The side directed part 101 of guide pulley and 121 prevents that chain C breaks away from guide pulley 72, and supporting is by the part of supporting part 78 supportings.Side directed part 102 of tension pulley block and 122 supporting supporting parts 84, and prevent that chain C breaks away from tension pulley block 82.And supporting part 84 comprises rivet 84a and bearing 84b.Rivet 84a is the parts that connect the first arm part 100 and second arm portion 120.Bearing 84b is assemblied in the outside of rivet 84a, and supporting tension pulley block 82.

In axial direction be arranged to greater than the interval W2 between two side directed parts 102 of tension pulley block and 122 (this interval W2 is controlled by the interior section 84b1 of bearing 84b) in axial direction at the interval W1 between two side directed parts 101 of guide pulley and 121 (this interval W1 is by the interior section 78b1 of bearing 78b control).In addition, the axial width of guide pulley 72 is greater than the axial width of tension pulley block 82.

Tensioning spring 83 comprises spring 83a and 83b, and each spring is made by two reset coil springs that different-diameter is arranged respectively.Two spring 83a and 83b are arranged in the spring housing portion 80 with one heart.The end of each spring 83a and 83b and spring housing portion 80 mesh and are kept by this spring housing portion 80.The other end of each spring 83a and 83b keeps (see figure 10) with the mate 120a of second arm portion 120 and 120b engagement and by them respectively.For they spring forces separately, spring 83a and 83b provide the power of cw around the rotation centerline L4 of Fig. 2 to arm R and tension pulley block 82, thereby tension pulley block 82 is pressed against on the chain C.Then, tension pulley block 82 is swung with arm R.Therefore, the tensile force of chain C is regulated by the spring force of each spring 83a and 83b.

As shown in Figures 9 and 10, the first arm part 100 is plate shape parts, and the side directed part 101 of guide pulley, the side directed part 102 of tension pulley block and connecting bridge 103 are integrally molded therein.The side directed part 101 of guide pulley forms similar fan-shaped, and is formed at along in the certain limit of the circumferential direction of guide pulley 72, and this scope comprises guide pulley 72 portion C 3 that tangle chain C.The side directed part 102 of tension pulley block forms similar fan-shaped, and is formed at along in the certain limit of the circumferential direction of tension pulley block 82, and this scope comprises tension pulley block 82 portion C 4 that tangle chain C.Connecting bridge 103 connects two leaders 101 and 102.

The side directed part 101 of guide pulley comprises larger-diameter neighboring part 104 and than the neighboring part 105 of minor diameter.Larger-diameter neighboring part 104 is arranged in and makes near guide pulley 72 positions that chain C introduces.Divide 105 to extend in the larger-diameter neighboring part 104 than the minor diameter peripheral edge portion, and be arranged in and make near guide pulley 72 positions that chain C draws.When sidepiece is seen, larger-diameter neighboring part 104 is arranged in the position that makes that larger-diameter neighboring part 104 and guide pulley 72 portion C 3 that tangle chain C overlap.Be positioned at larger-diameter neighboring part 104 and tangle the radially inner side of guide pulley 72 portion C 3 of chain C than the neighboring part 105 of minor diameter, and be positioned at rotation centerline L4 near.In addition, than the neighboring part 105 of minor diameter end sections 105a is arranged, this end sections 105a is in the position (back will be introduced) of crossing centre plane P3 along circumferential direction.And connecting bridge 103 constitutes derailing and prevents part, is used to prevent that chain C from leaving guide pulley 72 left near the guide pulley position that chain C introduces making.

As shown in figure 11, two neighboring parts 104 provide first extendible portion 106 with 105 directions along deorbit plane P 1 jointly with the edge direction parallel with axial direction, and this first extendible portion 106 extends along the axial directions on the left of the orbit plane P1 of guide pulley 72.First extendible portion 106 that in axial direction is arranged in the orbit plane P1 left side of guide pulley 72 extends in two neighboring parts 104 and 105.In addition, first extendible portion 106 also extends to the end 103a of connecting bridge 103 continuously near guide pulley 72 parts that make chain C introduce, and like this, this continuous extendible portion arrives in axial direction the position that overlaps with tension pulley block 82.And extendible portion 106 is molded in two neighboring parts 104 and 105 to form similar arc, and moldedly in the end sections 103a of connecting bridge 103 forms line-like shape.And extendible portion 106 is molded as and makes side directed part 101 of guide pulley and connecting bridge 103 along folding (fold) abreast with axial direction.Extendible portion 106 forms one with side directed part 101 of guide pulley and connecting bridge 103, also forms one with the first arm part 100.

The guiding surface 107 that is made of the outer surface of extendible portion 106 extends along the direction of deorbit plane P 1, perhaps extends and extends along almost parallel with axial direction direction towards orbit plane P1 left side.Guiding surface 107 smoothly stretches in surperficial 104b and the 105b, and this surface 104b and 105b face toward guide pulley 72 in two neighboring parts 104 and 105.In addition, extendible portion 106 (and guide plane 107) width W 3 in axial direction chain C width W 4 in axial direction no better than.The axial width (Fig. 9 has represented two speed-changing chains 45 and 46 width that occupy, as the representative instance of width W 5) that width W 3 is occupied by two speed-changing chains 41 to 47 (these two speed-changing chains are adjacent to each other along the axial direction of chain wheel set 40) no better than.And the peripheral wall 80a of spring housing portion 80 (and guiding surface 80b) width W 6 in axial direction is arranged to the width W 3 greater than extendible portion 106 (and guide plane 107).

In addition, dividing extendible portion 106 and guiding surface 107 in 105 to be positioned to than extendible portion 106 in larger-diameter neighboring part 104 and guiding surface 107 more close rotation centerline L4 than the minor diameter peripheral edge portion, when when sidepiece is seen, this larger-diameter neighboring part 104 is in the position that makes that it and the guide pulley that tangles chain C partly overlap.Dividing extendible portion 106 and guiding surface 107 in 105 also to be positioned to more close rotation centerline L4 than the swing-around trajectory 72c in the most peripheral end of guide pulley 72 than the minor diameter peripheral edge portion.And, when than the neighboring part 105 of minor diameter near the position of larger-diameter neighboring part 104 during, at rotation centerline L4 with dividing one group of extendible portion 106 in 105 than the minor diameter peripheral edge portion and the distance between the guiding surface 107 diminishes continuously near end sections 105a.Therefore, extendible portion 106 and guiding surface 107 are gradually near rotation centerline L4.

Shown in Fig. 4,10 and 12, the first engagement recovery leader 110 and derailing that the side directed part 102 of tension pulley block is included in the tension pulley block 82 part vicinity of introducing chain C prevent part 111.First engagement recovers leader 110 and comprises the neighboring part, and this neighboring part is used to cover the scope that forms the side directed part 102 of tension pulley block along circumferential direction.Derailing prevents that part 111 is arranged in the position of leaving engagement recovery leader 110 along the A0 of hand of rotation forward of tension pulley block 82, and prevents that chain C from leaving tension pulley block 82.

