Human-powered vehicle provided with continuously variable transmission

Abstract

A bicycle 10 is a human-powered vehicle comprising a continuously variable transmission 23 which performs gear shifting on an axle 14c and includes: a driving-side pulley 31 provided on a crankshaft 21a (drive shaft); a driven-side pulley 51 provided on the axle 14c (driven shaft) driven by the crank shaft 21a; and a V-belt 23c (transmission member) suspended on the driving-side pulley 31 and the driven-side pulley 51 to transmit human power applied to the crank shaft 21a to the axle 14c. The driving-side pulley 31 and the driven-side pulley 51 each comprise a variable pulley and a fixed pulley. The bicycle 10 further includes a gear shift adjustment unit 38 that automatically moves a driving-side variable pulley 33 relative to a drive-side fixed pulley 32 along the axial direction of the crank shaft 21a to adjust the gear shifting.

Description

Human-powered vehicle equipped with a continuously variable transmission

[0001] The present specification relates to a human-powered vehicle equipped with a continuously variable transmission.

[0002] As one type of manpowered vehicle equipped with a continuously variable transmission, Patent Document 1 discloses a bicycle equipped with a continuously variable transmission, which includes a drive pulley (4) mounted on a drive shaft (3), a driven pulley (5) mounted on a driven shaft driven by the drive shaft, and a power transmission member (15: a drive V-belt) mounted on the drive pulley and the driven pulley to transmit human power applied to the drive shaft to the driven shaft, and which changes the speed of the drive shaft. The drive pulley also includes a variable pulley (9) and a fixed pulley (8). The distance between the fixed pulley piece (8) and the movable pulley piece (9) is adjusted by a manual speed change operation means.

[0003] JP 2008-183995 A

[0004] Although the bicycle described in the above-mentioned Patent Document 1 has manual gear shifting, there has been a demand for automated gear shifting to improve user convenience.

[0005] In view of the above circumstances, this specification discloses a manpowered vehicle equipped with a continuously variable transmission that can automatically change gears.

[0006] This specification discloses a manpowered vehicle equipped with a continuously variable transmission that includes a drive pulley provided on a drive shaft, a driven pulley provided on a driven shaft driven by the drive shaft, and a transmission member mounted on the drive pulley and the driven pulley for transmitting human power applied to the drive shaft to the driven shaft, and that changes the speed of the driven shaft, wherein the drive pulley and the driven pulley each include a variable pulley and a fixed pulley, and the manpowered vehicle further includes a speed adjustment unit that automatically moves the drive side variable pulley, which is the variable pulley of the drive side pulley, relative to the drive side fixed pulley, which is the fixed pulley of the drive side pulley, along the axial direction of the drive shaft to adjust the speed change.

[0007] According to the present disclosure, since the speed adjustment unit can automatically change speeds, it is possible to provide a human-powered vehicle equipped with a continuously variable transmission that can automatically change speeds.

[0008] In addition, in a human-powered vehicle equipped with a continuously variable transmission according to the present disclosure, the speed change adjustment unit includes a cam mechanism having a rotational or linearly moving cam and a follower that is linearly moved by the cam and can move the drive-side variable pulley relatively, and a speed change drive source that drives the cam to move the drive-side variable pulley relatively. This allows the drive-side variable pulley to be automatically moved with a relatively simple structure.

[0009] Furthermore, in a human-powered vehicle equipped with a continuously variable transmission according to the present disclosure, the cam mechanism and the speed-change drive source are arranged along a frame that supports the drive shaft, allowing the cam mechanism and the speed-change drive source, i.e., the speed-change adjustment unit, to be positioned optimally so as not to interfere with the rider's operation.

[0010] In addition, in a human-powered vehicle equipped with a continuously variable transmission according to the present disclosure, the speed change adjustment unit includes a cam mechanism having a cam that moves linearly in a first direction and a follower that moves linearly in a second direction different from the first direction and is connected to a pressing member that can press the drive side variable pulley, and a speed change drive source that drives the cam to move the drive side variable pulley relatively. This allows the cam mechanism to be formed relatively simply and with high durability, and the speed change adjustment unit to be formed relatively simply and with high durability.

[0011] In addition, in a human-powered vehicle equipped with a continuously variable transmission according to the present disclosure, the cam mechanism has a main body portion whose base end is connected to the output shaft of the transmission drive source and which moves linearly along the first direction, and a pressing member capable of pressing the drive-side variable pulley along the second direction, the cam being provided on the main body portion, and the follower being provided on the pressing member in a protruding manner along the second direction. This makes it possible to form the cam mechanism more simply and with high durability, and to form the transmission adjustment unit more simply and with high durability.

[0012] In addition, in a human-powered vehicle equipped with a continuously variable transmission according to the present disclosure, the main body is tapered, and the cam is provided on an inclined surface formed on the main body at a predetermined angle with respect to the first direction, which makes it possible to form a cam mechanism more simply and with high durability.

[0013] In addition, in a human-powered vehicle equipped with a continuously variable transmission according to the present disclosure, the inclined surface is formed into a predetermined concave or convex curved surface, which allows the follower, which is moved linearly by the cam, to move linearly in a desired manner.

[0014] Furthermore, in a human-powered vehicle equipped with a continuously variable transmission according to the present disclosure, the cam mechanism and the transmission drive source are disposed within the frame, allowing the cam mechanism and the transmission drive source, i.e., the transmission adjustment unit, to be disposed in an optimal location that does not interfere with the rider's operation.

[0015] Furthermore, in a human-powered vehicle equipped with a continuously variable transmission according to the present disclosure, the frame includes a crankcase that rotatably houses the drive shaft and is capable of housing the cam mechanism. This allows the cam mechanism to be housed within the crankcase, i.e., the frame, and allows the cam mechanism and the speed-changing drive source to be housed within the frame with a simple structure, while also improving design.

[0016] In addition, in a human-powered vehicle equipped with a continuously variable transmission according to the present disclosure, the drive-side variable pulley and the drive-side fixed pulley face each other, are axially movable relative to each other and engageable with each other, and each have a generally fan-shaped convex portion and a generally fan-shaped concave portion engageable with the convex portion, and the convex portion has a friction surface-side concave portion and / or a friction surface-side convex portion formed on the friction surface side with the transmission member. This makes it possible to maintain high frictional force between the transmission member and the drive-side variable pulley, thereby maintaining high transmission efficiency.

[0017] In addition, in a human-powered vehicle equipped with a continuously variable transmission according to the present disclosure, the fixed drive pulley is fitted and fixed to one end of a center boss, and the variable drive pulley is assembled onto the center boss via a slide bush so as to be rotationally restricted and axially slidable. This allows the fixed drive pulley and the variable drive pulley to be assembled onto the center boss in advance to form a sub-unit, making it possible to assemble the drive pulley easily and accurately.

[0018] Furthermore, in a human-powered vehicle equipped with a continuously variable transmission according to the present disclosure, the drive-side variable pulley and the drive-side fixed pulley each have a generally fan-shaped convex portion and a generally fan-shaped concave portion that can mesh with the convex portion, and a recess is formed on the bottom surface of the concave portion that corresponds to the convex portion that meshes with it. By leaving the bottom surface of the concave portion unremoved, the strength of the bottom surface side is maintained high, and when the drive-side variable pulley and the drive-side fixed pulley are closed, the convex portion enters the recess, so the thickness of the drive-side pulley can be kept small.

[0019] In addition, in a manpowered vehicle equipped with a continuously variable transmission according to the present disclosure, the fixed driven pulley, which is the fixed pulley of the driven pulley, is fitted and fixed to one end of a sliding sleeve, and the variable driven pulley, which is the variable pulley of the driven pulley, is assembled onto the sliding sleeve via a slide bush so as to be rotationally restricted and axially slidable. This allows the fixed driven pulley and the variable driven pulley to be assembled onto the center boss in advance to form a sub-unit, thereby making it possible to assemble the driven pulley easily and accurately.

[0020] Furthermore, in a manpowered vehicle equipped with a continuously variable transmission according to the present disclosure, the manpowered vehicle further includes a tension maintaining unit that maintains tension in the power transmission member by moving the variable driven pulley, which is the variable pulley of the driven pulley, relative to the fixed driven pulley, which is the fixed pulley of the driven pulley, along the axial direction of the driven shaft, and the tension maintaining unit has a biasing member that biases the variable driven pulley toward the fixed driven pulley. This allows the tension maintaining unit to be formed with a relatively simple structure.

[0021] In addition, in the manpowered vehicle equipped with the continuously variable transmission according to the present disclosure, the biasing member is a coil spring, which allows the tension maintaining portion to be formed with a simpler structure.

[0022] Furthermore, in a manpowered vehicle equipped with a continuously variable transmission according to the present disclosure, the variable pulley includes a first sliding support portion that supports the variable pulley slidably in the axial direction relative to the fixed pulley, and a second sliding support portion that is a portion different from the first sliding support portion and supports the variable pulley slidably in the axial direction relative to the fixed pulley. This allows the variable pulley to be slidably supported on the fixed pulley at two points (two locations), the first sliding support portion and the second sliding support portion, so the variable pulley can be slidably supported without tilting in the axial direction (and therefore the fixed pulley). This makes it possible to prevent unnecessary wear due to sliding between the variable pulley and the fixed pulley.

[0023] Furthermore, in a human-powered vehicle equipped with a continuously variable transmission according to the present disclosure, the first sliding support portion is configured as a cylindrical member that is press-fitted into the central through hole of the variable pulley and that slides on a cylindrical sliding sleeve that rotates integrally with the fixed pulley, and the second sliding support portion is a ridge portion that is formed along the axial direction at a position radially outward from the central through hole of the variable pulley, and is configured so that a sliding engagement portion of a slider housing that rotates integrally with the variable pulley can slide on it. This makes it possible to reliably slidably support the variable pulley at two points (two locations) relative to the fixed pulley with a simple configuration.

[0024] 5B is a left side view of a bicycle 10 according to the present disclosure. FIG. 6 is a top view of the bicycle 10 shown in FIG. 1. FIG. 7 is a right side view of the bicycle 10 shown in FIG. 1. FIG. 8 is a left side view of the right crank 21c shown in FIG. 1. FIG. 9 is a top view of the continuously variable transmission 23 shown in FIG. 1 in a low gear state. FIG. 10 is a top view of the continuously variable transmission 23 shown in FIG. 1 in a high gear state. FIG. 11 is a right side view of the continuously variable transmission 23 shown in FIG. 1 in a low gear state. FIG. 12 is a right side view of the continuously variable transmission 23 shown in FIG. 1 in a high gear state. FIG. 13 is a cross-sectional view taken along line 6A-6A showing the low gear state in which the drive unit 23a shown in FIG. 5C is attached to the bottom bracket 22. FIG. 5C is a cross-sectional view taken along line 6B-6B showing the high gear state in which the drive unit 23a shown in FIG. 5D is attached to the bottom bracket 22. FIG. 7 is an exploded perspective view of the drive unit 23a and drive assist unit 16 shown in FIG. 1. FIG. 8 is a right side view of the drive side fixed pulley 32 shown in FIG. 7. 8B. A cross-sectional view taken along line 8C-8C of the drive side fixed pulley 32 shown in FIG. 8B. A left side view of the drive side variable pulley 33 shown in FIG. 7. A right side view of the drive side variable pulley 33 shown in FIG. 7. A cross-sectional view taken along line 8F-8F of the drive side variable pulley 33 shown in FIG. 8D. A top view, viewed from diagonally rear, showing the shift rake 42 to which the shift shaft 44b shown in FIG. 7 is assembled. An exploded perspective view showing the driven part 23b shown in FIG. 1. A right side view of the driven side fixed pulley 52 shown in FIG. 10. A left side view of the driven side fixed pulley 52 shown in FIG. 10. A cross-sectional view taken along line 11C-11C of the driven side fixed pulley 52 shown in FIG. 11A. A left side view of the driven side variable pulley 53 shown in FIG. 10. A cross-sectional view taken along line 11E-11E of the driven side variable pulley 53 shown in FIG. 11D. A block diagram of the control device 17 shown in FIG. 1. A right side view of a drive side fixed pulley 132 according to a modified example. 13B is a left side view of a drive side fixed pulley 132 according to a modified example. FIG. 13C is a cross-sectional view taken along line 13C-13C of the drive side fixed pulley 132 shown in FIG. 13A. FIG. 13D is a cross-sectional view taken along line 13F-13F of the drive side variable pulley 133 shown in FIG. 13C. FIG. 13E is a top view showing a high gear state of a continuously variable transmission 223 according to a modified example.15 is a cross-sectional view showing a low gear state in which the drive unit 223a shown in FIG. 14 is attached to the bottom bracket 22. FIG. 16 is a cross-sectional view showing a high gear state in which the drive unit 223a shown in FIG. 14 is attached to the bottom bracket 22. FIG. 17 is an exploded perspective view showing the drive unit 223a shown in FIG. 14. FIG. 18 is a top view showing a shift rake 342 according to a modified example with a shift shaft 44b assembled thereto, as viewed diagonally from the rear. FIG. 19 is an external perspective view showing a frame 411 according to a modified example (without the down tube cover 72), as viewed diagonally from the upper right front side. FIG. 20 is an external perspective view showing a frame 411 according to a modified example (with the crankcase cover 71 and the down tube cover 72), as viewed diagonally from the upper right front side. FIG. 21 is an external perspective view showing a frame 411 according to a modified example (with the crankcase cover 71 and the down tube cover 72), as viewed diagonally from the upper left front side. FIG. 22 is a top view showing the down tube 411d shown in FIG. 18. FIG. 23 is an external perspective view showing the crankcase 60 shown in FIG. 18. FIG. 24 is a left side view showing the crankcase 60 shown in FIG. 24. FIG. 25 is a right side view showing the crankcase 60 shown in FIG. 25. 23. A cross-sectional view taken along line 25-25 of the crankcase 60 shown in FIG. 23. A cross-sectional view taken along line 26-26 of the crankcase 60 (with push plate 443a) shown in FIG. 22. A cross-sectional view taken along line 27-27 of the crankcase 60 (with the shift rake 42 housed) shown in FIG. 26. A right side view of the crankcase cover 71 shown in FIG. 20. A cross-sectional view taken along line 29-29 of the crankcase cover 71 shown in FIG. 28. A left side view of the down tube cover 72 shown in FIG. 19. An external perspective view of the down tube cover 72 shown in FIG. 19, viewed from the upper right rear. A right side view of the frame 411 according to a modified example, equipped with the crankcase cover 71 and the long down tube cover 572. An external perspective view of a drive unit 630 according to a modified example. An exploded perspective view of the drive unit 630 according to the modified example shown in FIG. 33. An exploded perspective view of a driven unit 650 according to a modified example.

[0025] (Embodiment) An embodiment of a bicycle 10 incorporating a human-powered vehicle equipped with a continuously variable transmission according to the present disclosure will be described below with reference to the drawings. A human-powered vehicle is a vehicle that has at least one wheel and can be driven by human power. Examples of human-powered vehicles include bicycles, tricycles, and wheelchairs. Human-powered vehicles also include vehicles that use not only human power but also driving forces such as electric motors for propulsion. Note that in the following description, left and right are based on the rider riding on the vehicle, and differ from left and right in the simplified description of the drawings (left and right when the bicycle 10 is viewed from the front).

[0026] (Bicycle) As shown in FIGS. 1 to 3, the bicycle 10 is a continuously variable speed bicycle, and includes a frame 11, a front portion 12, wheels 13 and 14, a drive train 15, a drive assist portion 16, and a control device 17.

[0027] (Frame) The frame 11 is a frame-like structure that forms the framework of the bicycle, and includes a head tube 11a, a seat tube 11b, a top tube 11c, a down tube 11d, an upper stay 11e, and a lower stay 11f.

[0028] The head tube 11a is cylindrical (e.g., pipe-shaped) and extends diagonally upward and rearward, supporting a front fork 12c that rotatably supports a front wheel 13. The seat tube 11b is cylindrical (e.g., pipe-shaped) and extends diagonally upward and rearward, supporting a saddle 11h via a seat post 11g. The seat post 11g is cylindrical (e.g., pipe-shaped) and slidably disposed within the seat tube 11b, and is positioned and fixed at a position desired by the rider. The saddle 11h, on which the rider can sit, is fixed to the upper end of the seat post 11g.

[0029] The lower end of the seat tube 11b rotatably supports the crank 21. As shown in Figure 2, a cylindrical hanger portion 11i extending in the left-right direction is provided at the lower end of the seat tube 11b. A bottom bracket 22, which rotatably supports the crankshaft 21a, is inserted and fixed into the hanger portion 11i.

[0030] 1 and 3, the top tube 11c is formed in a cylindrical shape (e.g., a pipe shape) and connects the upper end of the head tube 11a to the upper end of the seat tube 11b. The down tube 11d is formed in a cylindrical shape (e.g., a pipe shape) and connects the lower end of the head tube 11a to the lower end of the seat tube 11b.

[0031] The upper stay 11e is a stay that rotatably supports the rear wheel 14 on the seat tube 11b. Specifically, as shown in FIG. 2, the upper stay 11e has a pair of opposing left and right upper stays 11e1, 11e2 that are arranged to sandwich the rear wheel 14. Each of the left and right upper stays 11e1, 11e2 is formed in a cylindrical (e.g., pipe) shape, and one end (upper end) of each of the left and right upper stays 11e1, 11e2 is connected to the upper end of the seat tube 11b. The other end (lower end) of each of the left and right upper stays 11e1, 11e2 is formed with mounting portions 11e1a, 11e2a that are formed by flattening a cylindrical member, and the mounting portions 11e1a, 11e2a are detachably connected to both left and right ends of the axle 14c of the rear wheel 14, for example, by bolting.

