JP2004001665A - Continuously variable transmission for bicycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a continuously variable transmission for a bicycle capable of rapidly changing speed even in the case of a large change of a variable speed ratio while attaining miniaturization and weight reduction of a support member which constitutes a variable speed operating mechanism for changing the variable speed ratio steplessly, and furthermore attaining miniaturization and weight reduction of the continuously variable transmission. <P>SOLUTION: This continuously variable transmission T for the bicycle is provided with a variable speed mechanism M3 having link units U1-U4 for converting the rotation of an input shaft 15 driven by a crankshaft 12, into swinging motion; a one-way clutch 36 for converting the swinging motion into the rotation of an output shaft 16; and a variable speed operating mechanism M4 having a variable speed operating link 54 pivoted to the link units U1-U4 and a pivot 53 to change the rotating speed of the output shaft 16 steplessly by swinging the pivot 53 around a center shaft 52 together with the support member 51 by operating force transmitted through a transmission mechanism. The transmission mechanism has a link mechanism including a link 62 pivoted to the pivot, and the operating force is transmitted to the pivot 53 through the link mechanism. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a plurality of link units for converting a rotational motion of an input shaft into a oscillating motion, a one-way clutch for converting the oscillating motion into a rotational motion of an output shaft, and continuously changing the rotational speed of the output shaft. The present invention relates to a continuously variable transmission for a bicycle, comprising:
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as this type of a continuously variable transmission for a bicycle, one disclosed in Japanese Patent Application Laid-Open No. 54-120146 is known. This continuously variable transmission is provided on a crankshaft that is rotationally driven by torque transmitted from a driving sprocket of a pedal to a driven sprocket via a chain, a crank rod pivotally supported by an eccentric pin of the crankshaft, and an intermediate shaft. One-way clutch, a feed rod one end of which is pivotally connected to a drive-side member of the one-way clutch and the other end of which is pivotally connected to a crank rod, an output shaft to which rotation of an intermediate shaft is transmitted, a crank rod and a feed rod. A pivot pin integrally supporting the pivot, and a link pivotally connected at one end to the coupling pin and at the other end to the pivot. Then, the rotating piece rotated by the operating force for shifting changes the position of the pivot, whereby the gear ratio is continuously changed. For this purpose, the turning piece is formed with a toothed portion that meshes with a control gear provided on a control panel that operates according to the rotation speed of the output shaft. Is displaced by the operating force applied to.
[0003]
[Problems to be solved by the invention]
By the way, in the above-mentioned prior art, since the operating force for displacing the rotating piece is applied to the toothed part formed on the rotating piece, it is necessary to provide a part for forming the toothed part on the rotating piece. There is a problem that the moving piece is enlarged and its weight is increased. Particularly, when the gear ratio is changed over a wide range, the length of the tooth portion is increased, and the rotating piece becomes larger and The weight gain is even more pronounced. Further, the operating force applied to the rotating piece is transmitted through meshing between the control gear formed on the outer periphery of the cylindrical portion formed integrally with the control panel and the toothed portion, where the operating force is generated, so that the gear ratio is changed. It is difficult to perform a quick shift during an operation in which is greatly changed.
[0004]
The present invention has been made in view of such circumstances, and reduces the size and weight of a support member that constitutes a speed change operation mechanism for continuously changing a speed ratio, thereby reducing the size and weight of a transmission. It is an object of the present invention to provide a continuously variable transmission for a bicycle that can perform a quick shift even when the gear ratio is largely changed.
[0005]
Means for Solving the Problems and Effects of the Invention
A first aspect of the present invention provides a speed change mechanism including a plurality of speed change links, each of which includes a plurality of speed change links, and a plurality of link units for converting a rotational motion of an input shaft rotationally driven by a pedal-type crankshaft into a rocking motion, A one-way clutch connected to each of the link units for converting a swinging motion of the link unit into a rotary motion of an output shaft, a transmission mechanism for transmitting an operating force for a shift operation, and a pivot are integrally supported. A transmission member which is pivotally connected to the link unit at one end and pivotally connected to the pivot at the other end. A step for continuously changing the rotation speed of the output shaft by swinging the pivot together with the support member about the center axis by an operating force transmitted through the transmission mechanism. And a transmission mechanism having a link mechanism including a link pivotally connected to the pivot, and an operation force is transmitted to the pivot via the link mechanism. It is a continuously variable transmission for bicycles.
[0006]
As a result, the operating force transmitted via the transmission mechanism is directly applied to the pivot on which the speed change operation link is pivotally connected, and swings the pivot together with the support member about the central axis, whereby the gear ratio is reduced. Changed to a stage. Further, in a link mechanism for transmitting the operating force to the pivot, the swing range of the pivot can be easily set large and the swing speed can be increased by appropriately setting the length of the link.
[0007]
As a result, according to the first aspect of the invention, the following effects can be obtained. That is, the operating force for continuously changing the rotation speed of the output shaft is transmitted to a pivot provided on the support member and to which the transmission operation link is pivotally connected via a link mechanism pivotally connected to the pivot. Accordingly, the operating force for swinging the pivot is directly applied to the pivot using the pivot for pivotally connecting the speed change operation link, so that there is no need to form a portion for receiving the operating force on the support member itself. Accordingly, the supporting member can be reduced in size and weight, and the transmission can be reduced in size and weight. Moreover, by appropriately setting the length of the link constituting the link mechanism, even when the gear ratio is changed over a wide range, the support member does not become large and the weight increases. The gear ratio can be changed quickly.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
Referring to FIG. 1 which is a left side view of a bicycle equipped with the continuously variable transmission of the present invention, a bicycle B is a downhill bicycle, and has a high-speed corner or a jump section on a forest road or the like where there is a noticeable undulation. It is used in competitions where you compete for time by going down an unpaved course.
[0009]
Body frame R of the bicycle B includes a head pipe 1 steerably supports a front fork 5 of the left and right pair for supporting the front wheel W _F at its lower part, the main from the head pipe 1 a pair of left and right extending rearward obliquely downward The main frame 2 includes a frame 2, a down tube 3 extending obliquely rearward and downward from a front end of each of the main frames 2, and a saddle frame 4 extending from a central portion of each main frame 2 and supporting a saddle 6.
[0010]
The pivot shaft 7 which is mounted to a rear portion of the main frames 2, the rear wheel W _R rotatably front end portion rotatably a pair of left and right swing arms 8 supporting an axle 9 for supporting the at the rear portion Supported. The swing arm 8 is connected to a central portion of the main frame 2 via a suspension 10 so that the swing arm 8 can swing up and down around the pivot shaft 7. Further, between the front wheel W _F and the rear wheel W _R in the longitudinal direction, and between the rear part of the rear and down tube 3 of the main frames 2, the continuously variable transmission T are arranged to be supported in their . The continuously variable transmission T is disposed on the upper side than the lower vicinity of the virtual plane H2 or the virtual plane H2 including the rotation axis of the front wheel W _F rotational axis and the rear wheel W _R, the top of the body frame R The lower tube 3 is disposed above the lowermost end 3 a 1 of the down tube 3. In addition, the lower end of the continuously variable transmission T is covered by the lower end 3a including the lowermost end 3a1 of the down tube 3 located in the vicinity thereof in the vehicle width direction (lateral direction). The position of the rotation axis of the front wheel W _F and the rear wheel W _R are those in a state where the driver does not ride.
[0011]
Referring also to FIG. 2, the main shaft 12 a is disposed at the lower portion of the continuously variable transmission T and housed in the case 11, and is coupled to the left and right ends of the main shaft 12 a protruding outside the case 11. The crankshaft 12 having the paired crank arms 12b constitutes a pedal-type crankshaft because the pedals 13 are rotatably supported on the respective crank arms 12b.