Derailing portion C 12 is the chain C parts of in axial direction derailing from the orbit plane P2 of tension pulley block 82, to introduce below the engagement of derailing portion C 12. first recover leaders 110 by so that the neighboring part of the side directed part 102 of tension pulley block in a certain direction folding first engagement of bevelled mode recover leader 110 and form, this direction makes neighboring part when the side directed part 102 of tension pulley block along the radial direction of tension pulley block 82 when outside, and the neighboring part of the side directed part 102 of tension pulley block is deorbit plane P left 2 in axial direction.It is the extendible portions that extend along the part axial direction left from the side directed part 102 of tension pulley block that first engagement recovers leader 110, and this part is relative with tension pulley block 82.And engagement recovers leader 110 guiding surface 112, and this guiding surface is formed by inclined surface, and this inclined surface is made by outwardly trochoidal surface radially.In other words, engagement recovers leader 110 guiding surface 112, and this guiding surface is formed by bevelled inclined surface in a certain direction, and this direction makes inclined surface deorbit plane P left 2 when inclined surface is radially outside.And in axial direction the guiding surface 112 end sections 112a of the most close tension pulley block 82 are positioned at inner side place guiding surface 112, radially.The end sections 112a of guiding surface 112 is positioned at almost with the radial direction inner edge portion of tension pulley block 82 ingear chain C part and divides position of living in identical position.In other words, the end sections 112a of guiding surface 112 is positioned at almost and identical position, inward flange part C4a present position along the radial direction of the portion C 4 of tension pulley block 82 parts that tangle chain C.

Here, the orbit plane P2 of tension pulley block 82 is the planes of crossing a plurality of tooth 82a, these teeth 82a be tension pulley block 82, with chain C ingear part (see figure 10), and this orbit plane P2 is perpendicular to rotation centerline L5 (Figure 12 has represented to cross the orbit plane of tooth 82a).

Engagement recovers the leader 110 width W 7 in axial direction width W 4 of chain C no better than.In addition, the scope that forms the side directed part 102 of tension pulley block is arranged on and makes in the scope that angle θ 1 and angle θ 2 (see figure 10)s almost are equal to each other.When seeing from the side, angle θ 1 is the angle of relative centre plane P3, and this angle is around the hand of rotation A0 measurement forward of rotation centerline L5 edge; And angle θ 2 is angles of relative centre plane P3, and this angle is measured along hand of rotation backward around centre line L 5, and centre plane P3 is defined as the rotation centerline L4 that comprises guide pulley 72 and the rotation centerline L5 of tension pulley block 82.Generally, the side directed part 102 of tension pulley block is arranged on and makes that the angle θ 1 of relative rotation centerline L5 and the summation of angle θ 2 are in the scope at obtuse angle.And derailing prevents part 111 above meshing recovery leader 110 and extending radially outwardly.Surpassing the radially outside position of tension pulley block portion C 4 tangle chain C, derailing prevent part 111 by as the rivet 85 of connecting bridge and with second arm portion 120 in, the derailing of the side directed part 122 of tension pulley block prevents that part 131 is connected.

In Fig. 9,10 and 11, second arm portion 120 is plate shape parts, and wherein, the side directed part 121 of guide pulley, the side directed part 122 of tension pulley block and connecting bridge 123 form one mutually.Guide pulley side part 121 is fan-shaped, and is formed at along in the certain limit of guide pulley 72 circumferential direction, and this scope comprises guide pulley 72 portion C 3 that tangle chain C.Tension pulley block side part 122 is fan-shaped, and is formed at along in the certain limit of tension pulley block 82 circumferential direction, and this scope comprises tension pulley block 82 portion C 4 that tangle chain C.Connecting bridge 123 links together two leaders 121 and 122.

The side directed part 121 of guide pulley comprises neighboring part 134, and this neighboring is arranged in the scope between the part of drawing chain C of partial sum guide pulley 72 of introducing chain C of guide pulley 72.When seeing from the side, as if neighboring part 124 is positioned at and makes that this neighboring part 124 is overlapping with the guide pulley portion C 3 that tangles chain C.For neighboring part 124, inclined surface 125 be formed at above the swing-around trajectory 82c of the outermost peripheral of guide pulley 72, along in the outside position of the radial direction of guide pulley 72.Inclined surface 125 tilts along such direction, and promptly this direction makes that when inclined surface 125 radially stretched out, inclined surface 125 radially extended along deorbit plane P 1 to the right.In addition, inclined surface 125 is formed among the end sections 123a of connecting bridge 123 in the part vicinity of the introducing chain C of guide pulley 72.When viewed from above, as if inclined surface 125 forms and extends to the position that makes that inclined surface 125 overlaps with tension pulley block 82.

And the diameter of neighboring part 124 is greater than the diameter than major diameter neighboring part 104 of the first arm part 100.Outermost edges 124a is the part in the inclined surface 125 of extending to of neighboring part 124, and this part is outside along the guide pulley radial direction.Outermost edges 124 is formed by the damaged surface of the equal diameters of the guiding surface 80b of the peripheral wall 80a of diameter and spring housing portion 80.When radially seeing, outermost edges 124a is positioned at the identical position, guiding surface 80b present position with spring housing portion 80.Therefore, between rotation centerline L4 and the guiding surface 80b equal apart from d2 between rotation centerline L4 and outermost edges 124a apart from d2.Between rotation centerline L4 and guiding surface 107 apart from d1 less than distance d2.And connecting bridge 123 constitutes and prevents that the derailing that chain C breaks away from guide pulley 72 and tension pulley block 82 to the right from preventing part.

Shown in Fig. 4,10,12, the side directed part 122 of tension pulley block forms along side directed part 102 symmetries of the tension pulley block of symmetrical plane and the first arm part 100, and this symmetrical plane is the plane vertical with rotation centerline L5.The side directed part 122 of tension pulley block has second engagement to recover leader 130 and derailing prevents part 131.Second engagement recovers leader 130 and comprises the neighboring part, this peripheral edge portion branch be arranged in tension pulley block 82 introducing chain C part near, so that cover along in the circumferential direction certain limit, the side directed part 122 of tension pulley block is recovered leader 110 with engagement and is formed at jointly in this circumferential direction scope.Derailing prevents that part 131 and derailing from preventing that part 111 is similar.

Derailing portion C 14 is in axial direction from the chain C part of the orbit plane P2 of tension pulley block 82 derailing.Second engagement recovers leader 130 makes derailing portion C 14 mesh with tension pulley block 82 once more.Second engagement recover leader 130 by so that the neighboring part of the side directed part 122 of tension pulley block in a certain direction folding second engagement of bevelled mode recover leader 130 and form, this direction make when the neighboring part of the side directed part 122 of tension pulley block when the radial direction of tension pulley block 82 stretches out, the neighboring part of the side directed part 122 of tension pulley block is deorbit plane P to the right 2 in axial direction.It is the extendible portions that extend along the part axial direction to the right from the side directed part 122 of tension pulley block that second engagement recovers leader 130, and this part is relative with tension pulley block 82.And engagement recovers leader 130 guiding surface 132, and this guiding surface is formed by inclined surface, and this inclined surface is made by outwardly trochoidal surface radially.In other words, engagement recovers leader 130 guiding surface 132, and this guiding surface is formed by bevelled inclined surface in a certain direction, this direction feasible when inclined surface radially stretches out inclined surface deorbit plane P to the right 2.And in axial direction the guiding surface 132 end sections 132a of the most close tension pulley block 82 are positioned at inner side place guiding surface 132, radially.The end sections 132a of guiding surface 132 is positioned at almost and identical position, inward flange part C4a present position along the radial direction of the portion C 4 of the tension pulley block 82 that tangles chain C.

Engagement recovers the leader 130 width W 8 in axial direction width W 4 of chain C no better than.In addition, the circumferential direction scope of the side directed part 102 of formation tension pulley block is identical with the circumferential direction scope that meshes the side directed part 102 of recovery leader 110 formation tension pulley blocks relatively.And derailing prevents part 131 above meshing recovery leader 130 and extending radially outwardly.