[0032] The lower stay 11f is a stay that rotatably supports the rear wheel 14 on the seat tube 11b and also reinforces the upper stay 11e, and is disposed below the upper stay 11e. Specifically, the lower stay 11f has a pair of opposing left and right lower stays 11f1, 11f2 that are disposed so as to sandwich the rear wheel 14. The left and right lower stays 11f1, 11f2 are each formed in a cylindrical shape (e.g., a pipe shape), and one end (front end) of each of the left and right lower stays 11f1, 11f2 is connected to the lower end of the seat tube 11b.

[0033] The other end (rear end) of each of the left and right lower stays 11f1, 11f2 is connected to the other end (lower end) of each of the left and right upper stays 11e1, 11e2. In particular, it is preferable that the connection position of the other end of the right lower stay 11f2 be set to a position higher than the vertical position where the highest V-belt 23c (in the case of low gear shown in FIG. 5A ) intersects with the right upper stay 11e2. This eliminates the need to significantly bend the right lower stay 11f2 to prevent interference with the V-belt 23c (by preventing the right lower stay 11f2 from protruding significantly to the right), thereby ensuring sufficient pedal space for the occupant and improving design.

[0034] Incidentally, if the connection position of the other end of the right lower stay 11f2 is set to a position lower than the above-mentioned vertical intersecting position, it becomes necessary to pass the V-belt 23c between the right upper stay 11e2 and the right lower stay 11f2 (see FIG. 1). In contrast, by setting the connection position of the other end of the right lower stay 11f2 to a position higher than the above-mentioned vertical intersecting position, it becomes possible to easily install and replace the V-belt 23c without having to cut it midway, pass it between the right upper stay 11e2 and the right lower stay 11f2, and then reconnect it.

[0035] The other ends of the left and right lower stays 11f1, 11f2 may be connected to both left and right ends of the axle 14c of the rear wheel 14. In this case, the right lower stay 11f2 may be formed to protrude to the right in order to prevent interference with the V-belt 23c.

[0036] 1 and 2, the front section 12 has a handlebar 12a, a stem 12b, and a front fork 12c. The handlebar 12a is formed in a rod shape and is operated by the rider to steer the bicycle 10. The center of the handlebar 12a in the left-right direction is fixed to the upper end of the front fork 12c via the stem 12b.

[0037] The front fork 12c has a steering column 12c1, a crown 12c2, and a pair of left and right blades 12c3 and 12c4.

[0038] The steering column 12c1 is formed in a cylindrical (e.g., pipe) shape and is configured to be insertable into the head tube 11a. The steering column 12c1 is rotatably supported within the head tube 11a. The handlebars 12a are connected to the upper end of the steering column 12c1 via a stem 12b. A pair of left and right blades 12c3, 12c4 are connected to the lower end of the steering column 12c1 via a crown 12c2.

[0039] As shown in Fig. 2, the pair of left and right blades 12c3, 12c4 are arranged to sandwich the front wheel 13. Each of the left and right blades 12c3, 12c4 is formed in a cylindrical shape (e.g., a pipe shape), and one end (upper end) of each of the left and right blades 12c3, 12c4 is connected to both left and right ends of the crown 12c2. The other end (lower end) of each of the left and right blades 12c3, 12c4 is connected to both left and right ends of the axle 13c of the front wheel 13.

[0040] (Wheels) The wheels 13, 14 constitute the front and rear wheels, respectively, as shown mainly in Figures 1 and 2. The wheels 13 may be referred to as the front wheels 13, and the wheels 14 may be referred to as the rear wheels 14. The front wheels 13 include a wheel 13a, a tire 13b, and an axle (front wheel shaft) 13c. The tire 13b is made of rubber and is formed in a semicircular cross section and an annular shape.

[0041] The wheel 13a has a rim 13a1, a hub 13a2, and spokes 13a3. The rim 13a1 is formed in an annular shape with an arc-shaped (semi-arc-shaped) cross section. The outer peripheral wall of the rim 13a1 is open radially outward, and the tire 13b is attached to the outer periphery of the rim 13a1 so as to cover the outer peripheral wall of the rim 13a1.

[0042] The hub 13a2 is cylindrically formed so that the axle 13c can be inserted therethrough and is rotatably supported by the axle 13c. The hub 13a2 is connected to the rim 13a1 via a plurality of spokes 13a3 made of metal and formed in a wire shape. The hub 13a2 is disposed concentrically with the rim 13a1.

[0043] The rear wheel 14 includes a wheel 14a, a tire 14b, and an axle (rear wheel axle) 14c, similar to the front wheel 13. The wheel 14a includes a rim 14a1, a hub 14a2 (see FIG. 2), and spokes 14a3, similar to the wheel 13a.

[0044] 1 to 3, the drivetrain 15 mainly includes a hanger portion 11i, a crank 21, a bottom bracket (bearing) 22 (see FIG. 2), and a continuously variable transmission 23. The drivetrain 15 transmits the rotation (force) of the crank 21, which is rotated by the pedaling force of the rider, to the rear wheel 14, which is the drive wheel, and can also change the speed of the rear wheel 14.

[0045] The crank 21 includes a cylindrical crankshaft 21a (see FIG. 2), a left crank 21b connected to the left end of the crankshaft 21a, and a right crank 21c connected to the right end of the crankshaft 21a via a center boss 34. The crankshaft 21a is a drive shaft. The left crank 21b is formed into a metal rod shape, and a base end of the left crank 21b is fixed (connected) to the left end of the crankshaft 21a. A pedal (not shown) that can be depressed by the rider is rotatably attached to a tip end of the left crank 21b.

[0046] As shown in Figure 4, the right crank 21c has a cross-shaped fixed portion 21c1 and a rod-shaped crank portion 21c2 extending outward from the fixed portion 21c1. The fixed portion 21c1 and crank portion 21c2 are made of metal and integrally formed. The fixed portion 21c1 is fixed (connected) to the right end of the crankshaft 21a via a center boss 34, and a pedal (not shown) is rotatably attached to the tip of the crank portion 21c2.

[0047] The fixed portion 21c1 has a central portion provided with a bolt fixing hole 21c3 and an engagement hole 21c4 formed within the bolt fixing hole 21c3. The bolt fixing hole 21c3 has a stepped surface with which the head of the bolt 39 engages. The engagement hole 21c4 is fitted with an engagement protrusion 34b of the center boss 34. A bolt insertion hole 21c5 is formed at the tip end of each leg of the fixed portion 21c1 at a position corresponding to the screw hole 32b1 of the drive-side fixed pulley 32. An engagement protrusion 21c6 is formed at the base end of each leg of the fixed portion 21c1 to engage with a positioning hole 32b2 for positioning the right crank 21c on the drive-side fixed pulley 32. This makes it possible to reliably position the right crank 21c at a predetermined position on the drive-side fixed pulley 32 and to reliably secure it with a screw.

[0048] The bottom bracket 22 is a bearing that rotatably supports the crank 21 on the frame 11. The bottom bracket 22 is inserted into and fixed to a cylindrical hanger portion 11i provided at the lower end of the seat tube 11b, and rotatably supports the crank axle 21a. The hanger portion 11i is preferably provided at the connection between the seat tube 11b and the down tube 11d. The bottom bracket 22 with the crank axle 21a already attached thereto is called a bottom bracket assembly, and the bottom bracket assembly may be attached to the hanger portion 11i.

[0049] As shown in Figures 6A and 6B, the bottom bracket 22 has a case 22a, a bearing 22b, and an assist driven gear 16c. The case 22a is cylindrical. Bearings 22b are provided on both the left and right ends of the case 22a, and the bearings 22b rotatably support the crankshaft 21a. The assist driven gear 16c is provided on the right end of the crankshaft 21a so as to rotate integrally with it.

[0050] 5A to 5D, the continuously variable transmission 23 includes a driving unit 23a that is assembled to the crank 21 and includes a driving pulley 31 that rotates integrally with the crank 21, a driven unit 23b that is assembled to the rear wheel axle 14c and includes a driven pulley 51 that rotates integrally with the rear wheel axle 14c, and a V-belt 23c that is a transmission member that is mounted on the driving unit 23a and the driven unit 23b and transmits the pedaling force (human power) applied to the crank 21 to the rear wheel axle 14c (rear wheel 14).

[0051] (Drive Unit) As shown in FIG. 7, the drive unit 23a (30) mainly includes a drive-side pulley 31, a center boss 34, a drive-side slide bush 35, a thrust bearing 36, a thrust washer 37, and a speed change adjustment unit 38 (40).

[0052] (Drive Side Pulley) The drive side pulley 31 has a drive side fixed pulley 32 that is the fixed pulley of the drive side pulley 31, and a drive side variable pulley 33 that is the variable pulley of the drive side pulley 31. The drive side fixed pulley 32 is fitted and fixed to one end (right end) of a center boss 34 that fixedly connects the crankshaft 21a and the right crank 21c (see FIG. 2). The drive side variable pulley 33 is attached to the center boss 34 via a drive side slide bush 35 that is slidable along the axial direction of the center boss 34 but is restricted from rotating about the axis.

[0053] (Drive side fixed pulley) As shown in Figures 8A to 8C, the drive side fixed pulley 32 is formed in a substantially conical disk shape, and has a pulley body 32a formed in a conical disk shape, a circular protrusion 32b formed coaxially with the pulley body 32a and protruding from the bottom surface 32a2, and a stepped through hole 32c formed in the center coaxially with the pulley body 32a.

[0054] The pulley body 32a has a conical surface 32a1 and a bottom surface 32a2, which are friction surfaces. Concave portions 32d and convex portions 32e, each of which is formed in a generally fan-shaped configuration when viewed from the left side in FIG. 8C , are alternately formed along the circumferential direction on the conical surface 32a1. A plurality of concave portions 32d are formed along the circumferential direction at a predetermined angle α2. The apex angle of each concave portion 32d is set to a predetermined angle α1. A plurality of convex portions 32e are formed along the circumferential direction at a predetermined angle α1. The apex angle of each convex portion 32e is set to a predetermined angle α2. The predetermined angle α1 and the predetermined angle α2 are set to the same value.

[0055] (Recess) As shown in FIG. 8C, recess 32d opens to the left, and as shown in FIG. 8A, the outer peripheral end of recess 32d extends to the inner circumference of conical outer annular portion 32a3 having a predetermined width, and the inner peripheral end of recess 32d extends to the inner circumference of large diameter hole portion 32c1 (the outer peripheral wall surface of inner cylindrical portion 32f).

[0056] As shown in FIGS. 8A to 8C, the recess 32d has an inner peripheral wall surface 32d1, an outer peripheral wall surface 32d2, a first side wall surface 32d3, a second side wall surface 32d4, a bottom surface 32d5, and an opening 32d6.

[0057] As shown in Fig. 8A, the inner peripheral wall surface 32d1 is an outer peripheral wall surface formed on the inner cylindrical portion 32f at a predetermined angle α1 and spaced a predetermined distance from the inner cylindrical portion 32f. As shown in Fig. 8C, the inner peripheral wall surface 32d1 is formed in the axial direction (the axial direction of the drive-side fixed pulley 32) from a left end surface 32f1, which is one end surface of the inner cylindrical portion 32f, to a bottom surface 32d5.

[0058] As shown in Fig. 8A, the outer peripheral wall surface 32d2 is an inner peripheral wall surface formed at a predetermined angle α1 and a predetermined distance (predetermined angle α2) from the conical outer annular portion 32a3. As shown in Fig. 8C, the outer peripheral wall surface 32d2 is formed in the axial direction from the conical surface 32a1 to the bottom surface 32a2.

[0059] As shown in Fig. 8A, the first side wall surface 32d3 extends radially from the inner circumferential wall surface 32d1 to the outer circumferential wall surface 32d2. As shown in Fig. 8C, the first side wall surface 32d3 extends axially from the conical surface 32a1 to the bottom surface 32d5 or the bottom surface 32a2.

[0060] As shown in FIG. 8A, the second side wall surface 32d4 extends radially of the pulley body 32a. The second side wall surface 32d4 faces the first side wall surface 32d3 and is disposed at a predetermined angle α1. The second side wall surface 32d4 extends radially (in the radial direction of the drive-side fixed pulley 32) from the inner circumferential wall surface 32d1 to the outer circumferential wall surface 32d2. The second side wall surface 32d4 extends axially from the conical surface 32a1 to the bottom surface 32d5 or the bottom surface 32a2 (see FIG. 8C).

[0061] An opening 32d6 that is U-shaped and opens radially inward is provided between the inner end of the first side wall surface 32d3, the inner end of the second side wall surface 32d4, and the left end of the inner wall surface 32d1 (the outer peripheral end of the left end surface 32f1 of the inner cylindrical portion 32f).

[0062] As shown in Fig. 8A, the bottom surface 32d5 is provided by connecting the first side wall surface 32d3 and the second side wall surface 32d4. The bottom surface 32d5 is provided by extending outward from the inner circumferential wall surface 32d1 in the radial direction (the radial direction of the drive-side fixed pulley 32). The outer peripheral edge of the bottom surface 32d5 is open, and a space 32d7 is formed between the bottom surface 32d5 and the outer circumferential wall surface 32d2. The bottom surface 32d5 is formed into an annular, inclined surface.

[0063] As shown in FIG. 8C , the bottom surface 32d5 of the recess 32d is an inclined surface that tapers outward. A recess 32h corresponding to the top of the meshing protrusion 33e (see FIG. 8F ) is formed on this bottom surface 32d5 to allow the top of the protrusion 33e to escape when the meshing protrusion 33e enters the recess 32d. The depth and inclination of the recess 32h are set within a range that prevents the recess 32h from reaching the bottom surface of the circular protrusion 32b, and the depth is preferably set to a value that allows the top of the protrusion 33e to enter (accommodate) as much as possible. The bottom surface 32d5 is also formed parallel to the third side wall surface (upper wall surface) 33e5, which is the friction surface 33a1 of the protrusion 33e. This allows the strength of the bottom side of the recess 32d, and therefore the strength of the drive side fixed pulley 32, to be maintained high by leaving the thickness from the bottom surface 32d5 (relief portion 32h) of the recess 32d to the bottom surface of the circular protrusion 32b, and also allows the thickness of the drive side pulley 31 in the closed state (see Figures 5B and 6A) to be kept small because the top of the protrusion 33e enters the relief portion 32h when the drive side variable pulley 33 and the drive side fixed pulley 32 are closed.

[0064] (Convex portion) As shown in FIG. 8C, the convex portion 32e protrudes toward the left, and the outer peripheral end of the convex portion 32e extends to the inner circumference of the conical outer annular portion 32a3 having a predetermined width, and the inner peripheral end of the convex portion 32e extends to the inner circumference of the large diameter hole portion 32c1 (an extension line of the outer peripheral wall surface of the inner cylindrical portion 32f).

[0065] As shown in FIGS. 8A to 8C, the protrusion 32e has an inner peripheral wall surface 32e1, a first side wall surface 32e3, a second side wall surface 32e4, a third side wall surface (upper wall surface) 32e5, and a fourth side wall surface (lower side surface) 32e6.

[0066] As shown in Fig. 8A, the inner peripheral wall surface 32e1 is an inner peripheral wall surface formed on the protrusion 32e at a predetermined angle α2. As shown in Fig. 8C, the inner peripheral wall surface 32e1 is provided in the axial direction (the axial direction of the drive-side fixed pulley 32) from the conical surface 32a1 to the bottom surface 32d5 of the recess 32d. The right half of the inner peripheral wall surface 32e1 (the portion to the right of the left end surface 32f1, which is one end surface of the inner cylindrical portion 32f) is integrally connected to the outer peripheral wall surface of the inner cylindrical portion 32f.

[0067] As shown in Fig. 8A, the first side wall surface 32e3 extends radially from the pulley body 32a. The first side wall surface 32e3 is formed radially from the inner peripheral wall surface 32e1 to the outer peripheral wall surface 32d2. As shown in Fig. 8C, the first side wall surface 32e3 is formed axially from the conical surface 32a1 to the bottom surface 32d5 or the bottom surface 32a2. The first side wall surface 32e3 is identical to the second side wall surface 32d4 of the recess 32d.

[0068] As shown in FIG. 8A , the second side wall surface 32e4 extends radially of the pulley body 32a. The second side wall surface 32e4 is disposed on the side opposite the first side wall surface 32e3 at a predetermined angle α2. The second side wall surface 32e4 extends radially from the inner circumferential wall surface 32e1 to the outer circumferential wall surface 32d2. The second side wall surface 32e4 extends axially from the conical surface 32a1 to the bottom surface 32d5 or the bottom surface 32a2. The second side wall surface 32e4 is identical to the first side wall surface 32d3 of the recess 32d.

[0069] The third side wall surface (upper wall surface) 32e5 connects one end edge (left edge) of the first side wall surface 32e3 to one end edge (left edge) of the second side wall surface 32e4. The fourth side wall surface (lower surface) 32e6 connects the other end edge (right edge) of the first side wall surface 32e3 to the other end edge (right edge) of the second side wall surface 32e4.