[0012]
The output shaft 16 disposed above the continuously variable transmission T and housed in the case 11 has a right end, which is one end protruding outside the case 11, and is provided at the right end outside the case 11. And a driving sprocket 17, which is a driving-side rotating body, is connected. The one-way clutch 82 to the rear hub 80 of rear wheel W _R and the driving sprocket 17 a chain 19 is an endless transmission belt between the driven sprocket 18 is driven-side rotating member which is drivingly connected via a (see FIG. 10) Be passed over. The output shaft 16 is disposed with respect to the vehicle body frame R such that the output shaft 16 is located near an imaginary plane H1 including the respective central axes of the pivot shaft 7 and the axle 9. Further, the driving sprocket 17 is arranged above the virtual plane H2 or near the lower part of the virtual plane H2, and is arranged above the lowermost end 3a1 of the down tube 3. Here, “above the vicinity below the virtual plane H2” means, for example, in the up-down direction, above the position of the lower end of the driven sprocket 18.
[0013]
Therefore, the torque of the crankshaft 12 that is rotationally driven by the driver passes through the output shaft 16 of the continuously variable transmission T, and is transmitted to the output shaft 16 via the transmission mechanism including the driving sprocket 17, the driven sprocket 18, and the chain 19. it is transmitted to the wheels W _R after a drive connected to drive wheels and the rear wheel W _R is rotatably driven.
[0014]
The continuously variable transmission T will be described with reference to FIGS. A case 11 composed of a pair of left and right case portions 11a and 11b joined by bolts is provided with a portion near both ends of a main shaft 12a housed in the case 11, both ends of an idle shaft 14, and a left end of an output shaft 16. The part and the part near the right end are rotatably supported via a pair of left and right bearings 20a, 20b; 20c, 20d; 20e, 20f held by the two case parts 11a, 11b, respectively. In the case 11, the first drive gear 22 and the second driven gear 24 are sequentially provided on the main shaft 12a from the right bearing 20b side, which is one of the bearings. The first drive gear 22 is a forward rotation direction A0 of the crankshaft 12 (a direction in which the bicycle B moves forward. Hereinafter, the forward rotation directions of various shafts and sprockets when the crankshaft 12 rotates forward are denoted by A0. ) Is driven and connected to the main shaft 12a via a one-way clutch 28 that transmits only the torque of the first driven gear 22 to the first drive gear 22, and the second driven gear 24 is rotatably supported by the main shaft 12a via a bearing 29.
[0015]
A first driven gear 23 meshing with the first driving gear 22 and a second driving gear 25 meshing with the second driven gear 24 are provided on the idle shaft 14 arranged parallel to the main shaft 12 a in the case 11. . A third drive gear 26 is provided on the second driven gear 24 so as to be integrally fixed adjacent to the second driven gear 24, and the third drive gear 26 is provided at both ends of the case portions 11a and 11b with bearings 30a at both ends. , 30b is splined to the rotatably supported input shaft 15 and meshes with a third driven gear 27 which rotates integrally with the input shaft 15.
[0016]
Each of the drive gears 22, 25, 26 has a larger diameter than the driven gears 23, 24, 27 meshing therewith, and the drive gears 22, 25, 26 and the driven gears 23, 24, 27 mesh with each other. Thus, a speed increasing gear train having three speed increasing stages and increasing the rotation speed of the crankshaft 12 and transmitting the rotation speed to the input shaft 15 is configured. Therefore, the input shaft 15 that is rotationally driven by the crankshaft 12 via the speed increasing mechanism M1 including the speed increasing gear train disposed in the case 11 rotates the rotation speed of the input shaft 15 higher than the rotation speed of the crankshaft 12. It rotates at a speed, in this embodiment, about 11 times the rotation speed.
[0017]
As shown in FIG. 4, the third drive gear 26 and the third driven gear 27 are formed of non-circular gears, mesh with the timing to reduce the pulsation of the rotation speed of the output shaft 16, and are not connected to the input shaft 15. A non-constant speed rotation transmission mechanism M2 for performing a constant speed rotation motion is configured. Specifically, the third driven gear 27 has the same number of peak portions 27a and valley portions 27b as the number of link units U1 to U4 described later provided in the continuously variable transmission T in this embodiment. The third driving gear 26 has an integral multiple of the number of the peaks 27a and the valleys 27b of the third driven gear 27, that is, four times in this embodiment. The gear has sixteen peaks 26a and valleys 26b. Then, the timing at which the trough 26b of the third drive gear 26 meshes with the peak 27a of the third driven gear 27, and the peak 26a of the third drive gear 26 meshes with the trough 27b of the third driven gear 27. The timing is set so as to match the timing at which the rotational speed of the pulsating output shaft 16 is maximized and the timing at which the rotational speed is minimized, as described later. Therefore, the crankshaft 12 and the input shaft 15 are drivingly connected via a non-uniform speed transmission mechanism M2 incorporated in the speed increasing mechanism M1 to reduce the pulsation of the rotation speed of the output shaft 16.
[0018]
Referring to FIGS. 2 and 3, the input shaft 15 has a transmission mechanism M3 having a plurality of, in this embodiment, four link units U1 to U4, for converting the rotational movement of the input shaft 15 into a rocking movement; Drive-coupled to the output shaft 16 via a one-way clutch 36 which is connected to each link unit U1-U4 and converts the swinging motion of the link unit U1-U4 into a rotational motion of the output shaft 16 in the normal rotation direction A0. Is done. The speed change mechanism M3 is operated by a speed change operation mechanism M4 that is operated by the driver operating a speed change lever (not shown) as a speed change operation member. The speed change mechanism M4 outputs an output corresponding to the rotation speed of the crankshaft 12. The gear ratio, which is the ratio of the rotation speed of the shaft 16, is continuously changed.
[0019]
5 and 6, each of the link units U1 to U4 is composed of a plurality of, in this embodiment, three transmission links. Specifically, a drive link 31 eccentrically attached to the input shaft 15, an output link 33 drive-coupled to the output shaft 16 via a one-way clutch 36, and a first pivot constituting a first pivot portion A transmission 34 is supported rotatably with respect to the drive link 31 at 34, that is, pivotally mounted, and is rotatably supported, that is, pivoted with respect to the output link 33 at a second pivot 35 constituting a second pivot. A link 32.
[0020]
The drive link 31 includes an annular first coupling portion 31a and a bifurcated second coupling portion 31b connected to the first coupling portion 31a and having a pair of plate portions 31b1. The transmission link 32 has one end. The output link 33 is composed of a pair of plates 32c connected at predetermined intervals by rivets 37 at the portion 32a, and the output link 33 is disposed between the two plates 32c of the transmission link 32. And an annular second coupling portion 33b connected to the first coupling portion 33a.
[0021]
The drive link 31 is connected to the input shaft 15 by the first coupling portion 31a being pivotally supported on the outer periphery of an eccentric ring 38 that rotates integrally with the input shaft 15 by spline coupling via a bearing including a slide bearing 39. It is eccentrically pivoted. The central axis of the eccentric ring 38, that is, the rotation axis of the drive link 31 is eccentric with respect to the rotation axis of the input shaft 15 by a predetermined eccentric amount. Further, as shown in FIGS. 5 and 6, a plurality of, for example, four oil grooves 31c are formed in the first coupling portion 31a at equal intervals in the circumferential direction so as to extend in the radial direction. Lubricating oil is supplied to the slide bearing 39 through the oil groove 31c.