Engagement recovers leader 110 and 130 and comprises bevelled leader 110a and 130a respectively, this make engagement recover between the leader 110 and 130 axial direction at interval when this engagement recover leader 110 and 130 respectively the edge forward hand of rotation A0 when derailing prevents part 111 and 131 extensions, diminish.

To be presented in below that speed-changing chain 41 to 47 rotates backward or when stopping (in other words when speed-changing chain 41 to 47 does not rotate forward, for example when bicycle be in backward the state of motion or when bicycle B stops) carry out under the situation of variable speed operation, the peripheral wall 80a of extendible portion 106, spring housing portion 80 and pair of meshing recovered part 110 and 130 guide the function of chain C.

As Fig. 3,4 and 10 to shown in 12, when the operation of speed changing operating mechanism 60 will make chain movement to faster shift position, when speed-changing chain 41 to 47 did not rotate forward simultaneously, the operation of the parallelogram linkage 73 of derailer 70 made guide pulley 72 and tension pulley block 82 move right with retainer H and arm R.Therefore, the portion C that tangles chain C 4 of the portion C that tangles chain C 3 of guide pulley 72 and tension pulley block 82 moves right with guide pulley 72 and tension pulley block 82.On the contrary, the part that tangles chain C of one of them of speed-changing chain 41 to 47 does not move right.In addition, the part that tangles chain C of driving input sprocket 32 does not move to and guide pulley 72 and tension pulley block 82 corresponding positions.Therefore, the portion C that tangles chain C 3 of guide pulley 72 and the portion C that tangles chain C 4 of tension pulley block 82 from a position to left movement, in this position, connecting bridge 103 and derailing prevent that part 111 from hindering the portion C that tangles chain C 4 of the portion C that tangles chain C 3 of guide pulley 72 and tension pulley block 82 to left movement.Therefore, in some cases, the portion C that tangles chain C 3 of guide pulley 72 and the portion C that tangles chain C 4 of tension pulley block 82 may be near connecting bridge 103 and derailing part 111 de-orbit plane P 1 and P2.In other words, the portion C that tangles chain C 4 of the portion C that tangles chain C 3 of guide pulley 72 and tension pulley block 82 may break away from guide pulley 72 and tension pulley block 82.

Here, be start-up portion C11a when chain C begins to break away near connecting bridge 103 and 123 position.Prevent that near derailing the position of part 111 and 131 from being the start-up portion C12a that chain C begins to break away from.Derailing portion C 1 is the chain C part that beginning breaks away from start-up portion C11a place.Derailing portion C 12 is chain C parts that beginning breaks away from start-up portion C12a place.For guide pulley 72, derailing portion C 11 is moved on extendible portion 106 or guiding surface 107, for example shown in the two dash lines of the dash among Figure 11.For tension pulley block 82, derailing portion C 12 is recovered motion on leader 110 or the guiding surface 112 in engagement, for example shown in the two dash lines of the dash among Figure 12.

When derailing portion C 11 was in this state, extendible portion 106 made the part derailing portion C 11 in the guide pulley 72 part vicinity of introducing chain C be positioned to radially outside above the swing-around trajectory 72c of guide pulley 72.In addition, when the cyclist for example drives bent axle 12 along hand of rotation A0 forward, therefore and when speed-changing chain 41 to 47 being rotated forward, extendible portion 106 guiding are the derailing portion C 11 of motion on extendible portion 106, like this, at this moment make derailing portion C 11 on guiding surface 107, slide at the tensile force on the chain C, thereby towards orbit plane P motion, and therefore mesh with guide pulley 72.

When variable speed operation will make that chain C moves to faster shift position, if variable speed operation is skipped several speed-changing chains, perhaps when analogue took place, the work sprocket wheel after variable speed operation and the difference of the external diameter between the work sprocket wheel before the variable speed operation became bigger.Even under these circumstances, in extendible portion 106, help to make reliably derailing portion C 11 to arrive on the extendible portions 106, shown in the dash dash line among Figure 10 than the extendible portion 106 of the neighboring part 105 of minor diameter.Therefore, with when divide at rotation centerline L4 with than the minor diameter peripheral edge portion distance between 105 the extendible portion 106 equal rotation centerline L4 and than between the extendible portion 106 of major diameter neighboring part 104 apart from the time situation compare, extendible portion 106 can make derailing portion C 11 reliable arrival on the extendible portion 106, and can not make derailing portion C 11 break away from extendible portion 106.

On the other hand, engagement recovers leader 110 and 130 to make that whole derailing portion C 12 is positioned to surpass the swing-around trajectory 82c of tension pulley block 82 radially outside.In addition, when the cyclist drives bent axle 12 along hand of rotation AO forward, and therefore make when speed-changing chain 41 to 47 rotates forward, engagement recovers leader 110 and 130 guiding derailing portion C 12, like this, the tensile force that acts on the chain C makes derailing portion C 12 towards orbit plane P2 motion, and therefore meshes with tension pulley block 82.

When the operation of speed changing operating mechanism 60 will make chain movement to slower shift position, when speed-changing chain 41 to 47 did not rotate forward simultaneously, the operation of parallelogram linkage 73 made guide pulley 72 and tension pulley block 82 to left movement.Therefore, the portion C that tangles chain C 4 of the portion C that tangles chain C 3 of guide pulley 72 and tension pulley block 82 with guide pulley 72 and tension pulley block 82 to left movement.On the contrary, one of them a part that tangles chain C of speed-changing chain 41 to 47 is not to left movement.In addition, the part that tangles chain C of driving input sprocket 32 does not move to and guide pulley 72 and tension pulley block 82 corresponding positions.Therefore, the portion C that tangles chain C 3 of guide pulley 72 and the portion C that tangles chain C 4 of tension pulley block 82 move right from a position, in this position, connecting bridge 103 and derailing prevent that part 111 from hindering the portion C that tangles chain C 3 of guide pulley 72 and the portion C that tangles chain C 4 of tension pulley block 82 moves right.Therefore, in some cases, near the portion C that tangles chain C 3 of guide pulley 72 plane P 1 that may connecting bridge 123, de-orbit.In other cases, the portion C that tangles chain C 4 of tension pulley block 82 may be near the derailing plane P 2 that de-orbit the part 131.

At this moment, for guide pulley 72, the derailing portion C 13 outside the derailing part arrives on the peripheral wall 80a or guiding surface 80b of spring housing portion 80, for example shown in the two dash lines of the dash among Figure 11.For tension pulley block 82, derailing portion C 14 arrives engagement and recovers on leader 130 or the guiding surface 132, for example shown in the two dash lines of the dash among Figure 12.

When derailing portion C 13 was in this state, peripheral wall 80a made the part derailing portion C 11 in the guide pulley 72 part vicinity of introducing chain C be positioned to radially outside above the swing-around trajectory 72c of guide pulley 72.Peripheral wall 80a guiding has arrived the derailing portion C 13 on the peripheral wall 80a, like this, owing to the tensile force that cause, on chain C of rotation forward by bent axle 12, the derailing part is slided on guiding surface 80b, towards orbit plane P1 motion, and therefore mesh with guide pulley 72.And, when variable speed operation will make that chain C moves to slower shift position, if variable speed operation is skipped several speed-changing chains, perhaps when analogue took place, the work sprocket wheel after variable speed operation and the difference of the external diameter between the work sprocket wheel before the variable speed operation became bigger.Even under these circumstances, because the width W 6 of peripheral wall 80a greater than the width W 3 of extendible portion 106, therefore helps making reliably derailing portion C 13 to arrive on the peripheral wall 80a.Therefore, this peripheral wall 80a makes derailing portion C 13 to go up and can not make derailing portion C 131 disengaging peripheral wall 80a by more reliable arrival peripheral wall 80a.