[0070] The circular protrusion 32b is formed in a disk shape and protrudes coaxially and integrally from the bottom surface 32a2 of the pulley body 32a. The bottom surface of the circular protrusion 32b is provided with a plurality of (four in this embodiment) screw holes 32b1 for screwing the right crank 21c, and a plurality of (four in this embodiment) positioning holes 32b2 for positioning the right crank 21c.

[0071] The through hole 32c has a large diameter hole portion 32c1, a medium diameter hole portion 32c2 having a smaller diameter than the large diameter hole portion 32c1, and a small diameter hole portion 32c3 having a smaller diameter than the medium diameter hole portion 32c2. The large diameter hole portion 32c1, the medium diameter hole portion 32c2, and the small diameter hole portion 32c3 are provided in this order from left to right as shown in FIG.

[0072] Specifically, the through hole 32c is provided with a cylindrical inner tube portion 32f, and one end surface 32f1 (left end surface 32f1) of the inner tube portion 32f is located in the left-right center of the inner circumferential wall surface 32e1 of the protrusion 32e. The other end surface 32f2 (right end surface 32f2) of the inner tube portion 32f is formed flush with the bottom surface of the circular protrusion 32b. The other end (right end) of the inner tube portion 32f is provided with an annular flange portion 32g extending inward. The inner circumferential wall surface 32e1 of each protrusion 32e defines the large-diameter hole portion 32c1, the inner circumferential wall surface of the inner tube portion 32f defines the medium-diameter hole portion 32c2, and the inner circumferential wall surface of the flange portion 32g defines the small-diameter hole portion 32c3.

[0073] The inner peripheral wall surface of the inner cylindrical portion 32f is provided with a plurality of (six in this embodiment) axially extending ridges 32f3 at predetermined intervals along the circumferential direction. The ridges 32f3 are engaged with an engaging groove 34a of the center boss 34, and the drive-side fixed pulley 32 is fixed to the center boss 34 while restricting its rotation.

[0074] (Drive Side Variable Pulley) As shown in Figures 8D to 8F, the drive side variable pulley 33 is formed in a substantially conical disk shape, and has a pulley body 33a formed in a conical disk shape, a circular protrusion 33b formed coaxially with the pulley body 33a and protruding from a bottom surface 33a2, and a stepped through hole 33c formed in the center coaxially with the pulley body 33a.

[0075] The pulley body 33a has a conical surface 33a1 and a bottom surface 33a2, which are friction surfaces. Concave portions 33d and convex portions 33e, each of which is formed in a generally fan-shaped configuration when viewed from the right side in FIG. 8F, are alternately formed along the circumferential direction on the conical surface 33a1. A plurality of concave portions 33d are formed along the circumferential direction at a predetermined angle α2. The apex angle of each concave portion 33d is set to a predetermined angle α1. A plurality of convex portions 33e are formed along the circumferential direction at a predetermined angle α1. The apex angle of each convex portion 33e is set to a predetermined angle α2. The predetermined angle α1 and the predetermined angle α2 are set to the same value.

[0076] (Recess) As shown in FIG. 8F, recess 33d is open to the right, and as shown in FIG. 8D, the outer peripheral end of recess 33d extends to the inner circumference of conical outer annular portion 33a3 having a predetermined width, and the inner peripheral end of recess 33d extends to the inner circumference of large diameter hole portion 33c1.

[0077] As shown in FIGS. 8D to 8F, the recess 33d has an inner peripheral wall surface 33d1, an outer peripheral wall surface 33d2, a first side wall surface 33d3, a second side wall surface 33d4, a bottom surface 33d5, and an opening 33d6.

[0078] The inner peripheral wall surface 33d1 is an outer peripheral wall surface formed at a predetermined angle α1 on the inner cylindrical portion 33f at a predetermined interval. As shown in FIG. 8F , the inner peripheral wall surface 33d1 extends from a right end surface 33f1, which is the other end surface of the inner cylindrical portion 33f, to a bottom surface 33d5.

[0079] As shown in Fig. 8D, the outer peripheral wall surface 33d2 is an inner peripheral wall surface formed at a predetermined angle α1 and a predetermined distance (predetermined angle α2) from the conical outer annular portion 33a3. As shown in Fig. 8F, the outer peripheral wall surface 33d2 is formed in the axial direction from the conical surface 33a1 to the bottom surface 33a2.

[0080] As shown in Fig. 8D, the first side wall surface 33d3 extends radially from the inner peripheral wall surface of the large diameter hole portion 33c1 to the outer peripheral wall surface 33d2. As shown in Fig. 8F, the first side wall surface 33d3 extends axially from the conical surface 33a1 to the bottom surface 33d5 or the bottom surface 33a2. A notch 33d3a is formed in the first side wall surface 33d3.

[0081] As shown in FIG. 8D , the second side wall surface 33d4 extends radially of the pulley body 33a. The second side wall surface 33d4 faces the first side wall surface 33d3 and is disposed at a predetermined angle α1. The second side wall surface 33d4 extends radially (in the radial direction of the drive-side variable pulley 33) from the inner peripheral wall surface of the large-diameter hole portion 33c1 to the outer peripheral wall surface 33d2. The second side wall surface 33d4 extends axially from the conical surface 33a1 to the bottom surface 33d5 or bottom surface 33a2. The second side wall surface 33d4 has a notch 33d4a formed thereon, similar to the notch 33d3a of the first side wall surface 33d3.

[0082] An opening 33d6 formed in a U-shape and opening radially inward is provided between the inner end of the first side wall surface 33d3, the inner end of the second side wall surface 33d4, and the outer peripheral end of the right end surface 33f1 of the inner cylindrical portion 33f.

[0083] As shown in Fig. 8D, the bottom surface 33d5 is provided by connecting the first side wall surface 33d3 and the second side wall surface 33d4. As shown in Fig. 8F, the bottom surface 33d5 is provided by extending outward from the outer peripheral end of the right end surface 33f1 of the inner cylindrical portion 33f in the radial direction (the radial direction of the drive-side variable pulley 33). The bottom surface 33d5 is formed into an annular, inclined surface. The outer peripheral edge of the bottom surface 33d5 is open, and a space 33d7 is formed between the bottom surface 33d5 and the outer peripheral wall surface 33d2.

[0084] The bottom surface 33d5 of the recess 33d is an inclined surface that tapers outward, and this bottom surface 33d5 is formed with a relief portion 33h corresponding to the top of the engaging protrusion 32e so that the top of the protrusion 32e can escape when the engaging protrusion 32e enters the recess 33d. The depth and inclination of the relief portion 33h are formed within a range that does not separate the large diameter portion 33b1 and the small diameter portion 33b2, and it is preferable that the depth be set to a value that allows the top of the protrusion 32e to enter as far as possible. In addition, the bottom surface 33d5 is formed so as to be parallel to the third side wall surface (upper wall surface) 32e5, which is the friction surface 32a1 of the protrusion 32e. This maintains a high strength of the bottom side of the recess 33d and therefore of the drive side variable pulley 33 by leaving the connection between the bottom surface 33d5 of the recess 33d and the inner tube portion 33f, and when the drive side variable pulley 33 and the drive side fixed pulley 32 are closed, the top of the convex portion 33e enters the recess portion 33h, so that the thickness of the drive side pulley 31 in the closed state (see Figures 5B and 6A) can be kept small.

[0085] (Convex portion) As shown in FIG. 8F, the convex portion 33e protrudes toward the right, and the outer peripheral end of the convex portion 33e extends to the inner circumference of the conical outer annular portion 33a3 having a predetermined width, and the inner peripheral end of the convex portion 33e extends to the inner circumference of the large diameter hole portion 33c1.

[0086] As shown in Figures 8D to 8F, the convex portion 33e has an inner wall surface 33e1, a first side wall surface 33e3, a second side wall surface 33e4, a third side wall surface (upper wall surface) 33e5, a fourth side wall surface (lower side surface) 33e6, and a notch portion 33e7.

[0087] As shown in FIG. 8D , the inner circumferential wall surface 33e1 is an inner circumferential wall surface formed on the convex portion 33e at a predetermined angle α2. As shown in FIG. 8F , the inner circumferential wall surface 33e1 extends rightward from a right end surface 33f1, which is the other end surface of the inner cylindrical portion 33f, to the conical surface 33a1 in the axial direction (the axial direction of the drive-side variable pulley 33). As shown in FIG. 8F , the inner circumferential wall surface 33e1 extends from the conical surface 33a1 to a bottom surface 33d5 of the recess 33d in the axial direction (the axial direction of the drive-side variable pulley 33). The left half of the inner circumferential wall surface 33e1 (the portion to the left of the right end surface 33f1, which is the other end surface of the inner cylindrical portion 33f) is integrally connected to the outer circumferential wall surface of the inner cylindrical portion 33f.

[0088] As shown in Fig. 8D, the first side wall surface 33e3 extends radially from the pulley body 33a. The first side wall surface 33e3 extends radially from the inner peripheral wall surface 33e1 to the outer peripheral wall surface 33d2. The first side wall surface 33e3 extends axially from the conical surface 33a1 to the bottom surface 33d5 or the bottom surface 33a2. The first side wall surface 33e3 is identical to the second side wall surface 33d4 of the recess 33d.

[0089] As shown in FIG. 8D, the second side wall surface 33e4 extends radially of the pulley body 33a. The second side wall surface 33e4 is disposed on the side opposite the first side wall surface 33e3 at a predetermined angle α2. The second side wall surface 33e4 extends radially from the inner circumferential wall surface 33e1 to the outer circumferential wall surface 33d2 (see FIG. 8F). The second side wall surface 33e4 extends axially from the conical surface 33a1 to the bottom surface 33d5 or the bottom surface 33a2. The second side wall surface 33e4 is identical to the first side wall surface 33d3 of the recess 33d.

[0090] The third side wall surface (upper wall surface) 33e5 connects one end edge (right edge) of the first side wall surface 33e3 to one end edge (right edge) of the second side wall surface 33e4. The fourth side wall surface (lower surface) 33e6 connects the other end edge (left edge) of the first side wall surface 33e3 to the other end edge (left edge) of the second side wall surface 33e4.

[0091] As shown in Fig. 8F, the notch 33e7 is formed as a recess that opens toward the left side in the fourth side wall surface (lower surface) 33e6. The first side wall surface 33e3 and the second side wall surface 33e4 also have notches 33e3a and 33e4a corresponding to the notch 33e7. The notch 33e7 is formed radially from the inner periphery of the conical outer annular portion 33a3 to the outer periphery of the circular protrusion 33b.

[0092] The circular protrusion 33b is formed in a stepped disk shape and protrudes coaxially and integrally from the bottom surface 33a2 of the pulley body 33a. The circular protrusion 33b has a large diameter portion 33b1 and a small diameter portion 33b2 that is smaller in diameter than the large diameter portion 33b1. A thrust washer 37, a thrust bearing 36, and a push plate 43a are mounted on the left end surface of the large diameter portion 33b1 in this order.

[0093] The through hole 33c has a large diameter hole portion 33c1 and a small diameter hole portion 33c2 that is smaller in diameter than the large diameter hole portion 33c1. The large diameter hole portion 33c1 and the small diameter hole portion 33c2 are provided in this order from right to left as shown in FIG. 8F.

[0094] Specifically, the through hole 33c is provided with a cylindrical inner tube portion 33f, and the other end surface 33f1 (right end surface 33f1) of the inner tube portion 33f is located in the left-right center of the inner circumferential wall surface 33e1 of the protrusion 33e. One end surface 33f2 (left end surface 33f2) of the inner tube portion 33f is formed flush with the bottom surface of the circular protrusion 33b. The inner circumferential wall surface 33e1 of each protrusion 33e defines the large-diameter hole portion 33c1, and the inner circumferential wall surface of the inner tube portion 33f defines the small-diameter hole portion 33c2.

[0095] The inner peripheral wall surface of the inner cylindrical portion 33f is provided with a plurality of (six in this embodiment) axially extending ridges 33f3 at predetermined intervals along the circumferential direction. The ridges 33f3 are engaged with the engaging grooves 35a of the drive-side slide bush 35, and the drive-side slide bush 35 is fixed within the drive-side variable pulley 33 while being restricted from rotating.

[0096] (Center Boss / Slide Bush) As shown primarily in Fig. 7, the center boss 34 is formed in a cylindrical shape and serves to fix the drive side fixed pulley 32 and the drive side variable pulley 33 so that they rotate integrally, and to support the drive side variable pulley 33 so that it can slide in the axial direction of the center boss 34. As shown in Figs. 6A and 6B, the center boss 34 is disposed between the crankshaft 21a and the right crank 21c, and serves to connect the crankshaft 21a and the right crank 21c.

[0097] As shown in Figure 7, the outer peripheral wall surface of the center boss 34 is provided with a plurality of (six in this embodiment) engagement grooves 34a extending axially along the center boss 34, and these engage the ridges 32f3 of the drive-side fixed pulley 32. One end (right end) of the center boss 34 is formed with an engagement protrusion 34b having a square cross section that engages with the right crank 21c, and the other end (left end) of the center boss 34 is formed with an engagement recess 34c having a square cross section that engages with the bottom bracket 22. A through hole 34d is formed in the center of the center boss 34, penetrating from the tip end surface of the engagement protrusion 34b to the bottom surface of the engagement recess 34c. A bolt 39 is inserted into the through hole 34d (see Figures 6A and 6B). The bolt 39 is threaded onto the crankshaft 21a, and the center boss 34 to which the drive side fixed pulley 32 and the drive side variable pulley 33 are attached, and the right crank 21c can be assembled to the crankshaft 21a.

[0098] As shown in Figure 7, the drive side slide bush 35 is primarily formed in a cylindrical shape and is fitted and fixed within the drive side variable pulley 33 to allow the drive side variable pulley 33 to slide smoothly on the center boss 34. A convex rib 35b that protrudes inward is formed along the axial direction on the inner peripheral wall surface of the drive side slide bush 35. The convex rib 35b engages with an engaging groove 34a of the center boss 34 so as to be slidable along the axial direction. An engaging groove 35a that corresponds to the convex rib 35b is formed along the axial direction on the outer peripheral wall surface of the drive side slide bush 35. The convex rib 33f3 of the drive side variable pulley 33 is fitted into and fixed in the engaging groove 35a.

[0099] 7, the speed change adjustment unit 38 (40) adjusts the speed by automatically moving the drive side variable pulley 33 relative to the drive side fixed pulley 32 along the axial direction (left-right direction) of the crankshaft 21a. The speed change adjustment unit 38 includes a cam mechanism 41 and a speed change drive device 44 (speed change drive source).

[0100] (Cam mechanism) As shown in FIG. 7, the cam mechanism 41 includes a cam portion 42 having a cam 41a and moving in a rotational or linear motion, and a follower portion 43 having a follower 41b that is moved in a linear motion by the cam 41a and that can move the drive side variable pulley 33 relatively.

[0101] (Cam portion (shift rake)) As shown in FIG. 7, the cam portion 42 is primarily composed of a shift rake formed in the shape of a bifurcated fork. The shift rake 42 has a T-shaped base 42a and a pair of cam main bodies 42b, 42c integrally provided at both the front and rear ends of the base 42a. The base 42a is formed in a T-shape, and a through hole 42a1 is formed along a first direction. The first direction is the same as the extension direction (longitudinal direction) of the down tube 11d (see FIG. 1, for example).

[0102] The cam main body 42b is formed in a rod shape. The base end of the cam main body 42b is connected to the rear end of the base 42a, and the cam main body 42b is provided so as to extend obliquely downward and rearward in the first direction (see FIG. 1). As shown in FIGS. 7 and 9, a tapered portion 42d is formed at the tip of the cam main body 42b. The tapered portion 42d has an inclined surface 42d1 formed so as to be tapered. The inclined surface 42d1 is formed as a flat surface. As shown in FIG. 9, the inclined surface 42d1 is formed at a predetermined angle θ with respect to an imaginary plane P1 that includes the first direction, the up-down direction, and the front-to-rear direction. The inclined surface 42d1 functions as a cam 41a that guides and follows the cam follower 43b.

[0103] The cam main body 42c is formed in a rod shape. The base end of the cam main body 42c is connected to the front end of the base 42a, and the cam main body 42c is arranged parallel to and opposite the cam main body 42b, extending diagonally downward and rearward in the first direction (see FIG. 1). A tapered portion 42e is formed at the tip of the cam main body 42c. The tapered portion 42e has an inclined surface 42e1 that is tapered. The inclined surface 42e1 is formed as a flat surface. Like the inclined surface 42d1, the inclined surface 42e1 is formed at a predetermined angle θ with respect to the imaginary plane P1. The inclined surface 42e1 functions as a cam 41a that guides and follows the cam follower 43c.

[0104] 7, the driven part 43 includes a push plate 43a that is a pressing member that can press the drive-side variable pulley 33 in the second direction (left-right direction), and a pair of cam followers 43b, 43c that are provided on the push plate 43a. The second direction is the left-right direction, which is different from the first direction and perpendicular to the first direction.

[0105] The push plate 43a is formed in the shape of an annular plate, and a through-hole 43a1 is formed in the center of the push plate 43a, into which the circular protrusion 33b of the drive-side variable pulley 33 can be inserted. A pair of support portions 43a2, 43a3 is provided on the outer circumferential edge of the push plate 43a. One support portion 43a2 is provided at one end of the outer circumferential edge of the push plate 43a, and the other support portion 43a3 is provided at the other end of the outer circumferential edge located opposite the one end of the push plate 43a. The pair of support portions 43a2, 43a3 are provided to extend leftward in the second direction.