[0022]
The transmission link 32 is rotatable on the first pivot 34 fixed and supported by the two plate portions 31b1 of the second coupling portion 31b via a bearing including the needle bearing 40 disposed between the two plate portions 31b1. Supported by The needle bearing 40 is fitted on the outer periphery of the first pivot shaft 34 and is fixed by being pressed and fixed between the two plate portions 31b1. The needle bearing 40 is disposed radially outward of the inner ring 40a and has one end 32a of both plates 32c. The outer ring 40b fits into the hole formed in the inner ring 40a, and a number of needles 40c arranged between the inner ring 40a and the outer ring 40b. The movement of the needle 40c in the axial direction is prevented by the two plate portions 31b1 of the drive link 31 via a pair of thrust washers 43 disposed at both ends of the needle bearing 40. Further, since a large number of needles 40c are arranged without a gap in the circumferential direction, a retainer for holding the needles 40c is unnecessary. Therefore, the needle bearing 40 is a retainerless needle bearing having no retainer. Further, a plurality of oil holes 40d are formed in the outer ring 40b at intervals in the circumferential direction, and in this embodiment, eight oil holes 40d are formed at equal intervals in the circumferential direction.
[0023]
In addition, the first coupling portion 33a of the output link 33 is rotatably supported by the second pivot 35 fixedly supported on the other end 32b of both plates 32c via a bearing including the needle bearing 41. The transmission link 32 is supported by the output link 33 so as to be relatively rotatable. The needle bearing 41 is composed of a large number of needles 41 a that are arranged on the outer periphery of the second pivot 35 and are surrounded and held by the first coupling portion 33 a of the output link 33. Also in this case, the movement of the needle 41a in the axial direction is prevented by the two plates 32c of the transmission link 32 via a pair of thrust washers 44 arranged at both ends of the needle 41a, and the large number of needles 41a are moved in the circumferential direction. They are arranged without gaps. Therefore, the needle bearing 41 is a retainerless needle bearing like the needle bearing 40. As shown in FIG. 6, a plurality of, for example, three oil grooves 33 c are formed at both sides of the first coupling portion 33 a in the circumferential direction at intervals in the circumferential direction so as to extend in the radial direction. Is supplied to the needle bearing 41 through the oil groove 33c.
[0024]
The output link 33 is, in the second coupling portion 33b, a direction in which only the torque for rotating the output shaft 16 in the normal rotation direction A0 from the output link 33 that swings with the rotation axis of the output shaft 16 as the swing axis is transmitted. The drive shaft 16 is drivingly connected to the output shaft 16 via the clutch 36. Therefore, the one-way clutch 36 is actuated when each output link 33 swings in the forward rotation direction A0 at an angular velocity ω (see FIG. 13) of the output shaft 16 in the forward rotation direction A0, that is, at an angular velocity larger than the rotation speed. Only the torque is transmitted from the output link 33 to the output shaft 16. Here, the outer part of the one-way clutch 36 is constituted by the second coupling portion 33b, and the inner part thereof is constituted by the output shaft 16, so that the one-way clutch 36 is drivingly connected to the output link 33 and the output shaft 16. Is done.
[0025]
As shown in FIG. 2, the four link units U <b> 1 to U <b> 4 are arranged at equal intervals with respect to the input shaft 15 and the output shaft 16, which are parallel to each other, in the direction of their rotation axis (also the vehicle width direction). It is arranged in. Specifically, the input shaft 15 is provided with two annular collars 46 as spacers, which are members for maintaining the distance between the adjacent link units U2, U3; U3, U4 in the rotation axis direction. The first coupling portion 31 is fitted on the side of the first coupling portion 31a. The collar 46 is disposed between the adjacent link units U2, U3 and the adjacent link units U3, U4, while increasing the distance between the adjacent link units U1, U2 near the right end, which is one end of the input shaft 15. The third driven gear 27 disposed between the two link units U1 and U2 is used for holding.
[0026]
That is, in the continuously variable transmission T, the idle shaft 14 disposed on the right side, which is one side in the vehicle width direction (corresponding to the left-right direction), which is also the rotation axis direction of the crankshaft 12, The idler shaft 14 to which the first driven gear 23 and the second drive gear 25 constituting the speed increasing mechanism M1 are attached is made as short as possible in the vehicle width direction, and the second driven gear 24 to be attached to the main shaft 12a. In order to reduce the weight and size of the third drive gear 26, the third driven gear 27 that meshes with the third drive gear 26 is the rightmost one that is the specific link unit closest to the bearing 30b that rotatably supports the input shaft 15. The input shaft 15 is coupled between the link unit U1 and the link unit U2 adjacent thereto.
[0027]
Further, referring to FIGS. 2 and 3, the drive link 31 of the right end link unit U1 is disposed between the first drive gear 22 and the third drive gear 26 in the vehicle width direction, and furthermore, due to the reciprocation thereof, The first drive gear 22 and the third drive gear 26 are arranged at positions that can overlap with the first drive gear 22 and the third drive gear 26 in the radial direction of the main shaft 12a.
[0028]
On the other hand, the output shaft 16 is provided with three annular collars as spacers which are members for maintaining the intervals between the adjacent link units U1, U2; U2, U3; U3, U4. It is fitted on the side of 33b.
[0029]
As shown in FIG. 7, the drive links 31 of the four link units U1 to U4 are pivotally connected to the input shaft 15 with different phases. In this embodiment, the rotation axes of all the drive links 31 are rotated. Are pivotally connected to the input shaft 15 so as to be distributed at an equal angle of 90 ° in the circumferential direction of the input shaft 15. FIG. 7 shows the third pivot 53, the support shaft 59, the fourth pivot 61, and the second intermediate link 62 when a later-described transmission operation link 54 occupies the minimum speed ratio position.
[0030]
As shown in FIG. 2, in each of the link units U <b> 1 to U <b> 4, both ends of the eccentric ring 38 and the slide bearing 39 in the axial direction are formed of a pair of disc-shaped members spline-coupled to the input shaft 15. Covered by a cover plate 49. The cover plate 49 is prevented from moving in the axial direction on the input shaft 15 by the collars 46 and 48 and the third driven gear 27.
[0031]
Referring to FIGS. 2, 3, and 8, the speed change operation mechanism M4 is located at a position near the first pivot 34 (in FIG. 3, a later-described central axis 52 is indicated by a two-dot chain line). A supporting member 51 rotatably supported by the case portions 11a and 11b via a bearing 50; and a third pivot that is pivotally attached to each of the link units U1 to U4 by the first pivot 34 and that constitutes a third pivot portion. A speed change operation link 54 pivotally connected to the support member 51 at 53, and an operation shaft 57 that rotates integrally with a drum 56 on which an end of an operation wire 55 connected to the speed change lever (not shown) is locked. A support shaft 59 that is drivingly connected to the operation shaft 57 via a protrusion 58e3 described later; a first intermediate link 60 that rotates integrally with the support shaft 59; and a third pivot 53 that pivotally attaches to the support member 51. And a first intermediate portion formed by a fourth pivot 61 constituting a fourth pivot portion. And a second intermediate link 62 which is pivotally connected to link 60. Here, the first intermediate link 60 and the second intermediate link 62 constitute a link mechanism.
[0032]
Referring to FIG. 2, FIG. 3, FIG. 5, and FIG. 6, the four speed change operation links 54 constituting the speed change operation link row are respectively provided at one end of an annular distal end portion 54a of the needle bearing 40. By being rotatably supported via a bearing composed of a needle bearing 63 disposed between the two plates 32c of the transmission link 32 on the outer periphery, the first pivots 34 of the link units U1 to U4 It is pivotally connected to the drive link 31 and the transmission link 32. The needle bearing 63 is composed of a number of needles 63a that are arranged on the outer periphery of the outer ring 40b and are surrounded and held by the distal end 54a. Therefore, between the two plate portions 31b1 of the drive link 31 in the vehicle width direction, the two-stage needle bearings 40 and 63 which are stacked radially with respect to the first pivot 34 and provided coaxially are arranged. Is done. Further, the movement of the needle 63a in the axial direction is prevented by the two plates 32c of the transmission link 32 via a pair of thrust washers 64 disposed at both ends of the needle 63a, and a large number of needles 40c Placed without. Therefore, the needle bearing 63 is a retainerless needle bearing like the needle bearing 40.