On the other hand, engagement recovers leader 130 to make that whole derailing portion C 14 is positioned to surpass the swing-around trajectory 82c of tension pulley block 82 radially outside.In addition, owing to by rotating forward of bent axle 12 tensile force that cause, on chain C, engagement recovers leader 130 guiding derailing portion C 14, and like this, derailing portion C 14 is towards orbit plane P2 motion, and therefore with tension pulley block 82 engagements.

Like this, no matter guide pulley 72 and tension pulley block 82 motions to the left or to the right in axial direction in response to variable speed operation, derailing portion C 11 and C12 recover leader 110 guiding by extendible portion 106 and engagement respectively, like this, derailing portion C 11 and C12 returns respectively and guide pulley 72 and tension pulley block 82 ingear states.Derailing portion C 13 and C14 recover leader 130 guiding by peripheral wall 80a and engagement respectively, and like this, derailing portion C 13 and C14 return and guide pulley 72 and tension pulley block 82 ingear states.Therefore, the extendible portion 106 of spring housing portion 80 and peripheral wall 80a constitute the engagement recovery device, are used for making the derailing portion C 11 and the C13 that derail from the orbit plane P1 of guide pulley 72 to mesh with guide pulley 72.

To introduce function and the effect of the embodiment that constitutes in the above described manner below.

When the cyclist drives bent axle 12 along hand of rotation A0 forward, perhaps when bicycle B ahead running and bent axle 12 are in the state of rotation backward or are in halted state, the operation of variable-speed operation parts 61 makes retainer H, guide pulley 72, arm R and the tension pulley block 82 of derailer 70 occupy the 7th shift position, the 7th shift position is a home position, shown in solid line among Fig. 2 to 4.Therefore, the speed-changing chain 47 of chain wheel set 40 is chosen as the work sprocket wheel.Therefore, chain C hangs over and drives on input sprocket 32 and the speed-changing chain 47, and they lay respectively at the position shown in the solid line in Fig. 3 and 4.Bent axle 12 along hand of rotation A0 rotation forward when the cyclist drives pedal drives this driving input sprocket 32 rotations by free-wheel clutch 30.Drive input sprocket 32 by chain C and with by two sprocket wheels 32 and 47 speed changes of determining recently driven in rotation speed-changing chain 47, output shaft 15 and drive output chain gear 17.And, drive output chain gear 17 and make driven sprocket 18 and rear wheel Wr rotate by chain 19.

When being operating as, variable-speed operation parts 61 make low speed-changing chain 41 to 46 (for example speed-changing chain 41) when being chosen as the work sprocket wheel, in order to change shift position from above-mentioned home position, the parallelogram linkage 73 of inner cable 62b operation derailer 70.Therefore, parallelogram linkage 73 makes retainer H, guide pulley 72, arm R and tension pulley block 82 in axial direction to left movement with radially outwards move from rotation centerline L3.Therefore, retainer, guide pulley 72, arm R and tension pulley block 82 occupy first shift position, and this first shift position is the shift position of being represented by the two dash lines of the dash among Fig. 2 to 4.With guide pulley 72 and tension pulley block 82 tensile force on the chain C of left movement make to drive input sprocket 32 in axial direction along the main shaft 12a of bent axle 12 to left movement.Therefore, driving input sprocket 32 occupies the position shown in the two dash lines of dash in Fig. 3 and 4.At this moment, chain C hangs on the speed-changing chain 41, and speed-changing chain 41 is connected with driving input sprocket 32 by driven chain C.

In addition, be operable to when selecting a speed-changing chain 42 to 47 (this sprocket wheel is arranged in than first shift position shift position faster) parallelogram linkage 73 of inner cable 62b operation derailer 70 when variable-speed operation parts 61.Therefore, parallelogram linkage 73 makes retainer H, guide pulley 72, arm R and tension pulley block 82 in axial direction move right and radially inwardly moves towards rotation centerline L3.Tensile force on the chain C that moves right along guide pulley 72 and tension pulley block 82 makes that driving input sprocket 32 moves right along main shaft 12a.Simultaneously, chain C hangs on the speed-changing chain of having selected from speed-changing chain 42 to 47.

Like this, the derailer of operating in response to the variable speed operation that is undertaken by speed changing operating mechanism 60 makes chain from speed-changing chain 41 to 47 be converted to another.Therefore, the converter speed ratio of bicycle B operation determines that by selected work sprocket wheel and driving input sprocket 32 chain C hangs over this work sprocket wheel and drives on the input sprocket 32.

In addition, for example rotate backward and bicycle when being in backward the state of operation when speed-changing chain 41 to 47, perhaps stop and bicycle B when stopping when speed-changing chain 41 to 47, in other words when speed-changing chain 41 to 47 does not rotate forward, if carry out variable speed operation by variable-speed operation parts 60, chain C may break away from the orbit plane P1 of guide pulley 72 in some cases, perhaps breaks away from the orbit plane P2 of tension pulley block 82 in other cases.At this moment, may form derailing portion C 11, C12, C13 and C14.

In some cases, be used for making the derailing portion C 11 of chain C and C13 (they derail from the orbit plane P1 of guide pulley 72) to mesh the peripheral wall 80a that recovery device comprises extendible portion 106 and spring housing portion 80 with guide pulley 72 ingears, they in axial direction are arranged in left side and the right side of the orbit plane P1 of guide pulley 72 respectively, and they in axial direction extend along the direction of deorbit plane P separately 1.Therefore, extendible portion 106 and peripheral wall 80a guide derailing portion C 11 and C13 (this derailing portion C 11 and C13 have arrived respectively on extendible portion 106 and the peripheral wall 80a) respectively, like this, because the tensile force that when speed-changing chain 41 to 47 rotates forward, on chain C, produces, derailing portion C 11 and C13 slide towards orbit plane P1 on extendible portion 106 and peripheral wall 80a respectively, and mesh with guide pulley 72.

Therefore, even chain C when speed-changing chain 41 to 47 rotates backward or stops since guide pulley 72 and tension pulley block 82 (passing through variable speed operation) in axial direction move when de-orbiting plane P 1, derailing portion C 11 and C13 are respectively by extendible portion 106 and peripheral wall 80a guiding, like this, when extendible portion 106 and peripheral wall 80a make that guide pulley 72 and tension pulley block 82 in axial direction move to the left or to the right, derailing portion C 11 and C13 slide on the guiding surface 80b of the guiding surface 107 of extendible portion 106 and peripheral wall 80a respectively, and then with guide pulley 72 engagements.Therefore, when speed-changing chain 41 to 47 rotated forward, will prevent to derail portion C 11 and C13 were stuck between guide pulley 72 and the first arm 100 and between the guide pulley 72 and second arm 120.In addition, prevent to derail portion C 11 and C13 are positioned at guide pulley 72 sidepieces and are positioned at the radially inner position of swing-around trajectory 72c from guide pulley 72.This makes chain C to move.Therefore, even rotate backward and bicycle B carries out variable speed operation when moving backward when speed-changing chain 41 to 47, chain C can not be stuck in (in other words, chain C can not stagnate) between guide pulley 72 and the speed-changing chain group 41 to 47 yet.When speed-changing chain 41 to 47 rotated forward, chain C returned the state with guide pulley 72 positive engagement.

Therefore, derailing portion C 11 and C13 are easy to return and guide pulley 72 ingear states.No matter how speed-changing chain 41 to 47 rotates, can carry out variable speed operation, comprise the situation of not rotating forward, for example the situation of rotating backward when speed-changing chain 41 to 47 when speed-changing chain 41 to 47.Therefore, can carry out speed change according to variable speed operation.