[0106] A pair of cylindrical cam followers 43b, 43c are coaxially and rotatably provided inside the tip ends of the pair of support portions 43a2, 43a3. The pair of cam followers 43b, 43c are arranged at the same height and a first predetermined distance away from the push plate 43a. The pair of cam followers 43b, 43c are arranged so as to be spaced the same distance as the inclined surfaces 42d1, 42e1 (cam main bodies 42b, 42c). The cam follower 43b is linearly moved along the second direction by the cam 41a (inclined surface 42d1) and functions as a follower 41b that can move the drive-side variable pulley 33 relatively. The cam follower 43c is linearly moved along the second direction by the cam 41a (inclined surface 42e1) and functions as a follower 41b that can move the drive-side variable pulley 33 relatively.

[0107] As shown primarily in Figures 6A and 6B, a pair of cylindrical rollers 43d, 43e are coaxially and rotatably provided on the outer sides of the distal ends of the pair of support portions 43a2, 43a3. The pair of rollers 43d, 43e are disposed at the same height and a first predetermined distance from the push plate 43a. The roller 43d is attached by a nut 43g threaded onto the threaded portion of the cam follower 43b, with a collar 43f attached between the roller 43d and the cam follower 43b. The roller 43e is attached by a nut 43g threaded onto the threaded portion of the cam follower 43c, with a collar 43f attached between the roller 43d and the cam follower 43c.

[0108] The pair of rollers 43d, 43e have flanges formed on both ends, and the side surfaces of the pair of rollers 43d, 43e function as guided portions that are slidably guided by the pair of guide rails 11j1, 11j2. The pair of guide rails 11j1, 11j2 extend in the left-right direction, allowing the pair of rollers 43d, 43e, and therefore the push plate 43a, to reliably reciprocate in the left-right direction. The pair of guide rails 11j1, 11j2 are provided on a bracket 11j that is connected and fixed to the hanger portion 11i.

[0109] The push plate 43a can press the driving side variable pulley 33 via an annular thrust bearing 36 and an annular thrust washer 37. The thrust bearing 36 supports the rotating driving side variable pulley 33 so that the driving side variable pulley 33 can rotate in the second direction (axial direction).

[0110] In the above-described embodiment, the pair of cam followers 43b, 43c are used as the follower, but instead of the cam followers, a rod-shaped member may be used as the follower.

[0111] (Speed-change drive device) The speed-change drive device 44 is a device that drives the cam 41 a to relatively move the drive-side variable pulley 33. The speed-change drive device 44 includes a motor (hereinafter, sometimes referred to as a speed-change motor) 44 a, which is a speed-change drive source, a shift shaft 44 b, a coupling 44 c, and a retainer 44 d.

[0112] The motor 44a is a speed-changing drive source that drives the cam 41a to move the drive-side variable pulley 33 relatively. The motor 44a is a rotary electric motor and has a rotating output shaft 44a1. The output shaft 44a1 is provided to extend along the first direction. As shown in FIG. 1 , the motor 44a is fixed to the side surface of the down tube 11d via a motor bracket 11d1. The motor 44a is formed smaller than the down tube 11d. The width of the motor 44a is formed to be smaller than the width of the down tube 11d.

[0113] A shift shaft 44b is connected to the output shaft 44a1 of the motor 44a via a coupling 44c so as to rotate integrally with the motor 44a. The shift shaft 44b is rod-shaped, arranged coaxially with the output shaft 44a1, and extends in the first direction. The shift shaft 44b is rotatably supported on the side surface of the down tube 11d via a bearing bracket 11d2 (see FIG. 1).

[0114] A retainer 44d is provided on the shift shaft 44b so as to be capable of spirally rotatable relative to the shift shaft 44b. The retainer 44d is cylindrical. One end (lower end) of the retainer 44d is provided with a pair of flanges 44d1, 44d2 that protrude outward. The other end (upper end) of the retainer 44d is provided with a locking groove 44d3. The inner peripheral wall surface of the retainer 44d is provided with a female thread that screws into a male thread formed on the outer peripheral wall surface of the shift shaft 44b.

[0115] A pair of flanges 44d1, 44d2 provided on the retainer 44d are engaged with a pair of engaging recesses (not shown) formed in the through-hole 42a1. As a result, the retainer 44d is fixed in the through-hole 42a1 formed in the base 42a of the cam portion 42 in a state where rotation is restricted and movement in the first direction (upward) is restricted. Furthermore, a C-shaped engaging member 44e (e.g., a circlip) is detachably fixed to the engaging groove 44d3 of the retainer 44d. As a result, the retainer 44d is fixed in a state where movement in the first direction (downward) is restricted, and therefore the retainer 44d is fixed to the base 42a of the cam portion 42 in a state where movement along the first direction is restricted.

[0116] The shift shaft 44b and the retainer 44d constitute a feed screw 45. When the output shaft 44a1 of the motor 44a rotates in a first rotational direction RD1 (see FIGS. 5A and 5B ) and the shift shaft 44b rotates in the first rotational direction RD1, the retainer 44d moves (advances) diagonally downward and rearward in the first direction, and the cam portion 42 moves (advances) diagonally downward and rearward in the first direction. On the other hand, when the output shaft 44a1 of the motor 44a rotates in a second rotational direction RD2 (see FIGS. 5A and 5B ), which is the opposite rotational direction to the first rotational direction RD1, and the shift shaft 44b rotates in the second rotational direction RD2, the retainer 44d moves (retreats) diagonally upward and forward in the first direction, and the cam portion 42 moves (retreats) diagonally upward and frontward in the first direction. The first rotation direction RD1 is the clockwise direction when the motor 44a is viewed from the shift rake 42 side in FIGS. 5A and 5B, and the second rotation direction RD2 is the counterclockwise direction.

[0117] Although the feed screw 45 is configured as a sliding screw having a screw shaft and a nut, it may be configured as a ball screw having a screw shaft, a nut, and balls.

[0118] Incidentally, the speed change drive device 44 employs a rotary motor 44a as the speed change drive source and employs a feed screw 45 to convert the rotational motion of the output shaft 44a1 into linear motion of the retainer 44d and ultimately the cam portion 42. However, a linear motor may be employed as the speed change drive source, and the linear motion of the output shaft of the linear motor may directly cause linear motion of the cam portion 42. In this case, the retainer 44d may be omitted, and the output shaft of the linear motor may be connected to the cam portion 42 via a shift shaft 44b that has no threaded portion.

[0119] (Driven part) As shown in FIG. 10 , the driven part 23b (50) mainly includes a driven pulley 51, a sliding sleeve 54, a first driven slide bush 55, a second driven slide bush 56, a tension maintaining part 57, a cassette free 58, and a mounting bolt 59.

[0120] (Driven Pulley) The driven pulley 51 is provided on the axle 14c (driven shaft) driven by the crankshaft 21a. The driven pulley 51 has a driven fixed pulley 52, which is the fixed pulley of the driven pulley 51, and a driven variable pulley 53, which is the variable pulley of the driven pulley 51. The driven fixed pulley 52 is fitted and fixed via a first driven slide bush 55 to the other end (left end) of a sliding sleeve 54, which is attached to the hub 14a2 of the rear wheel 14 via a cassette free 58 so as to be integrally rotatable. The driven variable pulley 53 is attached to the sliding sleeve 54 via a second driven slide bush 56, which is slidable along the axial direction of the sliding sleeve 54 but whose rotation about the axis is restricted.

[0121] (Follower-side fixed pulley) As shown in Figures 11A to 11C, the driven-side fixed pulley 52 is formed in a substantially conical disk shape, and has a pulley body 52a formed in a conical disk shape, and a stepped through hole 52c formed in the center coaxially with the pulley body 52a.

[0122] The pulley body 52a has a conical surface 52a1 and a bottom surface 52a2, which are friction surfaces. Concave portions 52d and convex portions 52e, each of which is formed in a roughly fan-like shape when viewed from the right side (when viewed from above in FIG. 11A ), are alternately formed along the circumferential direction on the conical surface 52a1. A plurality of the concave portions 52d are formed along the circumferential direction at a predetermined angle α2. The apex angle of the concave portions 52d is set to a predetermined angle α1. A plurality of the convex portions 52e are formed along the circumferential direction at a predetermined angle α1. The apex angle of the convex portions 52e is set to a predetermined angle α2. The predetermined angle α1 and the predetermined angle α2 are set to the same value.

[0123] (Recess) As shown in FIG. 11C, recess 52d opens to the right, and as shown in FIG. 11A, the outer peripheral end of recess 52d extends to the inner circumference of conical outer annular portion 52a3 having a predetermined width, and the inner peripheral end of recess 52d extends to the inner circumference of large diameter hole portion 52c1 (the outer peripheral wall surface of inner cylindrical portion 52f).

[0124] As shown in FIGS. 11A to 11C, the recess 52d has an inner peripheral wall surface 52d1, an outer peripheral wall surface 52d2, a first side wall surface 52d3, a second side wall surface 52d4, a bottom surface 52d5, and an opening 52d6.

[0125] 11A, the inner peripheral wall surface 52d1 is an outer peripheral wall surface formed on the inner cylindrical portion 52f at a predetermined angle α1 and spaced a predetermined distance from the inner cylindrical portion 52f. As shown in FIG. 11C, the inner peripheral wall surface 52d1 is formed in the axial direction (the axial direction of the driven-side fixed pulley 52) from a right end surface 52f1, which is one end surface of the inner cylindrical portion 52f, to a bottom surface 52d5.

[0126] As shown in Fig. 11A, the outer peripheral wall surface 52d2 is an inner peripheral wall surface formed at a predetermined angle α1 and a predetermined distance (predetermined angle α2) from the conical outer annular portion 52a3. As shown in Fig. 11C, the outer peripheral wall surface 52d2 is formed in the axial direction from the conical surface 52a1 to the bottom surface 52a2.

[0127] As shown in Fig. 11A, the first side wall surface 52d3 extends radially from the pulley body 52a. The first side wall surface 52d3 is formed radially from the inner circumferential wall surface 52d1 to the outer circumferential wall surface 52d2. As shown in Fig. 11C, the first side wall surface 52d3 is formed axially from the conical surface 52a1 to the bottom surface 52d5 or the bottom surface 52a2.

[0128] As shown in FIG. 11A, the second side wall surface 52d4 extends radially of the pulley body 52a. The second side wall surface 52d4 faces the first side wall surface 52d3 and is disposed at a predetermined angle α1. The second side wall surface 52d4 extends radially (in the radial direction of the driven-side fixed pulley 52) from the inner circumferential wall surface 52d1 to the outer circumferential wall surface 52d2. As shown in FIG. 11C, the second side wall surface 52d4 extends axially from the conical surface 52a1 to the bottom surface 52d5 or the bottom surface 52a2.

[0129] An opening 52d6 that is U-shaped and opens radially inward is provided between the inner end of the first side wall surface 52d3, the inner end of the second side wall surface 52d4, and the left end of the inner wall surface 52d1 (the outer peripheral end of the right end surface 52f1 of the inner cylindrical portion 52f).

[0130] As shown in FIG. 11A , the bottom surface 52d5 connects the first side wall surface 52d3 and the second side wall surface 52d4. The bottom surface 52d5 extends radially outward from the inner circumferential wall surface 52d1 (the radial direction of the driven-side fixed pulley 52). The outer peripheral edge of the bottom surface 52d5 is open, and a space (opening) 52d7 is formed between the bottom surface 52d5 and the outer circumferential wall surface 52d2. The bottom surface 52d5 is annular and inclined.

[0131] As shown in FIG. 11C, the bottom surface 52d5 of the recess 52d is an inclined surface that tapers outward. A recess 52h corresponding to the top of the meshing protrusion 53e (see FIG. 11E) is formed on the bottom surface 52d5 to allow the top of the protrusion 53e to escape when the meshing protrusion 53e enters the recess 52d. The depth and inclination of the recess 52h are set within a range that prevents the recess 52h from reaching the bottom surface 52a2, and the depth is preferably set to a value that allows the top of the protrusion 53e to enter as far as possible. The bottom surface 52d5 is also formed parallel to the third sidewall surface (upper wall surface) 53e5, which is the friction surface 53a1 of the protrusion 53e. This allows the strength of the bottom side of the recess 52d, and therefore the strength of the driven side fixed pulley 52, to be maintained high by leaving the thickness from the bottom surface 52d5 (relief portion 52h) of the recess 52d to the bottom surface 52a2, and when the driven side variable pulley 53 and the driven side fixed pulley 52 are closed, the top of the protrusion 53e enters the relief portion 52h, so the thickness of the driven side pulley 51 in the closed state (see Figure 5A) can be kept small.

[0132] (Convex portion) As shown in FIG. 11C, the convex portion 52e protrudes toward the right, and the outer peripheral end of the convex portion 52e extends to the inner circumference of the conical outer annular portion 52a3 having a predetermined width, and the inner peripheral end of the convex portion 52e extends to the inner circumference of the large diameter hole portion 52c1 (an extension line of the outer peripheral wall surface of the inner cylindrical portion 52f).

[0133] As shown in FIGS. 11A to 11C, the protrusion 52e has an inner peripheral wall surface 52e1, a first side wall surface 52e3, a second side wall surface 52e4, a third side wall surface (upper wall surface) 52e5, and a fourth side wall surface (lower side surface) 52e6.

[0134] As shown in Fig. 11A, the inner peripheral wall surface 52e1 is an inner peripheral wall surface formed on the protrusion 52e at a predetermined angle α2. As shown in Fig. 11C, the inner peripheral wall surface 52e1 is provided in the axial direction (the axial direction of the driven-side fixed pulley 52) from the conical surface 52a1 to a bottom surface 52d5 of the recess 52d. The left half of the inner peripheral wall surface 52e1 (the portion to the left of a right end surface 52f1, which is one end surface of the inner cylindrical portion 52f) is integrally connected to the outer peripheral wall surface of the inner cylindrical portion 52f.

[0135] As shown in Fig. 11A, the first side wall surface 52e3 extends radially from the pulley body 52a. The first side wall surface 52e3 extends radially from the inner peripheral wall surface 52e1 and the inner peripheral wall surface 52d1 to the outer peripheral wall surface 52d2. As shown in Fig. 11C, the first side wall surface 52e3 extends axially from the conical surface 52a1 to the bottom surface 52d5 or the bottom surface 52a2. The first side wall surface 52e3 is identical to the second side wall surface 52d4 of the recess 52d.

[0136] As shown in FIG. 11A, the second side wall surface 52e4 extends radially of the pulley body 52a. The second side wall surface 52e4 is disposed on the side opposite the first side wall surface 52e3 and at a predetermined angle α2. The second side wall surface 52e4 extends radially from the inner peripheral wall surface 52e1 and the inner peripheral wall surface 52d1 to the outer peripheral wall surface 52d2. As shown in FIG. 11C, the second side wall surface 52e4 extends axially from the conical surface 52a1 to the bottom surface 52d5 or the bottom surface 52a2. The second side wall surface 52e4 is identical to the first side wall surface 52d3 of the recess 52d.

[0137] The third side wall surface (upper wall surface) 52e5 connects one end edge (right edge) of the first side wall surface 52e3 to one end edge (right edge) of the second side wall surface 52e4. The fourth side wall surface (lower surface) 52e6 connects the other end edge (left edge) of the first side wall surface 52e3 to the other end edge (left edge) of the second side wall surface 52e4.

[0138] The through hole 52c has a large diameter hole portion 52c1 and a small diameter hole portion 52c2 that is smaller in diameter than the large diameter hole portion 52c1. The large diameter hole portion 52c1 and the small diameter hole portion 52c2 are provided in this order from right to left as shown in FIG. 11C.

[0139] Specifically, the through hole 52c is provided with an inner tube portion 52f formed in a substantially cylindrical shape, with one end surface 52f1 (right end surface 52f1) of the inner tube portion 52f located in the left-right center of the inner circumferential wall surface 52e1 of the convex portion 52e. The other end surface 52f2 (left end surface 52f2) of the inner tube portion 52f is formed flush with the bottom surface 52a2. As shown in FIGS. 11A to 11C , an annular flange portion 52f4 is formed at the other end (left end) of the inner tube portion 52f, protruding radially outward. The annular flange portion 52f4 is formed so that its thickness increases toward the outer periphery of the recess 52d. The left side surface of the annular flange portion 52f4 is flush with the bottom surface 52a2, while the right side surface of the annular flange portion 52f4 is an inclined surface that forms a predetermined angle with respect to the bottom surface 52a2 and forms the bottom surface 52d5 of the recess 52d. An inner peripheral wall surface 52e1 of each protrusion 52e forms a large diameter hole portion 52c1, and an inner peripheral wall surface of the inner cylindrical portion 52f forms a small diameter hole portion 52c2.

[0140] A plurality of arc-shaped recesses 52f3 (six in this embodiment) are provided at a predetermined interval along the circumferential direction at the right end of the inner peripheral wall surface of the inner cylindrical portion 52f. The recesses 52f3 are engaged with the engaging protrusions 55a of the first driven-side slide bush 55, and the driven-side fixed pulley 52 is fixed to the first driven-side slide bush 55. The driven-side fixed pulley 52 is fixed to the first driven-side slide bush 55 while being restricted from rotating and from moving axially leftward.

[0141] (Followered-Side Variable Pulley) The driven-side variable pulley 53 is configured in the same manner as the driven-side fixed pulley 52. ​​As shown in Figures 11D and 11E, the driven-side variable pulley 53 is formed in a substantially conical disk shape, and has a pulley body 53a formed in a conical disk shape, and a stepped through-hole 53c formed in the center coaxially with the pulley body 53a.