[0033]
As shown in FIGS. 5 and 6, a plurality of oil grooves 54c are provided on both side surfaces of the distal end portion 54a at equal intervals in the circumferential direction, respectively, in this embodiment. Then, the lubricating oil filled in the case 11 is supplied to the needle bearing 63 through the oil groove 54c, and further supplied to the needle bearing 40 through the oil hole 40d of the outer ring 40b. As shown in FIG. 3, a breather pipe 65 and a drain bolt 66 for discharging the lubricating oil in the case 11 are provided in the right case portion 11b.
[0034]
Referring to FIG. 2, FIG. 3, and FIG. 8, the support member 51 includes a support link 51a made of a plate material bent and formed in a U-shape, and is fitted to both ends of the support link 51a to extend in the vehicle width direction. And a connection shaft 51b as a spacer, which is a member for maintaining the distance between the two. The support link 51a includes a pair of parallel side portions 51a1 facing each other in the vehicle width direction, and a connecting portion 51a2 connected to both side portions 51a1. A center shaft 52 supported by bearings 50 held by the case portions 11a and 11b is fixed to each side portion 51a1, so that the support member 51 sandwiches all the link units U1 to U4 in the vehicle width direction. The case 11 is rotatably supported by the case 11 together with the pair of center shafts 52 arranged as described above. Therefore, the support member 51 can swing about the central axis 52. Further, the right side portion 51a1, which is one side portion of the support link 51a, comes into contact with first and second stoppers 67, 68 (see FIG. 3) formed to protrude from the inner surface of the right case portion 11b. A pair of contact surfaces 51a3, 51a4 are respectively formed. The first and second stoppers 67 and 68 define a minimum speed ratio position and a maximum speed ratio position of the speed change operation link 54, respectively.
[0035]
Referring to FIG. 8, a third pivot 53 is fixedly supported on both sides 51 a 1 of the support member 51 over the both sides 51 a 1 in the vicinity of the connection part 51 a 2. The four speed change operation links 54 pivotally connected to the four link units U1 to U4 at the distal end 54a respectively have a bearing 69 having a large number of needles 69a at an annular base end 54b at the other end. Pivotally connected to the support member 51 by a third pivot 53 via a bearing composed of On both side surfaces of the base end portion 54b, a plurality of oil grooves 54c are provided at intervals in the circumferential direction, and in this embodiment, four oil grooves 54c are provided at equal intervals in the circumferential direction. Then, the lubricating oil filled in the case 11 is supplied to the needle bearing 69 through the oil groove 54c.
[0036]
Further, the speed change operation links 54 are arranged at equal intervals in the axial direction (vehicle width direction) on the third pivot 53, and a collar 70 and a second intermediate link 62 are used for that purpose. That is, the collar 70 as a spacer is disposed between the transmission operation links 54 adjacent to each other at the center (the transmission operation links 54 are pivotally connected to the link units U2 and U3). A second intermediate bifurcated branch is provided between the transmission operation link 54 at both ends (the transmission operation link 54 is pivotally connected to the link units U1 and U4, respectively) and the transmission operation link 54 adjacent thereto. Both ends 62 a of the link 62 are pivotally attached to the third pivot 53 via bearings composed of a slide bearing 71, respectively. Therefore, both end portions 62 a arranged between both side portions 51 a 1 of the support member 51 are used as spacers having the same function as the collar 70.
[0037]
Referring to FIGS. 8 and 9, a support shaft 59 rotatably supported by the left case portion 11a via a bearing 72 is driven by the input shaft 15 acting on the drive link 31 of each of the link units U1 to U4. The component of the force (see FIG. 14) rotates the drum 56 through the first pivot 34, the speed change operation link 54, the support member 51, the third pivot 53, the second intermediate link 62, the first intermediate link 60, and the support shaft 59. It is held on the right case part 11b via a two-way clutch 58 having the function of two one-way clutches for preventing movement.
[0038]
The two-way clutch 58 includes an outer race 58a fixed to the right case portion 11b, and a member that rotates integrally with the support shaft 59. In this embodiment, the two-way clutch 58 includes an inner race 58b formed from a part of the support shaft 59. An even number arranged in the accommodation space between the races 58a and 58b in the radial direction, in this embodiment, eight rollers 58c and a pair of rollers 58c arranged in the accommodation space in the circumferential direction. The clutch spring 58d includes a compression spring, and a retainer 58e disposed between the two rollers 58c in the circumferential direction on the opposite side of the clutch spring 58d.
[0039]
A retainer 58e integrally formed with the operation shaft 57 has a rotation direction A2 (hereinafter referred to as an up direction A2) for shifting up the operation shaft 57 and a rotation direction A3 (hereinafter referred to as down direction) for shifting down. When it rotates in the direction A3), it comes into contact with the roller 58c. More specifically, the retainer 58e has a pair of engagement portions each having a projection 58e3 that is engageable with an engagement portion formed of a recess 58b1 formed in the inner race 58b so as to oppose the operation shaft 57 in the diametric direction. The first holding portion 58e1 and the second holding portion 58e2 located between the first holding portions 58e1 in the circumferential direction.
[0040]
A gap 58f is formed between the recess 58b1 and the projection 58e3 to enable the relative rotation between the retainer 58e and the inner race 58b. Then, by this relative rotation until the recess 58b1 and the protrusion 58e3 engage, the first and second holding portions 58e1 and 58e2 press the roller 58c against the elastic force of the clutch spring 58d. , The roller 58c does not bite (ie, lock) between the outer race 58a and the inner race 58b, that is, the unlocked state.
[0041]
On the outer periphery of the inner race 58b, of the pair of rollers 58c opposed to each other via the clutch spring 58d, the roller 58c1 on the up direction A2 side allows the rotation of the support shaft 59 in the up direction A2. On the other hand, the rotation of the support shaft 59 in the down direction A3 is prevented, and the roller 58c2 on the down direction A3 side allows the rotation of the support shaft 59 in the down direction A3, while supporting the support shaft 59 in the up direction A2. A cam surface 58b2 is formed so that the width of the housing space in the radial direction is different in the circumferential direction so as to prevent the rotation of the shaft 59.
[0042]
Therefore, when the operation force applied to the shift lever causes the drum 56 to rotate in the up direction A2 via the operation wire 55, as shown by a two-dot chain line in FIG. After the rollers 58e1 and 58e2 relatively rotate in the up direction A2 and come into contact with the rollers 58c2 to bring the rollers 58c2 into the unlocked state, the projection 58e3 and the recess 58b1 are engaged with each other, whereby the first holding portion 58e1 is It engages with the inner race 58b and rotates together with the support shaft 59 in the up direction A2. Conversely, when the operating force causes the drum 56 to rotate in the down direction A3 via the operation wire 55, the first and second holding portions 58e1 and 58e2 relatively rotate in the down direction A3 and come into contact with the roller 58c1. After the roller 58c1 is in the unlocked state, the projection 58e3 and the recess 58b1 engage with each other, so that the first holding portion 58e1 engages with the inner race 58b, and together with the support shaft 59 in the down direction A3. Rotate.