Aforementioned pulley bearing parts comprise the first retainer part 76 and the second retainer part 77 and the first arm part 100 and second arm portion 120.The first retainer part 76 and the second retainer part, 77 rotatably mounted guide pulley 72, and supporting part 78 is arranged between them.The first arm part 100 and second arm portion, 120 rotatably mounted tension pulley blocks 82 (this tension pulley block is by supporting part 78 supportings of retainer H, and this tension pulley block applies tensile force on chain), and supporting part 84 is arranged between them.Extendible portion 106 is integrally molded with the first arm part 100.Peripheral wall 80a is the peripheral wall that is used to hold the spring housing portion 80 of tensioning spring 83, and this tensioning spring produces and is used for tension pulley block 82 is pushed against spring force on the chain C.Therefore, extendible portion 106 and peripheral wall 80a provide by utilizing the first arm part 100 and spring housing portion 80 (they are parts of supporting tension pulley block 82).This does not need to prepare to be specifically designed to the parts that constitute extendible portion 106 and peripheral wall 80a.Therefore, will prevent to increase the part count among the transmission system T (comprising the engagement recovery device), and reduce the cost of transmission system T.

Form like this by the folding extendible portion 106 that forms, be that extendible portion 106 has guiding surface 107, this guiding surface smoothly stretch into guide pulley 72 facing surfaces 104b and 105b in, this surface 104b and 105b are respectively in two neighboring parts 104 and 105.This makes 11 smooth motions of derailing portion C to guiding surface 107, and returns and guide pulley 72 ingear states.Like this, will improve make derailing portion C 11 return rapidity and the reliability with guide pulley 72 ingear states, and therefore improve rapidity and the reliability that carries out speed change.

Speed-changing chain 41 to 47 is arranged to like this, promptly from speed-changing chain with minimum diameter in axial direction left order to speed-changing chain with maximum gauge. extendible portion 106 and peripheral wall 80a are arranged in left side and the right side of orbit plane P1.Compare with guiding surface 80b peripheral wall 80a, that derailing portion C 13 can arrive, guiding surface 107 extendible portion 106, that derailing portion C 11 can arrive is arranged in the position littler apart from d1 from the rotation centerline L4 of guide pulley 72.This disappears except when guide pulley 72 interference between extendible portion 106 and each speed-changing chain 41 to 47 when left movement.Therefore, guarantee to carry out the reliability of variable speed operation.In addition, guide pulley 72 and each speed-changing chain 41 to 47 can be arranged to more close each other.This can make transmission system T miniaturization.And, changed the reliability that carries out variable speed operation.In addition, this can make speed change smoothly carry out.

As if extendible portion 106 is arranged to extend to the position that makes that when seeing from the side connecting bridge 103 overlaps with tension pulley block 82 continuously from the side directed part 101 of guide pulley.Extendible portion 106 width W 3 in axial direction is chain C width W 4 in axial direction no better than.This makes that extendible portion 106 can be as the enhancing rib of the first arm part 100.Therefore, the rigidity of the first arm part 100 of supporting tension pulley block 82 increases.In addition, guarantee to make derailing portion C 11 to be back into and guide pulley 72 ingear guiding functions.And extendible portion 106 width in axial direction can be littler.This makes extendible portion 106 miniaturization in axial direction.This makes guide pulley 72 and each speed-changing chain 41 to 47 can be arranged in axial direction more close each other.Therefore, transmission system T miniaturization in axial direction.

Arm R comprises the first arm part 100 and second arm portion 120.The first arm part 100 is arranged in axial direction with respect to the orbit plane P2 of the orbit plane P1 of guide pulley 72 and tension pulley block 82 left.Second arm portion 120 is arranged in axial direction orbit plane P2 with respect to the orbit plane P1 of guide pulley 72 and tension pulley block 82 with right.The first arm part 100 provides extendible portion 106, and second arm portion 120 provides the peripheral wall 80a of spring housing portion 80, and like this, peripheral wall 80a is in axial direction near second arm portion 120.Second arm portion 120 in axial direction is arranged between guide pulley 72 and the peripheral wall 80a.Outermost edges 124a is a part second arm portion radially.The rotation centerline L4 of outermost edges 124a to the guiding surface 80b that equals peripheral wall 80a apart from d2 of the rotation centerline L4 of guide pulley 72 to guide pulley 72 apart from d2.Therefore, derailing portion C 13 is by peripheral wall 80a guiding, like this, and the smooth motion on guiding surface 80b of derailing portion C 13, and can not be subjected to the interference of second arm portion 120.Therefore, derailing portion C 13 can be returned and guide pulley 72 ingear states.Therefore, derailing portion C 13 is returned with the rapidity of guide pulley 72 ingear states and reliability and is improved.And the rapidity and the reliability that carry out speed change improve.And, because inclined surface 125 is formed in the neighboring part 124 of the side directed part 121 of guide pulley in second arm portion 120, therefore, derailing portion C 13 easier and guide pulley 72 engagements of on guiding surface 80b, having moved.

The width W 5 that the width W 3 of extendible portion 106 is in axial direction occupied by two speed-changing chains (these two speed-changing chains are in axial direction adjacent one another are) no better than.Peripheral wall 80a width W 8 in axial direction is greater than the width W 3 of extendible portion 106.Therefore, owing to extendible portion 106 and peripheral wall 80a guarantee to make derailing portion C 11 and C13 to return the guiding function with guide pulley 72 ingear states.In addition, first extendible portion 106 width W 3 in axial direction can become littler.This makes extendible portion 106 miniaturization in axial direction.In addition, guide pulley 72 and each speed-changing chain 41 to 47 can be arranged in axial direction more close each other.This makes transmission system T miniaturization in axial direction.And even when the width that in axial direction move of derailing portion C 13 is bigger, peripheral wall 80a also can make derailing portion C 13 be back to and guide pulley 72 ingear states, like this, and on the derailing portion C 13 reliable arrival peripheral wall 80a.Therefore, improved and make derailing portion C 13 return reliability with guide pulley 72 ingear states.In addition, also improved the reliability that carries out speed change.

When the extendible portion 106 that divides 105 than the minor diameter peripheral edge portion is arranged to relatively large diameter neighboring part 104 radially inwardly the time, and when the extendible portion 106 that divides 105 than the minor diameter peripheral edge portion is positioned at more close rotation centerline L4, divide 105 extendible portion 106 to make derailing portion C 11 return and guide pulley 72 ingear states than the minor diameter peripheral edge portion, like this, when even work speed-changing chain when variable speed operation makes chain C be converted to faster shift position after speed change and the external diameter between the work speed-changing chain before the speed change differ greatly, derailing portion C 11 also reliably arrives on the extendible portion 106, and can not make derailing portion C 11 break away from extendible portion 106.Therefore, guide pulley 13 is back to the reliability of guide pulley 72 ingear states and improves.Improved the reliability that carries out speed change in addition.

The first arm part 100 and second arm portion 120 provide engagement respectively and recover leader 110 and 130 near the part of the introducing chain C of tension pulley block 82.Engagement recovers leader 110 to be made from the chain C derailing portion C 12 and tension pulley block 82 engagements of the orbit plane P2 derailing of tension pulley block 82. engagement recovers leader 130 to be made and to mesh from the chain C derailing portion C 14 and the tension pulley block 82 of the orbit plane P2 derailing of tension pulley block 82.Engagement recovers the leader 110 whole derailing portion C 12 of guiding like this, i.e. engagement recovers leader 110 and whole derailing portion C 12 is positioned to radially outside with respect to the swing-around trajectory 82c of tension pulley block 82, and because the tensile force of chain C, engagement recovers leader 110 makes whole derailing portion C 12 towards orbit plane P2 motion, then with tension pulley block 82 engagements.Engagement recovers the leader 130 whole derailing portion C 14 of guiding like this, i.e. engagement recovers leader 130 and whole derailing portion C 14 is positioned to radially outside with respect to the swing-around trajectory 82c of tension pulley block 82, and because the tensile force of chain C, engagement recovers leader 130 makes whole derailing portion C 14 towards orbit plane P2 motion, then with tension pulley block 82 engagements.