[0142] The pulley body 53a has a conical surface 53a1, which is a friction surface, and a bottom surface 53a2. Concave portions 53d and convex portions 53e, each formed in a roughly fan shape, are alternately formed along the circumferential direction on the conical surface 53a1. A plurality of concave portions 53d are formed along the circumferential direction at a predetermined angle α2. The apex angle of the concave portions 53d is set to a predetermined angle α1. A plurality of convex portions 53e are formed along the circumferential direction at a predetermined angle α1. The apex angle of the convex portions 53e is set to a predetermined angle α2. The predetermined angle α1 and the predetermined angle α2 are set to the same value.

[0143] (Recess) As shown in FIG. 11E, recess 53d is open to the left, and as shown in FIG. 11D, the outer peripheral end of recess 53d extends to the inner circumference of conical outer annular portion 53a3 having a predetermined width, and the inner peripheral end of recess 53d extends to the inner circumference of large diameter hole portion 53c1.

[0144] As shown in FIGS. 11D and 11E, the recess 53d has an inner peripheral wall surface 53d1, an outer peripheral wall surface 53d2, a first side wall surface 53d3, a second side wall surface 53d4, a bottom surface 53d5, and an opening 53d6.

[0145] The inner peripheral wall surface 53d1 is an outer peripheral wall surface formed on the inner cylindrical portion 53f at a predetermined angle α1 and spaced a predetermined distance from the inner cylindrical portion 53f. As shown in FIG. 11E, the inner peripheral wall surface 53d1 extends from a left end surface 53f1, which is the other end surface of the inner cylindrical portion 53f, to a bottom surface 53d5 in the axial direction (the axial direction of the driven-side variable pulley 53).

[0146] As shown in Fig. 11D, the outer peripheral wall surface 53d2 is an inner peripheral wall surface formed at a predetermined angle α1 and a predetermined distance (predetermined angle α2) from the conical outer annular portion 53a3. As shown in Fig. 11E, the outer peripheral wall surface 53d2 is formed in the axial direction from the conical surface 53a1 to the bottom surface 53a2.

[0147] As shown in Fig. 11D, the first side wall surface 53d3 extends radially from the inner peripheral wall surface of the large-diameter hole portion 53c1 to the outer peripheral wall surface 53d2. As shown in Fig. 11E, the first side wall surface 53d3 extends axially from the conical surface 53a1 to the bottom surface 53d5 and the bottom surface 53a2.

[0148] As shown in Fig. 11D, the second side wall surface 53d4 extends radially of the pulley body 53a. The second side wall surface 53d4 faces the first side wall surface 53d3 and is disposed at a predetermined angle α1. The second side wall surface 53d4 extends radially (in the radial direction of the driven variable pulley 53) from the inner peripheral wall surface of the large diameter hole portion 53c1 to the outer peripheral wall surface 53d2. As shown in Fig. 11E, the second side wall surface 53d4 extends axially from the conical surface 53a1 to the bottom surface 53d5 and bottom surface 53a2.

[0149] An opening 53d6 formed in a U-shape and opening radially inward is provided between the inner end of the first side wall surface 53d3, the inner end of the second side wall surface 53d4, and the outer peripheral end of the left end surface 53f1 of the inner cylindrical portion 53f.

[0150] As shown in FIG. 11D , the bottom surface 53d5 connects the first side wall surface 53d3 and the second side wall surface 53d4. As shown in FIG. 11E , the bottom surface 53d5 extends radially (in the radial direction of the driven-side variable pulley 53) outward from the outer circumferential end (the inner circumferential wall surface 53d1 of the recess 53d) of the right end surface 53f2 of the inner cylindrical portion 53f. The bottom surface 53d5 has an annular, inclined surface. The outer circumferential edge of the bottom surface 53d5 is open, and a space (opening) 53d7 is formed between the outer circumferential wall surface 53d2 and the bottom surface 53d5.

[0151] As shown in FIG. 11E, the bottom surface 53d5 of the recess 53d is an inclined surface that tapers outward. A recess 53h corresponding to the top of the engaging protrusion 52e (see FIG. 11C) is formed on the bottom surface 53d5 to allow the top of the protrusion 52e to escape when the engaging protrusion 52e enters the recess 53d. The depth and inclination of the recess 53h are set within a range that prevents the recess 53h from reaching the bottom surface 53a2, and the depth is preferably set to a value that allows the top of the protrusion 52e to enter as far as possible. The bottom surface 53d5 is also formed parallel to the third sidewall surface (upper wall surface) 52e5, which is the friction surface 52a1 of the protrusion 52e. This allows the strength of the bottom side of the recess 53d, and therefore the strength of the driven side variable pulley 53, to be maintained high by leaving the thickness from the bottom surface 53d5 (relief portion 53h) of the recess 53d to the bottom surface 53a2, and when the driven side variable pulley 53 and the driven side fixed pulley 52 are closed, the top of the protrusion 52e enters the relief portion 53h, so the thickness of the driven side pulley 51 in the closed state (see Figure 5A) can be kept small.

[0152] (Convex portion) As shown in FIG. 11E, the convex portion 53e protrudes toward the left, and the outer peripheral end of the convex portion 53e extends to the inner circumference of the conical outer annular portion 53a3 having a predetermined width, and the inner peripheral end of the convex portion 53e extends to the inner circumference of the large diameter hole portion 53c1.

[0153] As shown in Figures 11D and 11E, the convex portion 53e has an inner wall surface 53e1, a first side wall surface 53e3, a second side wall surface 53e4, a third side wall surface (upper wall surface) 53e5, and a fourth side wall surface (lower side surface) 53e6.

[0154] As shown in Fig. 11D, the inner peripheral wall surface 53e1 is an inner peripheral wall surface formed at a predetermined angle α2 on the protrusion 53e. As shown in Fig. 11E, the inner peripheral wall surface 53e1 is provided in the axial direction (the axial direction of the driven-side fixed pulley 52) from the conical surface 53a1 to the bottom surface 53d5 of the recess 53d. The right half of the inner peripheral wall surface 53e1 (the portion to the right of the left end surface 53f1, which is the other end surface of the inner cylindrical portion 53f) is integrally connected to the outer peripheral wall surface of the inner cylindrical portion 53f.

[0155] As shown in Fig. 11D, the first side wall surface 53e3 extends radially from the pulley body 53a. The first side wall surface 53e3 is formed radially from the inner circumferential wall surface 53e1 to the outer circumferential wall surface 53d2. As shown in Fig. 11E, the first side wall surface 53e3 is formed axially from the conical surface 53a1 to the bottom surface 52d5 or the bottom surface 53a2. The first side wall surface 53e3 is identical to the second side wall surface 53d4 of the recess 53d.

[0156] As shown in FIG. 11D, the second side wall surface 53e4 extends radially of the pulley body 53a. The second side wall surface 53e4 is disposed on the side opposite the first side wall surface 53e3 and at a predetermined angle α2. The second side wall surface 53e4 extends radially from the inner circumferential wall surface 53e1 to the outer circumferential wall surface 53d2 (see FIG. 11E). As shown in FIG. 11E, the second side wall surface 53e4 extends axially to the bottom surface 52d5 or the bottom surface 53a2. The second side wall surface 53e4 is identical to the first side wall surface 53d3 of the recess 53d.

[0157] The third side wall surface (upper wall surface) 53e5 connects the other end edge (left edge) of the first side wall surface 53e3 to the other end edge (left edge) of the second side wall surface 53e4. The fourth side wall surface (lower surface) 53e6 connects one end edge (right edge) of the first side wall surface 53e3 to one end edge (right edge) of the second side wall surface 53e4.

[0158] The through hole 53c has a large diameter hole portion 53c1 and a small diameter hole portion 33c2 having a diameter smaller than that of the large diameter hole portion 53c1. The large diameter hole portion 53c1 and the small diameter hole portion 33c2 are provided in this order from left to right as shown in FIG. 11E.

[0159] Specifically, a generally cylindrical inner tube portion 53f is provided in the through hole 53c, and the other end surface 53f1 (left end surface 53f1) of the inner tube portion 53f is located in the left-right center of the inner circumferential wall surface 53e1 of the protrusion 53e. One end surface 53f2 (right end surface 53f2) of the inner tube portion 53f is flush with the bottom surface 53a2. One end surface 53f2 of the inner tube portion 53f is provided with an annular groove 53f5 formed concentrically outside the through hole 53c. One end of the coil spring 57a is engaged in the annular groove 53f5.

[0160] As shown in Figures 11D and 11E, an annular flange 53f4 is formed at one end (right end) of the inner cylindrical portion 53f so as to protrude radially outward. The annular flange 53f4 is formed so as to become thicker toward the outer periphery of the recess 53d. The right side of the annular flange 53f4 is flush with the bottom surface 53a2, while the left side of the annular flange 53f4 is an inclined surface that forms a predetermined angle with the bottom surface 53a2 and forms the bottom surface 53d5 of the recess 53d. The inner peripheral wall surface 53e1 of each protrusion 53e defines the large-diameter hole 53c1, and the inner peripheral wall surface of the inner cylindrical portion 53f defines the small-diameter hole 53c2.

[0161] A plurality of arc-shaped recesses 53f3 (six in this embodiment) are provided at predetermined intervals along the circumferential direction at the left end of the inner peripheral wall surface of the inner cylindrical portion 53f. The recesses 53f3 are engaged with the engaging protrusions 56a of the second driven-side slide bush 56, and the driven-side variable pulley 53 is fixed to the second driven-side slide bush 56. The driven-side variable pulley 53 is fixed to the second driven-side slide bush 56 while being restricted from rotating and from moving axially leftward.

[0162] (Sliding sleeve / slide bush) The sliding sleeve 54 is formed in a cylindrical shape, as shown in Figure 10, and serves to rotate and fix the driven side fixed pulley 52 and the driven side variable pulley 53 together, and to support the driven side variable pulley 53 so that it can slide in the axial direction of the sliding sleeve 54.

[0163] The driven-side fixed pulley 52 is fixed to the outer peripheral surface of the left end of the sliding sleeve 54 via a first driven-side slide bush 55 so as to rotate integrally therewith.

[0164] A plurality of (nine in this embodiment) engaging grooves 54a are provided on the outer peripheral wall surface of the sliding sleeve 54 at predetermined intervals along the circumferential direction of the sliding sleeve 54, and the ridges 55b of the first driven-side slide bush 55 are guided and engaged with the engaging grooves 54a. A plurality of (nine in this embodiment) engaging grooves 54b are provided on the inner peripheral wall surface of the sliding sleeve 54 at predetermined intervals along the circumferential direction of the sliding sleeve 54, and the ridges 58a of the cassette free 58 are guided and engaged with the engaging grooves 54a.

[0165] An outwardly protruding annular flange portion 54c is formed at the other end (left end) of the sliding sleeve 54. The annular flange portion 54c comes into contact with the peripheral edge of the through-hole 52c in the bottom surface 52a2 of the driven-side fixed pulley 52, thereby positioning and fixing the driven-side fixed pulley 52 to the sliding sleeve 54 in the axial direction. An annular groove 54d is formed at the other end (left end) of the outer peripheral wall surface of the sliding sleeve 54, at a position spaced apart from the other end by the thickness of the driven-side fixed pulley 52. ​​A ring-shaped circlip 54e is attached to the annular groove 54d. This prevents the driven-side fixed pulley 52 from coming off the sliding sleeve 54 and also fixes the driven-side fixed pulley 52 in the axial direction.

[0166] As shown in FIG. 10 , the first driven-side slide bush 55 is primarily cylindrical and is fitted and fixed within the driven-side fixed pulley 52 to allow the driven-side fixed pulley 52 to slide smoothly onto the sliding sleeve 54 and then position and fix it. An engaging protrusion 55a is provided along the circumferential direction on the outer peripheral wall surface of the first driven-side slide bush 55, corresponding to the recess 52f3 of the driven-side fixed pulley 52. ​​The recess 52f3 of the driven-side fixed pulley 52 is fitted into and fixed to the engaging protrusion 55a. A ridge 55b that protrudes inward is formed along the axial direction on the inner peripheral wall surface of the first driven-side slide bush 55. The ridge 55b slidably engages with the engaging groove 54a of the sliding sleeve 54 along the axial direction.

[0167] Furthermore, the driven variable pulley 53 is supported on the outer peripheral surface of the sliding sleeve 54 via a second driven slide bush 56 so as to be rotatable integrally with the sliding sleeve 54 and slidable in the axial direction.

[0168] As shown in FIG. 10 , the second driven-side slide bush 56 is primarily cylindrical and is fitted and fixed in the driven-side variable pulley 53 to allow the driven-side variable pulley 53 to slide smoothly on the sliding sleeve 54. An engaging protrusion 56a is provided along the circumferential direction on the outer peripheral wall surface of the second driven-side slide bush 56, corresponding to the recess 53f3 of the driven-side variable pulley 53. The recess 53f3 of the driven-side variable pulley 53 is fitted into and fixed to the engaging protrusion 56a. A ridge 56b that protrudes inward is formed along the axial direction on the inner peripheral wall surface of the second driven-side slide bush 56. The ridge 56b slidably engages with the engaging groove 54a of the sliding sleeve 54 along the axial direction.

[0169] (Tension Maintaining Unit) The tension maintaining unit 57 maintains the tension of the V-belt 23c (power transmission member) by moving the driven variable pulley 53 relative to the driven fixed pulley 52 along the axial direction of the axle 14c, which is the driven shaft. The tension maintaining unit 57 has a coil spring 57a, which is a biasing member that biases the driven variable pulley 53 toward the driven fixed pulley 52, and a retainer spring 57b to which the other end of the coil spring 57a is engaged. Note that it is also possible to use another biasing member (for example, a member made of an elastic material) instead of the coil spring 57a.

[0170] The inner diameter of the coil spring 57a is set to be larger than the inner diameter of the through hole 57b2 of the retainer spring 57b and smaller than the outer diameter of the retainer spring 57b. One end of the coil spring 57a is engaged with the driven variable pulley 53, and the other end of the coil spring 57a is engaged with the retainer spring 57b.

[0171] The retainer spring 57b is formed in a generally annular disk shape and has an annular disk portion 57b1, a through hole 57b2 formed in the center of the annular disk portion 57b1, and an annular protrusion 57b3 formed on the outer periphery of the annular disk portion 57b1. The peripheral edge of the through hole 57b2 in the annular disk portion 57b1 of the retainer spring 57b is formed so as to be able to abut against the large diameter portion 59a of the mounting bolt 59. The outer periphery of the annular disk portion 57b1 of the retainer spring 57b is formed so as to be able to abut against the other end of the coil spring 57a.

[0172] (Mounting Bolt - Cassette Free) The cassette free 58 is formed in a cylindrical shape, and a plurality of ridges 58a are formed at predetermined intervals in the circumferential direction and are provided axially on the outer peripheral wall surface of the cassette free 58. The ridges 58a slidably engage with engagement grooves 54b provided on the inner peripheral wall surface of the sliding sleeve 54. As a result, the cassette free 58 is restricted from rotating about its axis by the sliding sleeve 54, and rotates integrally with the sliding sleeve 54, and therefore with the driven variable pulley 53 and the driven fixed pulley 52.

[0173] An annular flange portion 58b extending circumferentially outward is provided at the other outer peripheral end (left outer peripheral end) of the cassette free 58. One end face (right end face) of the annular flange portion 58b contacts the other end face (left end face) of the sliding sleeve 54, thereby positioning and fixing the cassette free 58 in contact with the sliding sleeve 54.

[0174] A through hole 58c is provided in the center of the cassette freewheel 58. An internal thread (not shown) is formed in the other end of the inner circumferential wall of the through hole 58c, to which the hub 14a2 of the rear wheel 14 is screwed. This allows the cassette freewheel 58 to be assembled so as to rotate integrally with the hub 14a2. An internal thread (not shown) is formed in the other end of the inner circumferential wall of the through hole 58c, to which a mounting bolt 59 is screwed. This allows the mounting bolt 59 to be screwed to the cassette freewheel 58, attaching the sliding sleeve 54 onto the cassette freewheel 58 so as to rotate integrally therewith, and further attaching the driven variable pulley 53 and the driven fixed pulley 52 onto the sliding sleeve 54 so as to rotate integrally therewith.

[0175] The cassette freewheel 58 incorporates a one-way clutch (not shown), which is a clutch mechanism that transmits rotational force in only one direction, and the cassette freewheel 58 is attached to the rear wheel axle 14c via the one-way clutch. In order for the cassette freewheel 58 to rotate relatively clockwise in FIG. 1, the one-way clutch causes the cassette freewheel 58 to mesh with the rear wheel axle 14c, through which the cassette freewheel 58 is inserted, and the rotational force of the driven pulley 51 is transmitted to the rear wheel axle 14c. On the other hand, in order for the cassette freewheel 58 to rotate relatively counterclockwise in FIG. 1, the one-way clutch disengages the cassette freewheel 58 from the rear wheel axle 14c, and the rotational force of the driven pulley 51 is not transmitted to the rear wheel axle 14c.

[0176] The rear wheel axle 14c is inserted through the through hole 58c of the cassette freewheel 58 and the through hole 59d of the mounting bolt 59, and a nut (not shown) is screwed onto the right end of the rear wheel axle 14c, so that the cassette freewheel 58, with the driven pulley 51 attached so as to rotate integrally with it, can be fixed to the rear wheel axle 14c.