[0043]
By the way, referring to FIG. 12, during rotation of the crankshaft 12, torque is transmitted to the output shaft 16 via the output link 33 and the one-way clutch 36, and the link units U1 to U4 rotate the output shaft 16. As for the driving force from the input shaft 15 for reciprocating the driving links 31 of the link units U1 to U4, one component force acts on the output link 33 from the first pivot 34 via the transmission link 32. On the other hand, the other component force F acts on the speed change operation link 54 from the first pivot 34. The component force F generates a moment about a center axis 52 located substantially at the center of the movement path of the first pivot shaft 34 that reciprocates due to the rotation of the input shaft 15 when viewed from the rotation axis direction of the input shaft 15. . (Here, the central axis 52, the first to third pivots 34, 35, 53, and the input shaft 15 are arranged in parallel with each other.) This moment depends on the position of the first pivot 34 and the central axis 52. , Ie, a moment m that causes the third pivot to swing clockwise and a moment m that causes the third pivot to swing counterclockwise. Then, this moment generates a torque Ta (see FIG. 3) for rotating the support shaft 59 in the up direction A2 or the down direction A3 via the second intermediate link 62 and the first intermediate link 60. As shown in FIG. 14, the torque Ta has a magnitude and a direction corresponding to a change in the driving force acting on the drive link 31 of the link units U1 to U4 that are driving the output shaft 16 to rotate. In FIG. 14, reference numeral U1~U4 indicates a link unit that rotates the output shaft 16, reference numeral T ₀ indicates a value to indicate the magnitude measure of the torque Ta. At this time, if the operation force is not acting on the retainer 58e through the operation wire 55, the roller 58c is locked even if the torque Ta tries to rotate the support shaft 59 in either the up direction A2 or the down direction A3. , The support shaft 59 does not rotate. Further, when an operating force for shifting up (shifting down; hereinafter, a description corresponding to shifting down is given in parentheses) is acting on the retainer 58e, the torque Ta causes the support shaft 59 to move the support shaft 59 in the up direction A2. When acting so as to rotate in the (down direction A3), the torque Ta becomes an assist force, and the operating force is reduced, while the torque Ta rotates the support shaft 59 in the down direction A3 (up direction A2). In such a case, the roller 58c is locked, and the support shaft 59 is prevented from rotating in the down direction A3 (up direction A2).
[0044]
Therefore, the operating shaft 57, the two-way clutch 58, the support shaft 59, the first intermediate link 60, the fourth pivot 61, and the second intermediate link 62 transmit the operating force of the operation lever to the third pivot 53. Construct M5.
[0045]
10 and 11, a description will be given in relation to the rear hub 80 and the driven sprocket 18. A driven sprocket 18 is provided via a one-way clutch 82 on the right end, which is one end of a rear hub 80 rotatably supported on the axle 9 via a bearing 81, via a one-way clutch 82. The right end, which is one end of the one-way clutch 82, is covered by a cover 83 provided between the driven sprocket 18 and the axle 9.
[0046]
One-way clutch 82 for transmitting to the rear wheel W _R torque for rotating the rear wheel W _R in the normal direction A0 from the chain 19, and the outer race 82a constituted by the driven sprocket 18 which is drivingly connected to the chain 19, rear hub and the inner race 82b that rotates integrally with the rear wheel W _R is screwed to 80, the races 82a, a plurality of which are spaced circumferentially housing space S between the radial direction 82b, the In the embodiment, ten rollers 82c, a retainer 82d for keeping a circumferential interval between the rollers 82c adjacent in the circumferential direction, and a clutch spring 82e composed of a compression spring disposed between the outer race 82a and the retainer 82d. Consists of
[0047]
The retainer 82d is located between annular large-diameter rings 82d1 and small-diameter rings 82d2 that are spaced apart in the vehicle width direction, and rollers 82c that are connected to the two rings 82d1 and 82d2 and extend in the vehicle width direction and are adjacent in the circumferential direction. more, and 10 of the holding portion 82D3 in this embodiment, through a long hole 18a formed on the driven sprocket 18 is integrally formed on the holding portion 82D3 ₁ pair in a position diametrically opposed to the right And a positioning portion composed of a projection 82d4 that protrudes. The cover 83 and the retainer 82d are integrally rotatable by engaging the projection 82d4 with the engaging portion formed of the concave portion 83a formed on the cover 83.
[0048]
Here, each roller 82c bites (that is, locks) between the cam surface 82a1 formed on the inner peripheral surface of the outer race 82a and the inner race 82b, and rotates the outer race 82a and the inner race 82b integrally. The outer race 82a and the inner race 82b are independently rotatably maintained without biting between the cam surface 82a1 and the inner race 82b in a state (ie, a locked state, which is indicated by a two-dot chain line in FIG. 11). (I.e., unlocked state). The long hole 18a has a shape that forms a circumferential gap between the outer race 82a and the projection 82d4 so that the outer race 82a can rotate relative to the retainer 82 by a predetermined angle θ3 described later.
[0049]
Clutch spring 82e is disposed between the pair of holding portions 82D3 and the outer race 82a in a position diametrically opposed, the holding portion 82D3 ₂ of the pair abuts the outer race 82a by the elastic force In the normal direction A0. Specifically, the recess 82f of the pair on the inner peripheral surface of the outer race 82a in a position facing a pair of holding portions 82D3 ₂ in the radial direction is formed, on the outer circumferential surface of the holding portion 82D3 ₂ respectively in the recess 82f A projecting portion n is formed to enter. The clutch spring 82e is disposed in the concave portion 82f, contacts the outer race 82a at the end opposite to the normal rotation direction A0, and contacts the protrusion n at the end at the normal rotation direction A0. The projecting portion n is urged in the forward rotation direction A0 by the elastic force to abut the outer race 82a.
[0050]
The clutch springs 82e for applying a resilient force between the outer race 82a and the holding portion 82d3 _2, the outer race 82a and the retainer 82d, except during the rotation of the forward direction A0 of the outer race 82a, protrusion n is positive The roller 82c abuts on the outer race 82a on the rolling direction A0 side and occupies the first rotation position where the lock state is released (shown by a solid line in FIG. 11).
[0051]
The cover 83 that covers the opening of the one-way clutch 82 to prevent the lubricant from leaking from the storage space S and prevent foreign matter such as water and dust from entering the storage space S is provided inside the cover 83. By being fixed to the barrel 84 fixed to the axle 9, the ring-shaped friction spring 85 made of a wire fixed to the axle 9 urges it radially outwardly. In this state, it is slidably in contact. In the one-way clutch 82, a seal 86 is provided between the outer periphery of the cover 83 and the outer race 82a, and a seal 87 is provided between the inner periphery of the cover 83 and the shaft cylinder 84 on the opposite side of the cover 83 from the inner side. The seal 88 seals between the race 82b and the outer race 82a.
[0052]
The set load of the friction spring 85 allows the outer race 82a to elastically deform the clutch spring 82e immediately after the start of rotation in the normal rotation direction A0, thereby allowing the outer race 82a to rotate the retainer 82d by the predetermined angle θ3 in the normal rotation direction A0 with respect to the retainer 82d. When the roller 82c is locked and the one-way clutch 82 is connected, the cover 83 is integrally formed with the retainer 82d, the outer race 82a (the driven sprocket 18), and the inner race 82b. The size is set so that it can be rotated.
[0053]
Due to the frictional force between the cover 83 and the friction spring 85, immediately after the outer race 82a starts rotating in the normal rotation direction A0, the one-way clutch 82 in which the roller 82c is in the unlocked state and is in the disconnected state is connected. When shifting to the state, since the relative rotation does not occur between the axle 9 and the retainer 82d, the clutch spring 82e is compressed by the driven sprocket 18 (outer race 82a) that normally rotates against its resilient force, The outer race 82a and the retainer 82d occupy a second rotation position in which the outer race 82a has rotated by a predetermined angle θ3 with respect to the retainer 82d, and the retainer 82d is held so that the roller 82c is locked. . When the one-way clutch 82 is engaged, the retainer 82d and the outer race 82a (the driven sprocket 18) rotate together with the cover 83 and the inner race 82b while maintaining the second rotational position. Therefore, immediately after the driven sprocket 18 starts rotating in the normal rotation direction A0, the friction spring 85 and the cover 83 allow the retainer 82d to rotate the retainer 82d by the predetermined angle θ3 in the normal rotation direction with respect to the retainer 82d. Is constituted.