Therefore, even when speed-changing chain 41 to 47 does not rotate forward, (do not comprise the situation that speed-changing chain 41 to 47 stops, particularly when speed-changing chain 41 to 47 stops) owing to variable speed operation makes tension pulley block 82 in axial direction move to make the chain C plane P 2 that de-orbits, the derailing portion C 12 of chain C and C14 also recover leader 110 and 130 guiding by engagement respectively, and therefore return and tension pulley block 82 ingear states.This prevent to derail portion C 12 and C14 be stuck between tension pulley block 82 and the first arm part 100 and be stuck in tension pulley block 82 and second arm portion 120 between.In addition, this prevent to derail portion C 12 and C14 are positioned at the radial direction inboard of the swing-around trajectory 82c of the left side of tension pulley block 82 and right side and tension pulley block 82 respectively.Like this, chain C can move.Therefore because variable speed operation and recovered leader 110 and 130 guiding by engagement respectively from the derailing portion C 12 and the C14 of the orbit plane P2 of tension pulley block 82 derailing, thereby make derailing portion C 12 and C14 once more with tension pulley block 82 engagements.Like this, chain C can move, and this makes derailing portion C 12 and C14 is easier returns and tension pulley block 82 ingear states.Like this, the state of rotation also can carry out variable speed operation when (comprising halted state) when speed-changing chain 41 to 47 is in not forward.Therefore, can carry out speed change according to variable speed operation.

Derailer 70 comprises guide pulley 72 and retainer H.Guide pulley 72 guiding hang over the chain C on the work sprocket wheel of having selected from speed-changing chain 41 to 47.The rotatably mounted guide pulley 72 of retainer H, and can in axial direction move with arm R.Arm R comprises a pair of arm portion 100 and 120.Arm portion 100 is arranged in the axial direction left side of tension pulley block 82 and guide pulley 72.Arm portion 120 is arranged in the axial direction right side of tension pulley block 82 and guide pulley 72.Side directed part 102 of tension pulley block and the side directed part 101 of guide pulley are formed in the arm portion 100.Side directed part 122 of tension pulley block and the side directed part 121 of guide pulley are formed in the arm portion 120.The side directed part 102 of tension pulley block and 122 prevents that the part that chain C hangs on the tension pulley block 82 breaks away from tension pulley block.The side directed part 101 of guide pulley and 121 is the supporting parts by retainer H supporting.In axial direction at the interval W1 between two side directed parts 101 of guide pulley and 121 greater than the interval W2 between two side directed parts 102 of tension pulley block and 122 in axial direction.

This can increase the bending rigidity of the side directed part 101 of each guide pulley and 121, and the side directed part 101 of this guide pulley and 121 is such parts, and promptly derailer 70 masterpiece that will be used to arm R is in axial direction moved is used in above it.Therefore, can be made for weight lighter for the side directed part 101 of guide pulley and 121.In addition, when the axial direction between the side directed part 102 of the tension pulley block of arm R and 122 is made for more hour at interval, the side directed part of tension pulley block can be arranged to more close tension pulley block 82.This makes and is reliably returned and tension pulley block 82 ingear states by engagement recovery leader 110 and 130 derailing portion C 12 and the C14 that guide respectively.Therefore, improved and make derailing portion C 12 and C14 be back to reliability with tension pulley block 82 ingear states.

Each engagement recovers leader 110 and 130 scopes that form along circumferential direction are such scopes, when seeing from the side, it makes around the rotation centerline of tension pulley block 82 along the angle θ 1 of the relative centre plane P3 of the A0 of hand of rotation forward of tension pulley block 82 no better than around the rotation centerline of the tension pulley block 82 angle θ 2 along the relative centre plane P3 of hand of rotation backward of tension pulley block 82.Therefore, can guarantee fully that each engagement recovers leader 110 and 130 scopes along circumferential direction formation.This makes derailing portion C 12 and C14 can more easily be back to and tension pulley block 82 engagements.Therefore, improved derailing portion C 12 and C14 are back to and tension pulley block 82 ingear reliability.And, recovering in the leader 110 and 130 in engagement, the point of action that applies corresponding power with respectively derail portion C 12 and C14 that engagement recovers that leader 110 contacts with 130 can be made for more close centre plane P3.The moment that is caused by power, act on arm portion 100 and 120 respectively can reduce.It is too big that this makes that arm portion 100 and 120 does not need, and also need not gain in weight for the torsional rigidity that improves each arm portion 100 and 120.Therefore, can be made for weight lighter for arm portion 100 and 120.

Arm R comprises a pair of arm portion 100 and 120.Arm portion 100 in axial direction is arranged in the left side of tension pulley block 82, and engagement recovery leader 110 is formed in the arm portion 100.Arm portion 120 in axial direction is arranged in the right side of tension pulley block 82, and engagement recovery leader 130 is formed in the arm portion 120.Engagement recovers leader 110 and 130 guiding surface 112 and 132 respectively.Derailing portion C 12 contacts with 132 with guiding surface 112 respectively with C14.Guiding surface 112 in axial direction and along the direction of deorbit plane P 2 extends left.Guiding surface 132 in axial direction and along the direction of deorbit plane P 2 extends to the right.In guiding surface 112, end sections 112a is in axial direction near tension pulley block 82.In guiding surface 132, end sections 132a is in axial direction near tension pulley block 82.End sections 112a and 132a are positioned at the position much at one, inner periphery C4a present position with chain C (this chain C and tension pulley block 82 engagements).This makes derailing portion C 12 and C14 arrive respectively on guiding surface 112 and 132 at an easy rate.The start-up portion C12a of each derail portion C 12 and C14 and C14a lay respectively at along tension pulley block 82 forward hand of rotation A0 the position and recover in the leader 110 and 130 in engagement respectively, and prevent part 111 and 131 near derailing respectively.Therefore, start-up portion C12a and C14a can be positioned to as far as possible away from driving input sprocket 32 parts that chain C is drawn.This has reduced the degree of reversing of chain C, and this reverses by tension pulley block 82 and in axial direction moves and cause.This has reduced the resistance that is produced by chain C when carrying out variable speed operation.Therefore, reduced the resistance that produces by chain C because chain C reverses.Like this, variable speed operation can more easily carry out.

The housing parts 21 of transmission system T provides projection 56, and this projection 56 is in such position, and promptly as if when seeing from the side, it makes projection 56 overlap with the portion C 1 that hangs over the chain C on the speed-changing chain.Portion C 1 and speed-changing chain 41 engagements, this speed-changing chain 41 are in axial direction near the sprocket wheel that closes on of housing 20 in speed-changing chain 41 to 47.Projection 56 is regulated chain C in axial direction with the direction motion near first housing parts 21.Projection 56 prevents that by it and contacting of chain C chain C breaks away from speed-changing chain 41.Therefore, when carrying out variable speed operation on speed-changing chain 41, projection 56 prevents that chain C from axial direction surpassing speed-changing chain 41 and move.Like this, chain C will can not break away from speed-changing chain 41.This need not be provided with chain C and guide pulley 72 position in axial direction in response to shift position with degree of precision based on variable speed operation.Therefore, this simple structure can prevent that chain C is owing to quick variable speed operation breaks away from speed-changing chain 41.