[0177] The mounting bolt 59 is formed in a stepped cylindrical shape and is provided, in order from the other end (right end), with a large-diameter portion 59a, a medium-diameter portion 59b that is smaller in diameter than the large-diameter portion 59a, a small-diameter portion 59c that is smaller in diameter than the medium-diameter portion 59b, and a through-hole 59d. The large-diameter portion 59a is abutted by the annular disk portion 57b1 of the retainer spring 57b, and the coil spring 57a abutting against the retainer spring 57b biases the driven-side variable pulley 53. The outer peripheral wall surface of the small-diameter portion 59c is formed with a male thread (not shown) that screws into a female thread (not shown) in a through-hole 58c of the cassette freewheel 58, and the mounting bolt 59 is screwed to the cassette freewheel 58. The rear wheel axle 14c can be inserted into the through-hole 59d.

[0178] (V-Belt) The V-belt 23c is a power transmission member that is mounted on the drive pulley 31 and the driven pulley 51 and transmits human power (external force) applied to the crankshaft 21a, which is the drive shaft, to the rear wheel shaft 14c, which is the driven shaft. The V-belt 23c is a type of belt drive (rotary power transmission mechanism) that uses frictional force to transmit power (frictional transmission), and is formed in an inverted trapezoidal shape (V-shape) in which the outer periphery of the belt cross section is wider and the inner periphery is narrower. The V-belt 23c generates a stronger frictional force than a flat belt of the same width due to the large contact area and wedge action of the V-shape.

[0179] 5A, one side of the V-belt 23c contacts the friction surface 32a1 of the drive-side fixed pulley 32, and the other side of the V-belt 23c contacts the friction surface 33a1 of the drive-side variable pulley 33. As shown in FIG. 5B, one side of the V-belt 23c contacts the friction surface 53a1 of the driven-side variable pulley 53, and the other side of the V-belt 23c contacts the friction surface 52a1 of the driven-side fixed pulley 52.

[0180] (Operation of Continuously Variable Transmission) (Low Gear) Low gear is a speed change state in which the gear ratio is reduced by making the inner diameter of the V-belt 23c wound around the driven pulley 51 larger than the inner diameter of the V-belt 23c wound around the drive pulley 31. At this time, the output torque of the rear wheel 14 is increased, and the distance traveled per rotation of the crank 21 is reduced. On the other hand, high gear is a speed change state in which the gear ratio is increased by making the inner diameter of the V-belt 23c wound around the driven pulley 51 smaller than the inner diameter of the V-belt 23c wound around the drive pulley 31. At this time, the output torque of the rear wheel 14 is reduced, and the distance traveled per rotation of the crank 21 is increased.

[0181] 5A , when the shift rake (cam portion) 42 is in the reverse position, the push plate 43a, which is in contact with the shift rake 42 via the cam followers 43b and 43c, and therefore the drive-side variable pulley 33, are in their outermost positions, and the drive-side pulley 31 is in an open state (maximum open state). At this time, the V-belt 23c wound around the drive-side pulley 31 is pulled by the driven pulley 51, pressing the drive-side variable pulley 33 outward and generating a friction force between the friction surface 33a1 of the drive-side variable pulley 33 and the friction surface 32a1 of the drive-side fixed pulley 32. The inner diameter of the V-belt 23c wound around the drive-side pulley 31 is the minimum diameter.

[0182] In the driven pulley 51, the driven variable pulley 53 is constantly urged toward the driven fixed pulley 52 by the coil spring 57a of the tension maintaining unit 57. Therefore, the V-belt 23c of the driven pulley 51 is moved outward so that its inner diameter increases, and the V-belt 23c is pulled by the driven pulley 51. At this time, the driven variable pulley 53 is in its innermost position, and the driven pulley 51 is in a closed state (a state where it is least open). The inner diameter of the V-belt 23c wound around the driven pulley 51 is at its maximum.

[0183] When the output shaft 44a1 of the motor 44a is rotated in the second rotational direction RD2, the shift rake 42 moves backward to the reverse position, and the continuously variable transmission 23 can shift to the low gear shown in Fig. 5A. The V-belt 23c wound around the drive pulley 31 is constantly pulled by the driven pulley 51 by the tension maintaining unit 57 (coil spring 57a). Therefore, the tension of the V-belt 23c is maintained constant even when the shift rake 42 is moving backward, and the drive variable pulley 33 is moved to the outermost position, and the inner diameter of the V-belt 23c wound around the drive pulley 31 becomes the smallest diameter.

[0184] (High Gear) In high gear, as shown in Figures 5B and 6B, when the shift rake (cam portion) 42 is in the forward position, the push plate 43a, which is in contact with the shift rake 42 via the cam followers 43b and 43c, and therefore the drive-side variable pulley 33, are in their innermost positions, and the drive-side pulley 31 is in a closed state. When the drive-side variable pulley 33, which is in low gear, is moved toward the drive-side fixed pulley 32 by the push plate 43a, the drive-side variable pulley 33 is moved inward, which expands the inner diameter of the V-belt 23c of the drive-side pulley 31, and the V-belt 23c is pulled toward the drive-side pulley 31. At this time, the drive-side variable pulley 33 is in its innermost position, and the drive-side pulley 31 is in a closed state. The inner diameter of the V-belt 23c wrapped around the drive-side pulley 31 is at its maximum.

[0185] In the driven pulley 51, the V-belt 23c is pulled by the drive pulley 31, so the driven variable pulley 53 is moved in a direction away from the driven fixed pulley 52 (outward) against the biasing force of the coil spring 57a of the tension maintaining unit 57. Therefore, the V-belt 23c of the driven pulley 51 is moved so that its inner diameter decreases. At this time, the driven variable pulley 53 is in the outermost position, and the driven pulley 51 is in an open state. The inner diameter of the V-belt 23c wound around the driven pulley 51 is at its minimum.

[0186] When the output shaft 44a1 of the motor 44a is rotated in the first rotational direction RD1, the shift rake 42 moves forward to the forward position, and the continuously variable transmission 23 can shift to the high gear shown in Fig. 5B. The V-belt 23c wound around the drive pulley 31 is constantly pulled by the driven pulley 51 by the tension maintaining unit 57 (coil spring 57a). Therefore, the tension of the V-belt 23c is maintained constant even while the shift rake 42 is moving forward, and the drive variable pulley 33 is moved to the innermost position, and the inner diameter of the V-belt 23c wound around the drive pulley 31 becomes the maximum diameter.

[0187] (Drive Assist Unit) As shown in FIG. 7, the drive assist unit 16 includes an assist motor 16a, an assist drive gear 16b, an assist driven gear 16c, and a drive belt 16d. The assist motor 16a is an assist drive source that assists human power. The assist motor 16a can directly drive the crankshaft 21a, which is the drive shaft. (Or, it can directly drive the wheels of the human-powered vehicle.) The assist motor 16a is fixed to a mounting bracket (not shown) fixed to the frame 11. An assist drive gear 16b is provided on the output shaft 16a1 of the assist motor 16a so as to rotate integrally with it. The assist driven gear 16c is assembled to the crankshaft 21a so as to rotate integrally with it (see FIGS. 6A and 6B). A drive belt 16d is fitted between the assist drive gear 16b and the assist driven gear 16c, allowing the driving force of the assist motor 16a to be transmitted to the assist driven gear 16c.

[0188] 12, the control device 17 is connected to an operating device 17c that is operated by the rider, a bicycle speed sensor 17d that detects the speed of the bicycle 10, a torque sensor 17e that detects the torque applied to the crankshaft 21a (pedal torque applied by the rider), the gear shift motor 44a, the assist motor 16a, and a motor driver 17f that controls the charging and discharging of the battery 18 connected to the assist motor 16a. The control device 17 has a microcomputer (not shown), which is equipped with an input / output interface, a CPU, RAM, and ROM (all not shown), which are connected via a bus.

[0189] (Modifications (Drive Pulley, Driven Pulley)) Next, modifications (frictional force improvement) of the above-mentioned drive pulley 31 will be described with reference to Figures 13A to 13F. Note that similar modifications can also be made to the driven pulley 51.

[0190] (Drive Side Pulley) The drive side pulley 131 according to the modified example has a drive side fixed pulley 132 and a drive side variable pulley 133. Like the drive side fixed pulley 32, the drive side fixed pulley 132 is fitted and fixed to one end (the right end) of the center boss 34, and like the drive side variable pulley 33, the drive side variable pulley 133 is attached to the center boss 34 so as to be slidable along the axial direction of the center boss 34 but with its rotation about the axis restricted.

[0191] (Drive side fixed pulley) As shown in Figures 13A to 13C, the drive side fixed pulley 132 is formed in a roughly conical disk shape, and has a pulley body 132a formed in a conical disk shape, a circular protrusion 132b formed coaxially with the pulley body 132a and protruding from the bottom surface 132a2, and a stepped through hole 132c formed in the center coaxially with the pulley body 132a.

[0192] The pulley body 132a has a conical surface 132a1 and a bottom surface 132a2, which are friction surfaces. The conical surface 132a1 has a plurality of recesses 132d and protrusions 132e, each of which is formed in a generally fan-shaped configuration when viewed from the left side in FIG. 13C , alternately arranged along the circumferential direction. A plurality of recesses 132d are arranged along the circumferential direction at a predetermined angle α12. The apex angle of each recess 132d is set to a predetermined angle α11. A plurality of protrusions 132e are arranged along the circumferential direction at a predetermined angle α11. The apex angle of each protrusion 132e is set to a predetermined angle α12. The predetermined angles α11 and α12 are set to the same value. Six recesses 132d and six protrusions 132e are formed, and the predetermined angles α11 and α12 are set to 60 degrees. It is preferable to form an even number of recesses 132d and six protrusions 132e.

[0193] (Recess) As shown in Figure 13C, recess 132d opens to the left, and as shown in Figure 13A, the outer peripheral end of recess 132d extends to the inner circumference of conical outer annular portion 132a3 having a predetermined width, and the inner peripheral end of recess 132d extends to the inner circumference of large diameter hole portion 132c1 (the outer peripheral wall surface of inner cylinder portion 132f).

[0194] As shown in FIGS. 13A to 13C, the recess 132d has an inner peripheral wall surface 132d1, an outer peripheral wall surface 132d2, a first side wall surface 132d3, a second side wall surface 132d4, a bottom surface 132d5, and an opening 132d6.

[0195] As shown in Fig. 13A, the inner peripheral wall surface 132d1 is an outer peripheral wall surface formed on the inner cylindrical portion 132f at a predetermined angle α11 and spaced a predetermined distance from the inner cylindrical portion 132f. As shown in Fig. 13C, the inner peripheral wall surface 132d1 is formed in the axial direction (the axial direction of the drive-side fixed pulley 132) from a left end surface 132f1, which is one end surface of the inner cylindrical portion 132f, to a bottom surface 132d5.

[0196] As shown in Fig. 13A, the outer peripheral wall surface 132d2 is an inner peripheral wall surface formed at a predetermined angle α11 at a predetermined interval (predetermined angle α12) from the conical outer annular portion 132a3. As shown in Fig. 13C, the outer peripheral wall surface 132d2 is formed in the axial direction from the conical surface 132a1 to the bottom surface 132a2.

[0197] As shown in Fig. 13A, the first side wall surface 132d3 extends radially from the pulley body 132a. The first side wall surface 132d3 is formed radially from the inner circumferential wall surface 132d1 to the outer circumferential wall surface 132d2. As shown in Fig. 13C, the first side wall surface 132d3 is formed axially from the conical surface 132a1 to the bottom surface 132d5 or the bottom surface 132a2.

[0198] As shown in FIG. 13A , the second side wall surface 132d4 extends radially from the pulley body 132a. The second side wall surface 132d4 faces the first side wall surface 132d3 and is disposed at a predetermined angle α11. The second side wall surface 132d4 extends radially from the inner circumferential wall surface 132d1 to the outer circumferential wall surface 132d2. The second side wall surface 132d4 extends axially from the conical surface 132a1 to the bottom surface 132d5 or the bottom surface 132a2.

[0199] An opening 132d6 that is U-shaped and opens radially inward is provided between the inner end of the first side wall surface 132d3, the inner end of the second side wall surface 132d4, and the left end of the inner wall surface 132d1 (the outer peripheral end of the left end surface 132f1 of the inner cylindrical portion 132f).

[0200] As shown in FIG. 13A , the bottom surface 132d5 connects the first side wall surface 132d3 and the second side wall surface 132d4. The bottom surface 132d5 extends radially outward from the inner circumferential wall surface 132d1. The outer peripheral edge of the bottom surface 132d5 is open, and a space 132d7 is formed between the bottom surface 132d5 and the outer circumferential wall surface 132d2. The bottom surface 132d5 is annular and inclined.

[0201] As shown in FIG. 13C , the bottom surface 132d5 of the recess 132d is an inclined surface that tapers outward. This bottom surface 132d5 includes a recessed relief 132h corresponding to the apex of the meshing protrusion 133e (see FIG. 13F ). This relief 132h accommodates the apex of the meshing protrusion 133e when the protrusion 133e enters the recess 132d. The depth and inclination of the relief 132h are set within a range that prevents the relief 132h from reaching the bottom surface of the circular protrusion 132b. It is preferable that the depth be set to a value that allows the apex of the protrusion 133e to enter (accommodate) as much as possible. The bottom surface 132d5 is also formed parallel to the third sidewall surface (upper wall surface) 133e5, which is the friction surface (conical surface) 133a1 of the protrusion 133e. This allows the strength of the bottom side of the recess 132d, and therefore the strength of the drive side fixed pulley 132, to be maintained high by leaving the thickness from the bottom surface 132d5 (relief portion 132h) of the recess 132d to the bottom surface of the circular protrusion 132b, and also allows the thickness of the drive side pulley 131 in the closed state (see Figures 5B and 6A) to be kept small because the top of the protrusion 133e enters the relief portion 132h when the drive side variable pulley 133 and the drive side fixed pulley 132 are closed.

[0202] (Convex portion) As shown in FIG. 13C, the convex portion 132e protrudes toward the left, and the outer peripheral end of the convex portion 132e extends to the inner circumference of the conical outer annular portion 132a3 having a predetermined width, and the inner peripheral end of the convex portion 132e extends to the inner circumference of the large diameter hole portion 132c1 (an extension line of the outer peripheral wall surface of the inner cylindrical portion 132f).

[0203] As shown in FIGS. 13A to 13C, the convex portion 132e has an inner peripheral wall surface 132e1, a first side wall surface 132e3, a second side wall surface 132e4, a third side wall surface (upper wall surface) 132e5, and a fourth side wall surface (lower side surface) 132e6.

[0204] As shown in Fig. 13A, the inner peripheral wall surface 132e1 is an inner peripheral wall surface formed on the convex portion 132e at a predetermined angle α12. As shown in Fig. 13C, the inner peripheral wall surface 132e1 is provided in the axial direction (the axial direction of the drive-side fixed pulley 132) from the conical surface 132a1 to the bottom surface 132d5 of the concave portion 132d. The right half of the inner peripheral wall surface 132e1 (the portion to the right of the left end surface 132f1, which is one end surface of the inner cylindrical portion 132f) is integrally connected to the outer peripheral wall surface of the inner cylindrical portion 132f.

[0205] As shown in Fig. 13A, the first side wall surface 132e3 extends radially from the pulley body 132a. The first side wall surface 132e3 is formed radially from the inner circumferential wall surface 132e1 to the outer circumferential wall surface 132d2. The first side wall surface 132e3 is formed axially from the conical surface 132a1 to the bottom surface 132d5 or the bottom surface 132a2. The first side wall surface 132e3 is identical to the second side wall surface 132d4 of the recess 132d.

[0206] As shown in FIG. 13A , the second side wall surface 132e4 extends radially of the pulley body 132a. The second side wall surface 132e4 is disposed on the side opposite the first side wall surface 132e3 at a predetermined angle α12. The second side wall surface 132e4 extends radially from the inner circumferential wall surface 132e1 to the outer circumferential wall surface 132d2. The second side wall surface 132e4 extends axially from the conical surface 132a1 to the bottom surface 132d5 or the bottom surface 132a2. The second side wall surface 132e4 is identical to the first side wall surface 132d3 of the recess 132d.

[0207] The third side wall surface (upper wall surface) 132e5 connects one end edge (left edge) of the first side wall surface 132e3 to one end edge (left edge) of the second side wall surface 132e4. The fourth side wall surface (lower surface) 132e6 connects the other end edge (right edge) of the first side wall surface 132e3 to the other end edge (right edge) of the second side wall surface 132e4.

[0208] As shown in FIG. 13A , a pair of ridges 132e5a, 132e5a are formed on both sides of the third side wall surface 132e5 along the radial direction (the direction in which the inner diameter of the V-belt 23c expands and contracts). As shown in FIG. 13C , the surfaces of the ridges 132e5a, 132e5a are flush with the conical surface 132a1. Furthermore, a fan-shaped recess (hereinafter sometimes referred to as a fan-shaped recess) 132e5b is formed in the center of the third side wall surface 132e5 between the pair of ridges 132e5a, 132e5a. Thus, the fan-shaped recess 132e5b, which is a friction surface-side recess, and / or the pair of ridges 132e5a, 132e5a, which are friction surface-side protrusions, are formed on the third side wall surface 132e5 side, which is the friction surface between the V-belt 23c and the ridge 132e.