[0054]
When the driven sprocket 18 rotates in the normal rotation direction A0 by such a one-way clutch 82, the roller 82c is locked, and the driven sprocket 18 and the rear hub 80 rotate integrally. Further, when the driver stops pedaling while riding the bicycle B or when the bicycle B is moved forward with the driver getting off, the elasticity of the clutch spring 82e causes the chain 19 to move forward. The driven sprocket 18 is rotated in the direction opposite to the normal rotation direction A0 by the slack, the roller 82c is unlocked, the one-way clutch 82 is disconnected, and the driven sprocket 18 is stopped. wheel _{W R} only, i.e. only the rear hub 80 is rotated in the normal direction A0. Further, for example, when the bicycle B is moved backward with the driver getting off the vehicle, the roller 82c is in the unlocked state shown in FIG. 11 due to the elastic force of the clutch spring 85, and the one-way clutch 82 is in the disengaged state. Therefore, with the driven sprocket 18 stopped, only the rear wheel W _R , that is, only the rear hub 80 rotates in the reverse direction.
[0055]
Next, the operation of the continuously variable transmission T will be described. As shown in FIG. 3, when the bicycle B is running with the continuously variable transmission T at the minimum speed ratio, the position of the third pivot 53 with the support member 51 in contact with the first stopper 67. Has been fixed. At this time, while the input shaft 15 makes one rotation, as shown in FIG. 12A, the drive link 31 rotates the drive link 31 per one rotation of the input shaft 15 by the driving force from the input shaft 15. The link units U1 to U4 reciprocate between P1 and P2, and sequentially swing the output link 33 within the swing angle range θ1. Since the link units U1 to U4 are drivingly connected to the output shaft 16 via the one-way clutch 36, in the continuously variable transmission T having four link units U1 to U4, one rotation of the input shaft 15 is performed. 13A, the output shaft 16 rotationally drives the output shaft 16 at the maximum angular velocity (rotational speed) in the normal rotation direction A0 among the four link units U1 to U4, as shown in FIG. The link units U1 to U4 are sequentially driven to rotate.
[0056]
At this time, at the timing when the rotation speed of the output shaft 16 is maximized, the rotation speed of the input shaft 15 is reduced by the unequal speed rotation transmission mechanism M2 using the non-circular gear including the third drive gear 26 and the third driven gear 27. The timing becomes the minimum, for example, the timing when the link unit U1 drives the output shaft 16 to the state where the link unit U2 having a phase of 90 ° with respect to the link unit U1 drives the output shaft 16, that is, the output shaft At the timing when the rotation speed of the output shaft 16 is minimum, the rotation speed of the input shaft 15 is maximized by the unequal-speed rotation transmission mechanism M2, the fluctuation width of the rotation speed of the output shaft 16 is reduced, and the pulsation is reduced. Is done. In FIG. 13, reference numerals U <b> 1 to U <b> 4 indicate a link unit that rotationally drives the output shaft 16, and reference numeral ω <b> ₀ indicates a value indicating a measure of the angular velocity ω of the output shaft 16.
[0057]
When the driver operates the shift lever to shift up from the operating state at the minimum gear ratio, the operating force is applied to the two-way clutch 58 via the operating wire 55, the drum 56, and the operating shaft 57 (see FIG. 9). Is rotated in the up direction A2. At this time, as shown in FIG. 14A, the drive force is generated based on a component F of the drive force in the direction in which the output shaft 16 is accelerated by the drive force from the input shaft 15 to each of the link units U1 to U4. The torque Ta (the torque on the positive side in FIG. 14) acts on the support shaft 59 via the speed change operation link 54, the second intermediate link 62, and the first intermediate link 60 as an assist force. Then, the rotation of the support shaft 59 causes the third pivot shaft 53 and the base end portion 54b of the speed change operation link 54 to move on an arc-shaped speed change trajectory centered on the central shaft 52 supporting the support member 51 as shown in FIG. move toward the position of the maximum speed ratio represented, the rear wheel W _R is rotated at a greater speed ratio.
[0058]
Referring to FIG. 12B, in a state where the speed change operation link 54 and the third pivot 53 are at the maximum speed ratio (see FIG. 15), while the input shaft 15 makes one rotation, each rotation of the input shaft 15 The drive link 31 reciprocates between the illustrated positions P3 and P4, and each of the link units U1 to U4 connects the output link 33 with a swing angle range θ2 larger than the swing angle range θ1 at the minimum speed ratio. Rock it. Then, during one rotation of the input shaft 15 by the four link units U1 to U4, as shown in FIG. 13B, the output shaft 16 has the maximum angular velocity (rotational speed) in the normal rotation direction A0. The output shaft 16 is sequentially rotated and driven by link units U1 to U4 which rotationally drive. Also at this time, similarly to the case of the above-described minimum speed ratio, the fluctuation width of the rotation speed of the output shaft 16 is reduced by the unequal-speed rotation transmission mechanism M2, and the pulsation is reduced.
[0059]
When the driver operates the operation lever to shift down from the operation state at the maximum gear ratio, the operation force is applied to the two-way clutch 58 (FIG. 9) via the operation wire 55, the drum 56, and the operation shaft 57. Is rotated in the down direction A3. At this time, as shown in FIG. 14 (B), it is generated based on the component F of the driving force in the direction in which the output shaft 16 is decelerated by the driving force from the input shaft 15 to each of the link units U1 to U4. The torque Ta (minus side torque in FIG. 14) acts on the support shaft 59 as an assist force. Then, by the rotation of the support shaft 59, the third pivot shaft 53 and the base end portion 54b move on the speed change trajectory from the position at the maximum speed ratio to the position at the minimum speed ratio, and a smaller speed change is performed. the rear wheel W _R is rotationally driven at a ratio.
[0060]
In this way, the third pivot 53, which can swing around the central shaft 52 by the speed change operation by the speed change operation mechanism M4, can be moved to any position between the position at the minimum speed ratio and the position at the maximum speed ratio. it is possible to occupy position steplessly, the rotational speed of the crankshaft 12 is transmitted to the rear wheel W _R is steplessly.
[0061]
Next, the operation and effect of the embodiment configured as described above will be described.
The operation force for continuously changing the rotation speed of the output shaft 16 is applied to a pivot 53 provided on the support member 51 and to which a speed change operation link 54 is pivotally attached, by the link mechanism pivotally attached to the pivot 53. By being transmitted via the second intermediate link 62, the operating force for swinging the pivot 53 is applied directly to the pivot 53 using the pivot 53 for pivotally connecting the speed change operation link 54, and the central shaft 53 Since the pivot 53 is pivoted together with the support member 51 about the center 52, there is no need to form a portion for receiving an operation force on the support member 51 itself, so that the support member 51 can be reduced in size and weight, and the continuously variable transmission T Can be reduced in size and weight. In addition, by appropriately setting the lengths of the first and second intermediate links 60 and 62 constituting the link mechanism, even when the speed ratio is changed over a wide range, the size of the support member 51 can be increased and the size can be increased. In addition to increasing the weight, the swing range of the pivot 53 can be easily set large, the swing speed can be increased, and the gear ratio can be changed quickly.
[0062]
The continuously variable transmission T is between the front wheel W _F and the rear wheel W _R, above the lower vicinity of the virtual plane H2 or the virtual plane H2 containing respective axes of rotation of the front wheel W _F and the rear wheel W _R By arranging, compared to the prior art, it is arranged at a position near the center of gravity of the vehicle body and at a position away from the ground, so that the operability of the bicycle B is improved and the continuously variable transmission is provided. T has little contact with the ground. Further, the drive link 31 of each of the link units U1 to U4 is pivotally supported by the eccentric ring 38 connected to the input shaft 15, so that the swing range of the drive link 31 can be changed depending on the model or by changing the specification. When the gear ratio range is changed by changing the gear ratio, the swing range of the drive link 31 can be changed by replacing the eccentric ring 38, and the gear ratio range can be easily changed. Since the input shaft 15 can be used as a common component, the cost of the continuously variable transmission T can be reduced.