The projection 56 and first housing parts 21 are integrally molded, and like this, projection 56 in axial direction hangs over the portion C 1 on the speed-changing chain and protrudes towards chain C, and this does not need to prepare the special-purpose member that is used to constitute projection 56.Therefore, the part count of transmission system T will reduce, and the cost of transmission system T also will reduce.In addition, can be made for weight lighter for transmission system T.

First housing parts 21 provides internal rib 57, and like this, internal rib 57 is in axial direction protruded.Internal rib 57 is outwards protruded from projection 56 along the axial direction of speed-changing chain 41.Top surface 57a internal rib 57, in axial direction is positioned at the position much at one, top surface 56d present position with projection 56, and this projection 56 is regulated chain C motion in axial direction by contacting with chain C.Therefore, internal rib 57 has further increased the rigidity of first housing parts 21.In addition, even when the part of chain C radially stretches out above projection 56, will prevent that the outwardly directed part of chain C from axial direction surpassing projection 56 motions.Therefore, improved the effect that prevents the chain derailing more.

Projection 56, internal rib 57 and external rib 58 are integrally molded with first housing parts of being made by flat-form material 21.Therefore, improved the rigidity of first housing parts 21.

In addition, projection 56 provides second portion 56b.Therefore, even carry out variable speed operation on speed-changing chain 41 when forming stagnation portion C 2 on chain C, projection 56 can prevent that also chain C from surpassing speed-changing chain 41 and in axial direction moving.Therefore, chain C will can not break away from speed-changing chain 41.

To introduce the example of the localized variation form of the foregoing description below, will concentrate to introduce to change structure.

The housing of transmission system T can be made by synthetic resin.Above-mentioned housing is such housing, and wherein sealing is formed for holding the chamber of speed-changing mechanism M1, derailer 70 and tensioner 74.In fact, housing can be to make accommodating chamber form to be opened on housing in the outside air, for example comprises the housing of the axial direction left part that covers chain wheel set 40 at least.

Extendible portion 106 can tilt like this, and promptly when extendible portion 106 radially stretched out, this extendible portion 106 in axial direction extended along the direction of deorbit plane P 1.In addition, guiding surface 107 can tilt like this, and promptly when guiding surface 107 radially stretched out, this guiding surface 107 in axial direction extended along the direction of deorbit plane P 1.Extendible portion 106 can be handled and integrally molded with the first arm part 100 by ground or casting.Engagement recovers that leader 110 and 130 can be handled by ground or casting respectively and integrally molded with the first arm part 100 and second arm portion 120.Engagement recovers leader 110 and 130 and can extend abreast with rotation centerline L5.In addition, guiding surface 112 and 132 can extend abreast with rotation centerline L5.

The outermost edges 124a of the neighboring part 124 in second arm portion 120 can be positioned at such position, promptly it from the distance of rotation centerline L4 less than distance d2.

Projection can be formed at along circumferential direction or part radially.

In the aforementioned embodiment, the sprocket wheel of public use comprises driving input sprocket 32, and speed-changing chain 41 to 47 constitutes driven sprockets.But, a plurality of speed-changing chains can be made of a plurality of drive sprockets.The sprocket wheel of public use can be made of driven sprocket, and the sprocket wheel that is used for speed change hangs between the sprocket wheel and speed-changing chain of public use.

Chain wheel set can be arranged on the output shaft, and this output shaft is arranged on the axis identical with the rotation centerline of rear wheel, and chain wheel set can be made of the driven sprocket that is used to export.Transmission system T also can be arranged on the machine except bicycle.

Although introduced the present invention with reference to a plurality of specific embodiments, above stated specification just is illustrated, rather than limits.It will be appreciated by those skilled in the art that preferred embodiment can have multiple version.All these versions in the claim scope all will be in scope and spirit of the present invention.

Claims (14)

1. transmission system comprises:

Chain;

A plurality of speed-changing chains, these speed-changing chains are in axial direction to be disposed in order in the mode of sidepiece from speed-changing chain with big external diameter to the speed-changing chain with less external diameter; And

Mapping device is used for making described chain convert another sprocket wheel of selecting to from a sprocket wheel of described a plurality of speed-changing chains from described a plurality of speed-changing chains in response to variable speed operation, and this mapping device comprises:

Guide pulley, this guide pulley can in axial direction be moved, and this guide pulley can be operated and with chain guide another selected sprocket wheel to described a plurality of speed-changing chains; And

The pulley bearing parts, rotatably mounted this guide pulley of these pulley bearing parts, chain is on this guide pulley, and these pulley bearing parts can in axial direction move by variable speed operation;

Wherein, the pulley bearing parts are provided with the engagement recovered part, are used for making the derailing part and the engagement of this guide pulley of having derailed from the orbit plane of guide pulley of this chain;

Wherein, the engagement recovered part comprises first extendible portion and second extendible portion, this first extendible portion and second extendible portion in axial direction be arranged in guide pulley orbit plane both sides and in axial direction opposite side, and extend along the direction of the orbit plane that leaves guide pulley;

Wherein, each extendible portion can operate and guide this chain arrive derailing part on this extendible portion, like this, because the tensile force of chain, the derailing part of chain is slided on this extendible portion, and moves towards the orbit plane of this guide pulley, meshes with guide pulley then; And

Wherein, guiding surface in first extendible portion, that the derailing part can arrive on it is positioned at such position, promptly with second extendible portion in, guiding surface that derailing part can arrive on it compares, it is littler from the distance of the rotation centerline of guide pulley.

2. transmission system according to claim 1, wherein, transmission system comprises tension pulley block,

Wherein, the pulley bearing parts comprise: retainer is used for rotatably mounted described guide pulley; And arm, being used for rotatably mounted tension pulley block, this tension pulley block is supported by retainer, and this tension pulley block applies tensile force to chain;

Wherein, first extendible portion and arm are integrally molded; And

Wherein, second extendible portion comprises spring housing portion, and this spring housing portion is used to hold tensioning spring, so that produce spring force, this spring force is used for tension pulley block is pushed against chain.

3. transmission system according to claim 2, wherein:

When seeing from the side, first extendible portion extends to and makes the extendible portion of winning seem the position that overlaps with tension pulley block; And

Wherein, first extendible portion width in axial direction equals chain width in axial direction.

4. transmission system according to claim 2, wherein:

Described arm comprises the first arm partial sum second arm portion, one of them arm portion in axial direction is arranged in corresponding first side of the orbit plane of guide pulley and tension pulley block, and another arm portion in axial direction is arranged in corresponding second side of the orbit plane of guide pulley and tension pulley block;

The first arm partly provides first extendible portion;

Second arm portion provides spring housing portion, like this, and in axial direction contiguous second arm portion of spring housing portion; And

Second arm portion in axial direction is arranged between guide pulley and the spring housing portion, second arm portion outermost edges radially is positioned at such position, promptly compare with guiding surface spring housing portion, that the derailing part can arrive on it, it is equal or littler from the distance of the rotation centerline of guide pulley.

5. transmission system according to claim 4, wherein:

First extendible portion width in axial direction equals the width in axial direction that occupied by two speed-changing chains in these a plurality of speed-changing chains, and these two speed-changing chains are in axial direction adjacent one another are;

Second extendible portion width in axial direction is greater than first extendible portion width in axial direction.