[0209] The sectorial recess 132e5b is provided from the inner periphery of the conical outer annular portion 132a3 to just before the inner circumferential wall surface 132e1. This ensures that the protruding ridges 132e5a, sectorial recesses 132e5b, and protruding ridges 132e5a are alternately arranged along the circumferential direction from the inner periphery of the conical outer annular portion 132a3 to just before the inner circumferential wall surface 132e1.

[0210] The circular protrusion 132b is formed in a disk shape and protrudes coaxially and integrally from the bottom surface 132a2 of the pulley body 132a. The through hole 132c has a large diameter hole portion 132c1, a medium diameter hole portion 132c2 that is smaller in diameter than the large diameter hole portion 132c1, and a small diameter hole portion 132c3 that is smaller in diameter than the medium diameter hole portion 132c2. The large diameter hole portion 132c1, the medium diameter hole portion 132c2, and the small diameter hole portion 132c3 are provided in this order from left to right as shown in FIG. 13C .

[0211] Specifically, the through hole 132c is provided with a cylindrical inner tube portion 132f, and one end surface 132f1 (left end surface 132f1) of the inner tube portion 132f is located in the left-right center of the inner circumferential wall surface 132e1 of the protrusion 132e. The other end surface 132f2 (other end surface 132f2) of the inner tube portion 132f is formed flush with the bottom surface of the circular protrusion 132b. The other end (right end) of the inner tube portion 132f is provided with an annular flange portion 132g extending inward. The inner circumferential wall surface 132e1 of each protrusion 132e defines the large-diameter hole portion 132c1, the inner circumferential wall surface of the inner tube portion 132f defines the medium-diameter hole portion 132c2, and the inner circumferential wall surface of the flange portion 132g defines the small-diameter hole portion 132c3.

[0212] The inner peripheral wall surface of the inner cylindrical portion 132f is provided with a plurality of (four in this embodiment) axially extending ridges 132f3 at predetermined intervals along the circumferential direction. The ridges 132f3 are engaged with the engaging grooves 34a (four engaging grooves 34a in this case) of the center boss 34, and the drive-side fixed pulley 132 is fixed to the center boss 34 while restricting its rotation.

[0213] (Drive side variable pulley) As shown in Figures 13D to 13F, the drive side variable pulley 133 is formed in a roughly conical disk shape, and has a pulley body 133a formed in a conical disk shape, a circular protrusion 133b formed coaxially with the pulley body 133a and protruding from a bottom surface 133a2, and a stepped through hole 133c formed in the center coaxially with the pulley body 133a.

[0214] The pulley body 133a has a conical surface 133a1 and a bottom surface 133a2, which are friction surfaces. The conical surface 133a1 has recesses 133d and protrusions 133e, each of which is formed in a generally fan-shaped configuration when viewed from the right side in FIG. 13F , alternately arranged along the circumferential direction. A plurality of recesses 133d are arranged along the circumferential direction at a predetermined angle α12. The apex angle of each recess 133d is set to a predetermined angle α11. A plurality of protrusions 133e are arranged along the circumferential direction at a predetermined angle α11. The apex angle of each protrusion 133e is set to a predetermined angle α12. The predetermined angles α11 and α12 are set to the same value. Six recesses 133d and six protrusions 133e are formed, and the predetermined angles α11 and α12 are set to 60 degrees. It is preferable to form an even number of recesses 133d and six protrusions 133e.

[0215] (Recess) As shown in Figure 13F, recess 133d opens to the right, and as shown in Figure 13D, the outer peripheral end of recess 133d extends to the inner circumference of conical outer annular portion 133a3 having a predetermined width, and the inner peripheral end of recess 133d extends to the inner circumference of large diameter hole portion 133c1.

[0216] As shown in FIGS. 13D to 13F, the recess 133d has an inner peripheral wall surface 133d1, an outer peripheral wall surface 133d2, a first side wall surface 133d3, a second side wall surface 133d4, a bottom surface 133d5, and an opening 133d6.

[0217] The inner peripheral wall surface 133d1 is an outer peripheral wall surface formed on the inner cylindrical portion 133f at a predetermined angle α11 and spaced a predetermined distance from the inner cylindrical portion 133f. As shown in FIG. 13F, the inner peripheral wall surface 133d1 extends from a right end surface 133f1, which is the other end surface of the inner cylindrical portion 133f, to a bottom surface 133d5.

[0218] As shown in Fig. 13D, the outer peripheral wall surface 133d2 is an inner peripheral wall surface formed at a predetermined angle α11 at a predetermined interval (predetermined angle α12) from the conical outer annular portion 133a3. As shown in Fig. 13F, the outer peripheral wall surface 133d2 is formed in the axial direction from the conical surface 133a1 to the bottom surface 133a2.

[0219] As shown in Fig. 13D, the first side wall surface 133d3 extends radially from the pulley body 133a. The first side wall surface 133d3 is formed radially from the inner peripheral wall surface of the large diameter hole portion 133c1 to the outer peripheral wall surface 133d2. As shown in Fig. 13F, the first side wall surface 133d3 is formed axially from the conical surface 133a1 to the bottom surface 133d5 or the bottom surface 133a2. A notch 133d3a is formed in the first side wall surface 133d3.

[0220] As shown in FIG. 13D , the second side wall surface 133d4 extends radially from the pulley body 133a. The second side wall surface 133d4 faces the first side wall surface 133d3 and is disposed at a predetermined angle α11. The second side wall surface 133d4 extends radially from the inner peripheral wall surface of the large-diameter hole portion 133c1 to the outer peripheral wall surface 133d2. As shown in FIG. 13F , the second side wall surface 133d4 extends axially from the conical surface 133a1 to the bottom surface 133d5 or 133a2. The second side wall surface 133d4 has a notch 133d4a formed therein, similar to the notch 133d3a of the first side wall surface 133d3.

[0221] An opening 133d6 formed in a U-shape and opening radially inward is provided between the inner end of the first side wall surface 133d3, the inner end of the second side wall surface 133d4, and the outer peripheral end of the right end surface 133f1 of the inner cylindrical portion 133f.

[0222] As shown in Fig. 13D, the bottom surface 133d5 is provided by connecting the first side wall surface 133d3 and the second side wall surface 133d4. As shown in Fig. 13F, the bottom surface 133d5 is provided by extending radially outward from the inner circumferential wall surface 133d1. The bottom surface 133d5 is formed into an annular, inclined surface. The outer peripheral edge of the bottom surface 133d5 is open, and a space 133d7 is formed between the bottom surface 133d5 and the outer circumferential wall surface 133d2.

[0223] The bottom surface 133d5 of the recess 133d is an inclined surface that tapers outward, and this bottom surface 133d5 is formed with a relief portion 133h corresponding to the apex of the engaging protrusion 132e so that the apex of the protrusion 132e can escape when the engaging protrusion 132e enters the recess 133d. The depth and inclination of the relief portion 133h are formed within a range that does not separate the large diameter portion 133b1 and the small diameter portion 133b2 of the circular protrusion 133b, and it is preferable that the depth be set to a value that allows the apex of the protrusion 132e to enter as far as possible. In addition, the bottom surface 133d5 is formed so as to be parallel to the third side wall surface (upper wall surface) 132e5, which is the friction surface 132a1 of the protrusion 132e. This maintains a high strength of the bottom side of the recess 133d and therefore of the drive side variable pulley 133 by leaving the connection between the bottom surface 133d5 of the recess 133d and the inner tube portion 133f, and when the drive side variable pulley 133 and the drive side fixed pulley 132 are closed, the top of the convex portion 133e enters the recess portion 133h, so that the thickness of the drive side pulley 131 in the closed state (see Figures 5B and 6A) can be kept small.

[0224] (Convex portion) As shown in FIG. 13F, the convex portion 133e protrudes toward the right, and the outer peripheral end of the convex portion 133e extends to the inner circumference of the conical outer annular portion 133a3 having a predetermined width, and the inner peripheral end of the convex portion 133e extends to the inner circumference of the large diameter hole portion 133c1.

[0225] As shown in Figures 13D to 13F, the convex portion 133e has an inner wall surface 133e1, a first side wall surface 133e3, a second side wall surface 133e4, a third side wall surface (upper wall surface) 133e5, a fourth side wall surface (lower wall surface) 133e6, and a notch portion 133e7.

[0226] As shown in FIG. 13D , the inner circumferential wall surface 133e1 is an inner circumferential wall surface formed on the convex portion 133e at a predetermined angle α12. As shown in FIG. 13F , the inner circumferential wall surface 133e1 extends rightward in the axial direction from a right end surface 133f1, which is the other end surface of the inner cylindrical portion 133f, to the conical surface 133a1. The inner circumferential wall surface 133e1 extends axially from the conical surface 133a1 to a bottom surface 133d5 of the recess 133d. The left half of the inner circumferential wall surface 133e1 (the portion to the left of the right end surface 133f1, which is the other end surface of the inner cylindrical portion 133f) is integrally connected to the outer circumferential wall surface of the inner cylindrical portion 133f.

[0227] As shown in Fig. 13D, the first side wall surface 133e3 extends radially from the pulley body 133a. The first side wall surface 133e3 is formed radially from the inner peripheral wall surface 133e1 to the outer peripheral wall surface 133d2. The first side wall surface 133e3 is formed axially from the conical surface 133a1 to the bottom surface 133d5 or the bottom surface 133a2. The first side wall surface 133e3 is identical to the second side wall surface 133d4 of the recess 133d.

[0228] As shown in FIG. 13D, the second side wall surface 133e4 extends radially from the pulley body 133a. The second side wall surface 133e4 is disposed on the side opposite the first side wall surface 133e3 at a predetermined angle α12. The second side wall surface 133e4 extends radially from the inner circumferential wall surface 133e1 to the outer circumferential wall surface 133d2 (see FIG. 13F). The second side wall surface 133e4 extends axially from the conical surface 133a1 to the bottom surface 133d5 or the bottom surface 133a2. The second side wall surface 133e4 is identical to the first side wall surface 133d3 of the recess 133d.

[0229] The third side wall surface (upper wall surface) 133e5 connects one end edge (right edge) of the first side wall surface 133e3 to one end edge (right edge) of the second side wall surface 133e4. The fourth side wall surface (lower surface) 133e6 connects the other end edge (left edge) of the first side wall surface 133e3 to the other end edge (left edge) of the second side wall surface 133e4.

[0230] As shown in Fig. 13F, the notch 133e7 is formed as a recess that opens toward the left side in the fourth side wall surface (lower surface) 133e6. The first side wall surface 133e3 and the second side wall surface 133e4 also have notches 133e3a and 133e4a corresponding to the notch 133e7. The notch 133e7 is formed radially between the inner periphery of the conical outer annular portion 133a3 and the outer periphery of the circular protrusion 133b.

[0231] As shown in FIG. 13D, a pair of grooves 133e5a, 133e5a are formed radially on both sides of the third side wall surface 133e5. As shown in FIG. 13F, the surfaces of the grooves 133e5a, 133e5a are arranged to be one step lower than the conical surface 133a1. The widths of the pair of grooves 133e5a, 133e5a are preferably set to be the same as the width of the pair of ridges 132e5a, 132e5a. Furthermore, a fan-shaped convex portion (hereinafter sometimes referred to as a fan-shaped convex portion) 133e5b is formed in the center of the third side wall surface 133e5 between the pair of grooves 133e5a, 133e5a. The surface of the fan-shaped convex portion 133e5b is arranged to be flush with the conical surface 133a1. In this way, on the third side wall surface 133e5 side, which is the friction surface of the convex portion 133e with the V-belt 23c, a pair of groove portions 133e5a, 133e5a, which are friction surface side recesses, and / or a fan-shaped convex portion 133e5b, which is a friction surface side convex portion, are formed.

[0232] The fan-shaped convex portions 133e5b are provided from the inner periphery of the conical outer annular portion 133a3 to the inner circumferential wall surface 133e1. This ensures that the groove portions 133e5a, the fan-shaped convex portions 133e5b, and the groove portions 133e5a are alternately arranged along the circumferential direction from the inner periphery of the conical outer annular portion 133a3 to the inner circumferential wall surface 133e1.

[0233] Furthermore, when the V-belt 23c is installed while the drive-side fixed pulley 132 and the drive-side variable pulley 133 are engaged with each other, the grooves 133e5a, the fan-shaped convex portions 133e5b, the grooves 133e5a, the ridges 132e5a, the fan-shaped concave portions 132e5b, and the ridges 132e5a are arranged in a circumferential direction, thereby enabling the provision of repeated concave-convex portions. In this way, providing the concave-convex portions on the friction surfaces 132a1 and 133a1 increases the frictional resistance between the V-belt 23c and the V-belt 23c.

[0234] In particular, the angle of the edges (corners) of these uneven portions is preferably 90 degrees, and the edges are preferably chamfered, such as by C-chamfering, which cuts the corners at an angle, or by R-chamfering, which rounds the corners. When these edges come into contact with the V-belt 23c, it becomes possible to increase the frictional resistance between the V-belt 23c. Therefore, it becomes possible to further increase the frictional force between the V-belt 23c with a simple structure. Note that the edge angle may be set to an obtuse angle greater than 90 degrees. In this way, even the inclined edge surface can come into contact with the V-belt 23c, further increasing the frictional resistance.

[0235] As shown in Figure 13F, the circular protrusion 133b protrudes coaxially and integrally from the bottom surface 133a2 of the pulley body 133a and is formed in a stepped disk shape. The circular protrusion 133b has a large diameter portion 133b1 and a small diameter portion 133b2 that is smaller in diameter than the large diameter portion 133b1. The thrust washer 37, thrust bearing 36, and push plate 43a are mounted in this order on the left end surface of the large diameter portion 133b1.

[0236] The through hole 133c has a large diameter hole portion 133c1 and a small diameter hole portion 133c2 that is smaller in diameter than the large diameter hole portion 133c1. The large diameter hole portion 133c1 and the small diameter hole portion 133c2 are provided in this order from right to left as shown in FIG. 13F.

[0237] Specifically, the through hole 133c is provided with a cylindrical inner tube portion 133f, and the other end surface 33f1 (right end surface 133f1) of the inner tube portion 133f is located in the left-right center of the inner circumferential wall surface 133e1 of the protrusion 133e. One end surface 133f2 (left end surface 33f2) of the inner tube portion 133f is formed flush with the bottom surface of the small diameter portion 133b2 of the circular protrusion 133b. The inner circumferential wall surface 133e1 of each protrusion 133e forms the large diameter hole portion 133c1, and the inner circumferential wall surface of the inner tube portion 133f forms the small diameter hole portion 133c2.

[0238] The inner peripheral wall surface of the inner cylindrical portion 133f is provided with a plurality of (four in this embodiment) axially extending ridges 133f3 at predetermined intervals along the circumferential direction. The ridges 133f3 are engaged with the engaging grooves 35a of the drive-side slide bush 35, and the drive-side slide bush 35 is fixed in the drive-side variable pulley 133 while being restricted from rotating.

[0239] In the bicycle of Patent Document 1 mentioned above, there was a demand to maintain high frictional force between the drive side pulley and driven side pulley and the drive V-belt, but by using the drive side pulley 131 and driven side pulley 51 to which the configuration of the drive side pulley 131 related to the modified example mentioned above is applied, it is possible to maintain high frictional force between the drive side pulley 131 and driven side pulley 51 and the V-belt 23c, and ultimately it is possible to prevent the drive side pulley 131 and driven side pulley 51 from spinning freely.

[0240] (Modifications of Drive Unit of Continuously Variable Transmission Device) Next, modifications of the drive unit 23a of the above-described continuously variable transmission device 23 will be described with reference to FIGS. 14 to 16. In the speed adjustment unit 38 (40) of the above-described drive unit 23a, a shift rake 42 having a cam 41a and linearly moving in the first direction linearly moves the push plate 43a and thus the drive-side variable pulley 33 in the second direction (left-right direction) via a pair of cam followers 43b, 43c that follow the cam 41a. In contrast, in a continuously variable transmission device 223 according to a modification, as shown in FIGS. 14, 15A, and 15B, a rotating member 242 having a spiral groove-shaped cam 241a and rotatingly moves the shift fork 243a and thus the drive-side variable pulley 233 in the second direction (left-right direction) via a follower 243b that follows along the cam 241a.

[0241] 14, the continuously variable transmission 223 includes a driving portion 223a, a driven portion 23b, and a V-belt 23c, similar to the above-described continuously variable transmission 23. Note that, hereinafter, the same components are denoted by the same reference numerals, and description thereof will be omitted.

[0242] (Drive unit) As shown in FIG. 16 , the drive unit 223a (230) mainly includes a drive side pulley 231, a center boss 34, a drive side slide bush 35, a pair of thrust bearings 36, 36, a pair of thrust washers 37, 37, a speed change adjustment unit 238 (240), and a fixing member 239.

[0243] (Drive Side Pulley) The drive side pulley 231 has a drive side fixed pulley 232 and a drive side variable pulley 233. The drive side fixed pulley 232 is fitted and fixed to one end (right end) of the center boss 34. The drive side variable pulley 233 is attached to the center boss 34 via a drive side slide bush 35 that is slidable along the axial direction of the center boss 34 but whose rotation about the axis is restricted.

[0244] (Drive Side Fixed Pulley / Drive Side Variable Pulley) The drive side fixed pulley 232 is configured similarly to the drive side fixed pulley 32 described above, and the drive side variable pulley 233 is configured similarly to the drive side variable pulley 33 described above.