[0063]
The drive sprocket 17 and the continuously variable transmission T, which are coupled to the end of the output shaft 16 outside the case 11 of the continuously variable transmission T, are disposed above the lowermost end 3a1 of the down tube 3, so that Since the drive sprocket 17 and the continuously variable transmission T located outside the stepped transmission T can be prevented from coming into contact with the ground by the lowermost end 3a1 of the down tube 3 located below, the continuously variable transmission T can be prevented. T and the contact of the drive sprocket 17 with the ground can be further avoided.
[0064]
The speed increasing gear train provided on the crankshaft 12 and the idle shaft 14 for increasing the rotation speed of the crankshaft 12 and transmitting the rotation speed to the input shaft 15 is arranged in the case 11 of the continuously variable transmission T. A speed increasing mechanism M1 for increasing the rotation speed of the crankshaft 12 and transmitting the rotation speed to the input shaft 15 is provided in the case 11 of the continuously variable transmission T by using the crankshaft 12 and the idle shaft 14. Since the speed increasing mechanism M1 is used, the speed increasing mechanism M1 can be made compact, and the degree of freedom of arrangement with respect to the vehicle body frame R, and hence the degree of freedom of arrangement of the continuously variable transmission T with respect to the body frame R, is increased. Become.
[0065]
In addition, since the input shaft 15 and the output shaft 16 are drivingly connected via the link units U1 to U4 composed of a plurality of links, the degree of freedom of the arrangement of the output shaft 16 with respect to the crankshaft 12, and eventually the body frame R is increased. growing. Therefore, when the rear wheel W _R is supported by the swingable swing arm 8 in the vertical direction, it is arranged the output shaft 16 in the vicinity of the virtual plane H1 containing the pivot shaft 7 relative to the vehicle body frame R it can.
[0066]
Since the speed increasing mechanism M1 provided between the crankshaft 12 and the input shaft 15 includes the unequal-speed rotation transmitting mechanism M2, the pulsation of the rotation speed of the output shaft 16 is reduced, and a comfortable traveling property is obtained. be able to. In addition, since the speed increasing mechanism M1 is used to reduce the pulsation, the weight of the continuously variable transmission T is prevented from increasing, and the input shaft 15 becomes longer in the direction of its rotation axis to reduce the pulsation. In addition, the size of the continuously variable transmission T in the rotation axis direction is prevented.
[0067]
Since the unequal-speed rotation transmission mechanism M2 is composed of a speed increasing gear train having a driving gear 26 and a driven gear 27 formed of a pair of non-circular gears, the pulsation of the rotation speed of the output shaft 16 can be reduced with a simple configuration. You. The driven gear 27 is connected to the input shaft 15 between the link unit U1 closest to the bearing 30b that rotatably supports the input shaft 15 and the link unit U2 adjacent to the link unit U1, and the driven gear 27 is connected to the link unit U1. Since the driven gear 27 also serves as a spacer for arranging the link units U1 and U2 on the input shaft 15 by maintaining the distance between the U1 and U2 in the direction of the rotation axis, the spacer can be reduced and the stepless transmission can be performed. The weight increase of the device T is prevented, and the bending of the input shaft 15 due to the load applied to the driven gear 27 is reduced even though the final gear of the speed increasing mechanism M1 is one driven gear 27, so that each link unit U1 To U4, the input shaft 15 is prevented from increasing in diameter to increase the rigidity of the input shaft 15, and the weight of the continuously variable transmission T is reduced. There is prevented.
[0068]
The first and second pivots 34 and 35 of the plurality of link units U1 to U4 arranged side by side on the input shaft 15 in the direction of the rotation axis thereof are arranged in parallel with the input shaft 15 and the first and second pivots 34. , 35 are provided with needle bearings 40, 41, 63 having no retainer, and two of the drive link 31, the transmission link 32, the output link 33, and the speed change operation link 54 are connected by the needle bearings 40, 41, 63. Since the links 31, 32, 33, and 54 supported by the needle bearings 40, 41, and 63 are smoothly rotated by being supported so as to be relatively rotatable, the speed change operation is smooth and the needle bearing is further improved. In the first and second pivots 34 and 35 provided with 40, 41 and 63, since there is no retainer, the rotation of the input shaft 15 in the axial direction of the needles 40c, 41a and 63a is possible. It is possible to reduce the width in the axial direction (vehicle width direction), the width in which a plurality of link units U1~U4 occupied by the rotational axis direction is also reduced, thereby downsizing the continuously variable transmission T.
[0069]
In the first pivot 34, two needle bearings 40, 63 having no retainer are laminated in the radial direction and provided coaxially, and the drive link 31, the transmission link 32, and the speed change operation link 54 are supported so as to be rotatable relative to each other. As a result, in the first pivot 34, the two needle bearings 40, 63 do not have a retainer, although two bearings are provided on one pivot and three links are supported. In addition, since the bearings 40 and 63 are stacked in the radial direction, the width of the first pivot 34 on which the drive link 31, the transmission link 32, and the speed change operation link 54 are supported in the rotation axis direction is reduced. Can be.
[0070]
The movement of the needles 40c, 41a, 63a constituting the needle bearings 40, 41, 63 in the axial direction is controlled by the drive links supported by the first and second pivots 34, 35 provided with the needle bearings 40, 41, 63. Since the blockage is prevented by using the transmission link 31 or the transmission link 32, the needles 40c, 41a, and 63a can be surely prevented from coming off without increasing the number of components.
[0071]
A torque generated by a transmission mechanism M5 that transmits an operation force for a speed change operation to the third pivot 53 based on a component F of a driving force for driving the link units U1 to U4 transmitted via the speed change operation link 54. Since Ta is the assisting force of the operating force, the input shaft 15 is rotationally driven by the crankshaft 12, and the driver uses the reciprocating motion of the drive link 31 driven by the driving force, so that the driver can release the pedal 13. The operating force of the shifting operation when the crankshaft 12 is rotated while rowing is reduced, and a light shifting operation can be performed.
[0072]
In addition, the transmission mechanism M5 includes a two-way clutch 58 that prevents the rotation of the support shaft 59 due to the force applied from the speed change mechanism M3 and allows the rotation of the support shaft 59 due to the operation force applied from the operation lever. As a result, the shift operation can be reliably performed not only when the bicycle B is stopped but also when the bicycle B is running.
[0073]
The drive link 31 of the rightmost link unit U1, which is one of the drive links 31 pivotally connected to the input shaft 15, configures a pair of speed increasing stages of the speed increasing mechanism M1 in the vehicle width direction. The first drive gear 22 and the third drive gear 26 are arranged between the first drive gear 22 and the third drive gear 26, and the first drive gear 22 and the third drive gear 26 can be overlapped with the main shaft 12 a of the crankshaft 12 in the radial direction. Accordingly, the continuously variable transmission T can be downsized in the vehicle width direction, and the distance between the crankshaft 12 and the input shaft 15 can be reduced. In this regard, the continuously variable transmission T can be downsized. Can contribute to
[0074]
In order to arrange all the speed change operation links 54 supported on the third pivot 53 at equal intervals in the vehicle width direction, adjacent to the collar 70, a second intermediate link 62 supported on the third pivot 53 is used. By maintaining the interval between the speed change operation links 54, the number of collars as spacers can be reduced, and the width of the support member 51 supporting the third pivot 53 and the input shaft 15 in the vehicle width direction can be reduced. Thus, the size of the support member 51, the input shaft 15, and thus the continuously variable transmission T can be reduced in the vehicle width direction.