6. transmission system comprises:

Chain;

A plurality of speed-changing chains, these speed-changing chains are in axial direction arranged; And

Mapping device is used for making chain convert a sprocket wheel of selecting to from a sprocket wheel of described a plurality of speed-changing chains from described a plurality of speed-changing chains in response to variable speed operation;

This mapping device comprises:

Tension pulley block is used for applying tensile force to chain,

Arm, rotatably mounted this tension pulley block of this arm, the motion in axial direction of this arm owing to variable speed operation;

Wherein, introducing near the tension pulley block part of chain, this arm provides engagement and recovers leader, is used for making respectively the derailing part of chain of the orbit plane that broken away from tension pulley block to mesh with tension pulley block;

Engagement recovers leader and guides the derailing part respectively, like this, whole derailing part is positioned in axial direction from the swing-around trajectory of the outermost periphery of tension pulley block outside, and the derailing part is because the tensile force of chain and towards the orbit plane motion of tension pulley block, meshing with tension pulley block then;

Wherein: a centre plane is defined as the plane of the rotation centerline of the rotation centerline that comprises tension pulley block and guide pulley; And

The scope that forms each engagement recovery leader along circumferential direction is such scope, it comprises when seeing from the side that with respect to described centre plane along the direction of rotation forward first angle around the rotation centerline of tension pulley block, this first angle equals with respect to described centre plane along second angle of contrarotation direction around the rotation centerline of tension pulley block.

7. transmission system according to claim 6, wherein, mapping device comprises:

Guide pulley is used for guiding the chain that hangs on the selected described sprocket wheel of described a plurality of speed-changing chain; And

Retainer, rotatably mounted this guide pulley of this retainer, and this retainer can in axial direction move with described arm;

Wherein, this arm comprises a pair of arm portion, and an arm portion in axial direction is arranged in corresponding first side of tension pulley block and guide pulley, and another arm portion in axial direction is arranged in corresponding second side of tension pulley block and guide pulley;

Each arm portion comprises: the side directed part of tension pulley block, the side directed part of this tension pulley block are used to prevent that the part that hangs on the tension pulley block of chain breaks away from; And supporting part, this supporting part is supported by retainer; And

In axial direction in axial direction the interval between two tension pulley block side guide are divided is wideer at the ratio of the interval between two supporting parts.

8. transmission system according to claim 6, wherein:

Described arm comprises a pair of arm portion, and this is arranged in axial direction opposite side with respect to tension pulley block respectively to arm portion, and engagement recovers leader and is formed at this respectively in the arm portion;

Each engagement recovers leader and comprises guiding surface, and a derailing part contacts with this guiding surface, and this guiding surface in axial direction and along the direction on deorbit plane extends;

In each guiding surface in axial direction the end of close tension pulley block be positioned at the position identical with the residing position of inner periphery of tension pulley block ingear chain in.

9. transmission system, this transmission system are packed in the housing, and it comprises:

Chain;

A plurality of speed-changing chains, these speed-changing chains are in axial direction arranged; And

Mapping device is used for making chain convert a sprocket wheel of selecting to from a sprocket wheel of described a plurality of speed-changing chains from described a plurality of speed-changing chains in response to variable speed operation,

This mapping device comprises:

Guide pulley, this guide pulley can in axial direction be moved, and guides the chain that hangs on the described sprocket wheel selected in described a plurality of speed-changing chain, and this guide pulley comprises the orbit plane of described guide pulley;

The pulley bearing parts, the rotatably mounted described guide pulley of these pulley bearing parts, chain is wrapped on this guide pulley, and these pulley bearing parts can in axial direction move by variable speed operation;

Tension pulley block is used for applying tensile force to chain; And

Arm, the rotatably mounted described tension pulley block of this arm, the motion in axial direction of this arm owing to variable speed operation;

Wherein, the pulley bearing parts provide the engagement recovered part, are used for making the derailing part and the engagement of this guide pulley of having derailed from the orbit plane of guide pulley of chain;

Described arm provides engagement and recovers leader, the derailing part and the engagement of this tension pulley block that are used for making respectively the orbit plane from tension pulley block of chain to derail;

This mapping device also comprises connecting rod mechanism, this connecting rod mechanism at one end rotatably is fixed on the housing, be fixed on the retainer at the other end, this connecting rod mechanism can be operated and make retainer in axial direction move with the edge direction vertical with axial direction with guide pulley in response to variable speed operation, and this connecting rod mechanism comprises a pair of elongated connecting rod.

10. transmission system according to claim 9, wherein: the engagement recovered part comprises first extendible portion and second extendible portion, this first extendible portion and second extendible portion in axial direction are arranged in the opposite side of the orbit plane of guide pulley, and extend along the direction and the axial direction of the orbit plane that leaves guide pulley;

Each extendible portion guiding chain arrive derailing part on this extendible portion, like this, because the tensile force of chain, the derailing part of chain is slided on this extendible portion, and towards the orbit plane motion of guide pulley, meshes with guide pulley then.

11. transmission system according to claim 9, wherein: described arm provides engagement and recovers leader, and this engagement recovers leader near the part of the tension pulley block of introducing chain, and

Engagement recovers leader and guides the derailing part respectively, like this, whole derailing part is positioned in axial direction from the swing-around trajectory of the outermost periphery of tension pulley block outside, and because the tensile force on chain, the derailing part meshes with tension pulley block then towards the orbit plane motion of tension pulley block.

12. a driving device that is used for bicycle comprises:

Hollow shell;

Bent axle, this bent axle pass described hollow shell and extend, and can be rotated to support on this hollow shell;

Drive input sprocket, this driving input sprocket operationally is installed on the described bent axle, can rotate with this bent axle simultaneously, and described driving input sprocket is arranged in described enclosure interior;

Output shaft, this output shaft has the gear support part, and this gear support partly is arranged in the described hollow shell, and can be rotated to support on this hollow shell, and described output shaft has central axis, and also comprises from the outward extending outer end portion of described housing;

A plurality of isolated speed-changing chains, these speed-changing chains operationally are installed on the described output shaft, rotate with this output shaft simultaneously, described speed-changing chain is arranged in described enclosure interior, and in axial direction to be disposed in order in the mode of sidepiece from speed-changing chain with big external diameter to the speed-changing chain with less external diameter;

Chain, this chain extends between described driving input sprocket and a selected described speed-changing chain;

Drive output chain gear, this driving output chain gear operationally is installed in the outer end portion of described output shaft, can rotate with it simultaneously, and described driving output chain gear is arranged in described outside;

Mapping device is used for making chain convert another selected described a plurality of speed-changing chain sprocket wheel to from a sprocket wheel of described a plurality of speed-changing chains in response to variable speed operation, and this mapping device comprises:

Guide pulley, this guide pulley can be moved by orbit plane along the basic direction parallel with the central axis of output shaft, and this guide pulley can be operated and with chain guide extremely in described a plurality of speed-changing chains on selected another sprocket wheel;

And the pulley bearing parts, the rotatably mounted guide pulley of these pulley bearing parts, chain is wrapped on this guide pulley, and these pulley bearing parts can in axial direction move by variable speed operation;

Wherein, the pulley bearing parts provide the engagement recovered part, are used for helping during from the derailing of the orbit plane of guide pulley when a part of chain the derailing part and the engagement of this guide pulley of guiding chain;

This engagement recovered part comprises first and second extendible portions of the orbit plane opposite side in axial direction that is arranged in guide pulley; Wherein, guiding surface in first extendible portion, that the derailing part can arrive on it is positioned at such position, promptly with second extendible portion in, guiding surface that derailing part can arrive on it compares, it is littler from the distance of the rotation centerline of guide pulley.

13. a bicycle comprises transmission system as claimed in claim 1.

14. a bicycle comprises driving device as claimed in claim 12.

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