[0075]
A clutch spring 82e for applying a resilient force between the outer race 82a and the retainer 82d such that the one-way clutch 82 causes the roller 82c to be in the unlocked state except when the outer race 82a rotates in the normal rotation direction A0; The outer race 82a immediately after the start of the rotation in the normal rotation direction A0 causes the clutch spring 82e to elastically deform to allow the outer race 82a to rotate with respect to the retainer 82d in the normal rotation direction A0 by the predetermined angle θ3, and the roller 82c is locked. And the holding means for holding the retainer 82d so that the one-way clutch 82 is brought into the connected state immediately after the outer race 82a driven by the chain 19 stops rotating at the predetermined angle θ3 in the normal rotation direction A0. The inner race 82b and the retainer 82d It rotates in the normal rotation direction A0 together with the switch 82a. Further, when the driver is backward bicycle B in a state of getting off, but the rear wheel W _R is rotated in the reverse direction, the roller 82c is in the unlocked state by the elastic force of the clutch spring 82e, one since way clutch 82 becomes disconnected state, the rotation of the rear wheel W _R is transmitted to the outer race 82a, the continuously variable transmission T further without being transmitted to the crankshaft 12, the continuously variable transmission T is protected You.
[0076]
The rotation of the reverse rotation direction of the rear wheel W _R without having to transmit to the continuously variable transmission T and the crankshaft 12, the one-way clutch 82 becomes connected state immediately Moreover the rotation of the forward rotation direction A0 of the rear wheel W _R The retainer 82d is configured to have a simple structure by using a cover 83 covering the opening of the one-way clutch 82 and a friction spring 85 and utilizing a frictional force therebetween. Can be.
[0077]
Since the protrusion n of the retainer 82d and the clutch spring 82e are accommodated in the concave portion 82f formed on the inner peripheral surface of the outer race 82a of the one-way clutch 82, the size of the one-way clutch 82 is increased by providing the clutch spring 82e. Is avoided.
[0078]
Hereinafter, an embodiment in which a part of the configuration of the above-described embodiment is changed will be described with respect to the changed configuration.
In the above-described embodiment, the unequal-speed rotation transmission mechanism M2 is formed of a non-circular gear. However, the unequal-speed rotation transmission mechanism M2 may be formed of another member that generates unequal-speed rotation such as an eccentric gear. Good. The speed increasing mechanism M1 may have a plurality of speed increasing steps other than three or one speed increasing step. Furthermore, the bicycle may be a bicycle other than a downhill bicycle, or may be a tricycle. Further, the endless transmission band and the driving-side / driven-side rotator constituting the transmission mechanism may be a belt and a pulley, respectively.
[0079]
In the above embodiment, the support link 51a is constituted by a single member forming the pair of side portions 51a1 and the connecting portion 51a2, but the pair of side portions and the connecting portion are formed as three separate members. May be combined.
[Brief description of the drawings]
FIG. 1 is a left side view of a bicycle equipped with a continuously variable transmission according to an embodiment of the present invention.
FIG. 2 is an exploded cross-sectional view of each link unit that constitutes the transmission mechanism of the continuously variable transmission shown in FIG. 1; for example, as shown by a IIA-IIA line in FIG. FIG. 4 is a sectional view taken along a section passing through an axis and a central axis of a pivot, and a part thereof taken along a line IIB-IIB in FIG. 3.
FIG. 3 is a right side view of the continuously variable transmission shown in FIG. 1 in a state of a minimum speed ratio when a right case portion is removed and various shafts are sectioned;
FIG. 4 is a front view of gears constituting a variable speed rotation transmission mechanism of the continuously variable transmission shown in FIG. 1;
FIG. 5 is a sectional view taken along line VV in FIG. 6;
FIG. 6 is a right side view of a link unit constituting a transmission mechanism of the continuously variable transmission shown in FIG. 1;
FIG. 7 is a schematic diagram illustrating a form of pivotal attachment to an input shaft of four link units constituting a transmission mechanism of the continuously variable transmission shown in FIG. 1;
8 is a sectional view taken along lines VIIIA-VIIIA and VIIIB-VIIIB in FIG. 3;
FIG. 9 is a sectional view taken along line IX-IX in FIG. 8;
10 is a cross-sectional view of the rear hub and the driven sprocket of the bicycle of FIG. 1, taken along the line XX of FIG. 11;
11 is a sectional view taken along line XI-XI in FIG.
12A and 12B are schematic diagrams illustrating a swing angle range of an output link of the continuously variable transmission shown in FIG. 1, wherein FIG. 12A is for a minimum speed ratio, and FIG. 12B is for a maximum speed ratio; It is.
FIGS. 13A and 13B are diagrams illustrating the angular speed of the output shaft of the continuously variable transmission shown in FIG. 1, in which FIG. 13A shows the minimum speed ratio and FIG. 13B shows the maximum speed ratio.
14A and 14B are diagrams illustrating a torque generated based on a component force of a driving force in one rotation of an input shaft of the continuously variable transmission in FIG. 1, wherein FIG. B) is at the maximum speed ratio.
FIG. 15 is a right side view similar to FIG. 3, when the continuously variable transmission is in a state of a minimum gear ratio.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Head pipe, 2 ... Main frame, 3 ... Down tube, 4 ... Saddle frame, 5 ... Front fork, 6 ... Saddle, 7 ... Pivot shaft, 8 ... Swing arm, 9 ... Axle, 10 ... Suspension, 11 ... Case , 12 ... crankshaft, 13 ... pedal, 14 ... idle shaft, 15 ... input shaft, 16 ... output shaft, 17 ... drive sprocket, 18 ... driven sprocket, 19 ... chain, 20a-20f ... bearing, 22-27 ... gear , 28 ... one-way clutch, 29, 30a, 30b ... bearing, 31 ... drive link, 32 ... transmission link, 33 ... output link, 34, 35 ... pivot, 36 ... one-way clutch, 37 ... rivet, 38 ... eccentric ring , 39-41 ... bearing, 43, 44 ... thrust washer, 46-48 ... collar, 49 ... coating plate, 50 ... bearing, 51 ... support , 52 central axis, 53 central axis, 54 speed change operation link, 55 operation wire, 56 drum, 57 operation axis, 58 bidirectional clutch, 59 support axis, 60 intermediate link, 61 axis, 62 ... intermediate link, 63 ... bearing, 64 ... last washer, 65 ... breather tube, 66 ... drain bolt, 67,68 ... stopper, 69 ... bearing, 70 ... collar, 71,72 ... bearing,
80 ... rear hub, 81 ... bearing, 82 ... one-way clutch, 83 ... cover, 84 ... shaft cylinder, 85 ... friction spring, 86, 87, 88 ... seal,
B ... bicycle, R ... body frame, W F _... front wheel, W R _... rear wheel, T ... stepless transmission, H1, H2 ... virtual plane, M1 ... speed increasing mechanism, M2 ... unequal speed rotation transmitting mechanism, M3 ... Transmission mechanism, M4 ... Transmission operation mechanism, M5 ... Transmission mechanism, U1 to U4 ... Link unit, A2, A3 ... Rotating direction, P1 to P4 ... Position, F ... Component force, Ta ... Torque, n ... Protrusion ω: angular velocity.

Claims (1)

A plurality of link units (U1 to U1) each including a plurality of speed change links (31 to 33) for converting a rotational motion of an input shaft (15) rotationally driven by a pedal type crankshaft (12) into a swinging motion. A transmission mechanism (M3) having U4);
A one-way clutch (36) connected to each of the link units (U1 to U4) and converting a swinging motion of the link units (U1 to U4) into a rotational motion of the output shaft (16);
A transmission mechanism (M5) for transmitting an operation force for a speed change operation, and a support in which a pivot (53) is integrally supported and is swingable about a central axis (52) by the transmission mechanism (M5). A transmission operation link (54) pivotally connected at one end to each of the link units (U1 to U4) and at the other end to the pivot (53); Rotation of the output shaft (16) by swinging the pivot (53) together with the support member (51) about the center axis (52) by an operating force transmitted via a mechanism (M5). A speed change operation mechanism (M4) for continuously changing the speed;
In a continuously variable transmission (T) for a bicycle comprising:
The transmission mechanism (M5) has a link mechanism including a link (62) pivotally connected to the pivot (53), and the operating force is transmitted to the pivot (53) via the link mechanism. A continuously variable transmission for bicycles (T).

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