[0245] 14, 15A, and 15B, the speed change adjustment unit 238 (240) adjusts the speed by automatically moving the drive side variable pulley 233 relative to the drive side fixed pulley 232 along the axial direction (left-right direction) of the crankshaft 21a. The speed change adjustment unit 238 includes a cam mechanism 241 and a speed change drive device 244 (speed change drive source).

[0246] (Cam mechanism) As shown in Figure 16, the cam mechanism 241 includes a cam portion 242 that has a cam 241a and rotates, and a follower portion 243 that has a follower 241b that is moved linearly by the cam 241a and can move the drive side variable pulley 233 relatively.

[0247] (Cam portion (rotating member)) As shown in FIG. 16 , the cam portion 242 is mainly composed of a rotating member formed in a cylindrical shape. A spiral groove 242a is formed on the outer peripheral wall surface of the rotating member 242, and a mounting hole 242b to which an output shaft 244a1 of a motor 244a is attached is formed on one end surface of the rotating member 242. The rotating member 242 is preferably disposed so that its axial direction is parallel to the axial direction of the drive-side pulley 231, i.e., the axial direction of the crankshaft 21a (the second direction). The spiral groove 242a functions as a spiral groove-shaped cam 241a that guides and moves the follower 243b.

[0248] (Follower Portion) As shown in FIG. 16 , the follower portion 243 includes a shift fork 243 a, which is a pressing member capable of pressing the drive side variable pulley 233 along the second direction (left-right direction), and a follower 243 b provided on the shift fork 243 a.

[0249] The shift fork 243a has a first annular portion 243a1, a second annular portion 243a2, and a connecting portion 243a3 that connects the first annular portion 243a1 and the second annular portion 243a2. The first annular portion 243a1 is formed in a cylindrical shape, and a through-hole 243a1a is formed in the center of the first annular portion 243a1, into which the rotating member 242 can be inserted and through which it can rotate. A through-hole 243a1b is formed in the outer peripheral wall surface of the first annular portion 243a1, into which the follower 243b can be attached.

[0250] The second annular portion 243a2 is formed in an annular shape, and a through hole 243a2a is formed in the center of the second annular portion 243a2 to rotatably support the drive-side variable pulley 233. Annular recesses 243a2b and 243a2c are formed on both side surfaces of the second annular portion 243a2 to respectively accommodate a pair of thrust bearings 36 (see FIGS. 15A and 15B).

[0251] The connecting portion 243a3 is formed in a plate shape, and one end of the connecting portion 243a3 is integrally connected to the outer peripheral wall surface of the first annular portion 243a1, and the other end of the connecting portion 243a3 is integrally connected to the outer peripheral wall surface of the second annular portion 243a2. The first annular portion 243a1 and the second annular portion 243a2 are arranged so that their axial central positions are on the same plane. Note that the connecting portion 243a3 may be formed (e.g., in a stepped plate shape) so that the axial central positions of the first annular portion 243a1 and the second annular portion 243a2 are offset from each other in the axial direction.

[0252] Although the shift fork 243a is supported by the motor 244a in a cantilevered structure, it may be supported in a double-supported structure. In this case, a guide mechanism may be provided that slidably supports the outer peripheral wall surface of the second annular portion 243a2.

[0253] A cylindrical follower 243b is inserted into and fixed to a through-hole 243a1b in the first annular portion 243a1 of the shift fork 243a. A tip end of the follower 243b is attached to protrude inward from the inner circumferential wall surface of the first annular portion 243a1, and is guided by the spiral groove 242a (spiral groove-shaped cam 241a) of the rotating member 242 to move relatively along the spiral groove 242a. The follower 243b is moved linearly in the second direction (left-right direction) by the spiral groove 242a (spiral groove-shaped cam 241a), and functions as a follower 241b that is capable of moving the drive-side variable pulley 233 relatively.

[0254] (Speed-changing drive device) The speed-changing drive device 244 is a device that drives (rotates) the cam 241a to relatively move the drive-side variable pulley 233. The speed-changing drive device 244 includes a motor 244a that is a speed-changing drive source.

[0255] The motor 244a is a speed-changing drive source that rotates the cam 241a to move the drive-side variable pulley 233 relative to the vehicle. The motor 244a is a rotary electric motor and has a rotating output shaft 244a1. The output shaft 244a1 extends along the second direction (left-right direction). The output shaft 244a1 of the motor 244a is connected to the rotating member 242 so as to rotate integrally with the motor. As shown in FIG. 1 , the motor 244a is fixed to the frame 11 (e.g., to the side surface of the down tube 11d) via a motor bracket (not shown). The axial length of the motor 244a is preferably smaller than the width of the down tube 11d or the width of the hanger portion 11i.

[0256] Furthermore, the motor 244a is preferably disposed in a position along the down tube 11d. In this case, a position along the down tube 11d includes a position along the lower side of the down tube 11d, a position along the upper side of the down tube 11d, and a position along the side of the down tube 11d. Furthermore, the cam mechanism 241, which includes a spiral groove-shaped cam 241a and a follower 241b provided on the shift fork 243a, is also preferably disposed in a position along the down tube 11d. In this way, the cam mechanism 241 and the motor 244a, which is the drive source for gear shifting, are disposed along the down tube 11d, which is a frame that supports the crankshaft 21a, which is the drive shaft.

[0257] 16 , the fixing member 239 is formed in a cylindrical shape and serves to rotatably support and fix the shift fork 243a to the drive side variable pulley 233. The inner diameter of the fixing member 239 is slightly larger than the outer peripheral wall surface of the circular protrusion 33b of the drive side variable pulley 233. For example, the fixing member 239 is a ring nut that is screwed and fixed to the circular protrusion 33b of the drive side variable pulley 233. In this state, the shift fork 243a is rotatably supported between the fixing member 239 and the drive side variable pulley 233.

[0258] (Operation of Continuously Variable Transmission) (Low Gear) In low gear, as shown in FIG. 15A , when the first annular portion 243a1 of the shift fork 243a is in a retreated position relative to the rotating member (cam portion) 242, the shift fork 243a and therefore the driving side variable pulley 233 are in their outermost positions, and the driving side pulley 231 is in an open state. The inner diameter of the V-belt 23c wound around the driving side pulley 231 is at its minimum. On the other hand, the driven side variable pulley 53 is in its innermost position, and the driven side pulley 51 is in a closed state. The inner diameter of the V-belt 23c wound around the driven side pulley 51 is at its maximum.

[0259] When the output shaft 244a1 of the motor 244a is rotated in the second rotation direction RD12 (see FIGS. 15A and 15B ), the first annular portion 243a1 of the shift fork 243a is moved backward to the reverse position (see FIG. 15A ), and the continuously variable transmission 223 can be shifted to the low gear shown in FIG. 15A . The V-belt 23c wound around the drive-side pulley 231 is constantly pulled by the driven-side pulley 51 by the tension maintaining unit 57 (coil spring 57a). Therefore, the tension of the V-belt 23c is maintained constant even when the first annular portion 243a1 of the shift fork 243a is moved backward, and the drive-side variable pulley 233 is moved to the outermost position, and the inner diameter of the V-belt 23c wound around the drive-side pulley 231 becomes the minimum diameter. The second rotation direction RD12 is opposite to the first rotation direction RD11, and is counterclockwise when the rotation member 242 is viewed from the right in FIGS. 15A and 15B.

[0260] (High Gear) In high gear, as shown in Figures 14 and 15B, when the first annular portion 243a1 of the shift fork 243a is in a forward position relative to the rotating member (cam portion) 242, the shift fork 243a and therefore the drive-side variable pulley 233 are in their innermost positions, and the drive-side pulley 231 is in a closed state. The inner diameter of the V-belt 23c wound around the drive-side pulley 231 is at its maximum. Meanwhile, the driven-side variable pulley 53 is in its outermost position, and the driven-side pulley 51 is in an open state. The inner diameter of the V-belt 23c wound around the driven-side pulley 51 is at its minimum.

[0261] When the output shaft 244a1 of the motor 244a is rotated in the first rotation direction RD11, the first annular portion 243a1 of the shift fork 243a moves forward to the forward position (see FIG. 15B ), and the continuously variable transmission 223 can shift to the high gear shown in FIG. 15B . The V-belt 23c wound around the drive pulley 231 is constantly pulled by the driven pulley 51 by the tension maintaining unit 57 (coil spring 57a). Therefore, the tension of the V-belt 23c is maintained constant even while the first annular portion 243a1 of the shift fork 243a is moving forward. The drive variable pulley 233 is moved to the innermost position, and the inner diameter of the V-belt 23c wound around the drive pulley 231 becomes the maximum diameter. The first rotation direction RD11 is clockwise when the rotating member 242 is viewed from the right in FIGS. 15A and 15B .

[0262] The modified continuously variable transmission 223 can automatically move the drive-side variable pulley 233 with a relatively simple structure. Also, the cam mechanism 241 and the transmission drive source 244a, i.e., the transmission adjustment unit 238, can be made compact and placed in an optimal location that does not interfere with the driver's operation.

[0263] (Modification (Shift Rake)) Next, a modification of the above-described shift rake 42 will be described with reference to Fig. 17. Although the inclined surface 42d1 of the above-described shift rake 42 is formed as a flat surface, the inclined surface 342d1 according to the modification may be formed as a predetermined concave or convex curved surface, as shown in Fig. 17.

[0264] The cam portion 342 is configured as a bifurcated fork-shaped shift rake, similar to the above-described cam portion 42. The shift rake 342, similar to the above-described shift rake 42, has a T-shaped base portion 342a and a pair of cam main portions 342b, 342c (cam main portion 342c is not shown) integrally provided at both front and rear ends of the base portion 342a.

[0265] The cam main body 342b is formed in a rod shape, similar to the cam main body 42b described above. The base end of the cam main body 342b is connected to the rear end of the base 342a, and the cam main body 342b is provided so as to extend obliquely downward and rearward in the first direction (see FIG. 1). As shown in FIG. 17, a tapered portion 342d is formed at the tip of the cam main body 342b. The tapered portion 342d has an inclined surface 342d1 formed so as to be tapered.

[0266] As shown in FIG. 17 , the inclined surface 342d1 has a recess 342d1a and a protrusion 342d1b. The recess 342d1a is a portion recessed relative to the inclined surface 42d1, and the protrusion 342d1b is a portion protruding relative to the inclined surface 42d1. The recess 342d1a has a gentle slope portion S11 whose angle with respect to the imaginary plane P1 is smaller than the predetermined angle θ of the inclined surface 42d1, and a steep slope portion S21 whose angle with respect to the imaginary plane P1 is larger than the predetermined angle θ. The protrusion 342d1b has a steep slope portion S22 whose angle with respect to the imaginary plane P1 is larger than the predetermined angle θ, and a gentle slope portion S12 whose angle with respect to the imaginary plane P1 is smaller than the predetermined angle θ of the inclined surface 42d1.

[0267] At the lowest part (most recessed part) of the recess 342d1a, the angle it forms with the imaginary plane P1 is the same as the predetermined angle θ of the inclined surface 42d1, and this point is the boundary between the gentle slope portion S11 and the steep slope portion S21. At the highest part (most protruding part) of the protrusion 342d1b, the angle it forms with the imaginary plane P1 is the same as the predetermined angle θ of the inclined surface 42d1, and this point is the boundary between the gentle slope portion S12 and the steep slope portion S22. The gentle slope portion S1 is made up of the gentle slope portion S11 and the gentle slope portion S12, and the steep slope portion S2 is made up of the steep slope portion S21 and the steep slope portion S22.

[0268] The inclined surface 342d1 includes a same-angle inclined surface S31, whose angle with respect to the imaginary plane P1 is the same as the predetermined angle θ of the inclined surface 42d1, a gentle inclined surface S11, a steep inclined surface S21, a steep inclined surface S22, a gentle inclined surface S12, and a same-angle inclined surface S32, whose angle with respect to the imaginary plane P1 is the same as the predetermined angle θ of the inclined surface 42d1, which are connected in this order from the tip. Each of the inclined surface portions S11, S12, S21, and S22 is formed as a curved surface with a constant radius of curvature or a curved surface formed by combining multiple curved surfaces with different radii of curvature, and the inclined surface portions S11, S12, S21, and S22 are smoothly connected.

[0269] The inclined surfaces S11, S12, S21, and S22 are not limited to curved surfaces and may be flat surfaces. In this case, the inclined surfaces S11, S12, S21, and S22 may be formed so that a plurality of flat surfaces with different inclination angles are provided continuously.

[0270] The inclined surface 342d1 functions as a cam 41a that guides and follows the cam follower 43b. The inclined surface 42d1 described above is flat, and the angle it forms with respect to the virtual plane P1 is set constant at a predetermined angle θ. Therefore, when the output rotation speed of the motor 44a is constant, the cam follower 43b moves left and right at a constant speed, and the push plate 43a also moves left and right at a constant speed. Therefore, the opening and closing speed of the drive pulley 31 is constant, and the speed change speed (the amount of speed change per unit time) is also set constant. In contrast, the inclined surface 342d1 has unevenness. Therefore, when the output rotation speed of the motor 44a is constant, the cam follower 43b moves left and right at a speed corresponding to the unevenness, and the push plate 43a also moves left and right at a speed corresponding to the unevenness. Therefore, the opening and closing speed of the drive pulley 31 corresponds to the unevenness, and the speed change speed can also be set to a speed corresponding to the unevenness.

[0271] In the steep slope section S2 (S21, S22), when the output rotation speed of the motor 44a is constant, the movement amount of the cam follower 43b increases, and the movement amount of the push plate 43a also increases, allowing for a faster shift speed. On the other hand, in the gentle slope section S1 (S11, S12), when the output rotation speed of the motor 44a is constant, the movement amount of the cam follower 43b decreases, and the movement amount of the push plate 43a also decreases, allowing for a slower shift speed. In this modified example, the shift speed in the middle range (the area corresponding to the steep slope section S21 and the steep slope section S22) is set to be faster than the shift speed in the upper range (the area corresponding to the gentle slope section S12) and the lower range (the area corresponding to the gentle slope section S11). Thus, this modified example allows for a simple structure to appropriately change the shift speed to a desired value for each shift range.

[0272] Note that the spiral groove 242a of the rotating member 242 of the continuously variable transmission 223 according to the above-described modified example may be formed so that the inclination angle varies, similar to the inclined surface 342d1 having a varying inclination angle described above. Since the spiral groove according to this modified example has a varying inclination angle, when the output rotation speed of the motor 244a is constant, the follower 243b of the shift fork 243a moves left and right at a speed that corresponds to the inclination of the spiral groove. Therefore, the opening and closing speed of the drive pulley 231 corresponds to the inclination of the spiral groove, and the shift speed can also be set to a speed that corresponds to the inclination of the spiral groove.

[0273] (Modifications (Frame)) Next, modifications of the frame 11 described above will be described with reference to FIGS. 18 to 31. In the frame 11 described above, the bottom bracket 22 that supports the crank 21 is housed in the hanger portion 11i, and the shift rake 42 is movably disposed outside the hanger portion 11i and to the side of the down tube 11d. In contrast, a frame 411 according to a modification is provided with a crankcase 60 that can movably house the shift rake 42 therein instead of the hanger portion 11i, and has a down tube 411d that houses the motor 44a that is the drive source for the shift rake 42 inside. Note that the same members as those in the above-described embodiment and modification are designated by the same reference numerals, and their description will be omitted.

[0274] (Frame) As shown in FIG. 18, the frame 411 is a frame-shaped structure that forms the framework of the bicycle, similar to the frame 11 described above, and has a head tube 11a, a seat tube 411b, a top tube 11c, a down tube 411d, an upper stay 11e, and a lower stay 411f.

[0275] The seat tube 411b is basically configured in the same manner as the above-described seat tube 11b. As shown in FIG. 18 , the crankcase 60 is connected to the lower end of the seat tube 411b, into which the bottom bracket 22, which rotatably supports the crankshaft 21a, is inserted and fixed. The lower end of the seat tube 411b is formed with an attachment portion 411b1 that can be detachably attached to a first attachment protrusion 61a of the crankcase 60. The attachment portion 411b1 is formed with a groove-shaped attachment recess 411b2 that fits into the first attachment protrusion 61a, and is fixed to the first attachment protrusion 61a with screws while fitted into it.

[0276] As shown in Figures 18 and 21, the down tube 411d has a bifurcated lower half (or rear half) and includes an upper down tube 411d1 and a pair of lower down tubes 411d2, 411d3. The upper down tube 411d1 is cylindrical (e.g., pipe-shaped), and the front end of the upper down tube 411d1 is connected to the lower end of the head tube 11a. The front ends of the pair of lower down tubes 411d2, 411d3 are connected to the rear end of the upper down tube 411d1. The battery 18 is removably housed within the upper down tube 411d1.

[0277] The pair of lower down tubes 411d2, 411d3 are formed in a cylindrical (e.g., pipe) shape, and the front ends of the pair of lower down tubes 411d2, 411d3 are connected and fixed to both left and right sides of the rear end of the upper down tube 411d1 by welding or the like. The pair of lower down tubes 411d2, 411d3 extend in the same direction as the upper down tube 411d1 (first direction (see FIG. 1)) and are arranged opposite and parallel to each other. The pair of lower down tubes 411d2, 411d3 are arranged side by side at a predetermined distance in the left-right direction. Note that the pair of lower down tubes 411d2, 411d3 may also be arranged side by side in the up-down direction.

[0278] 18, the crankcase 60 is connected to the rear end of the down tube 411d, i.e., the rear ends of the pair of lower down tubes 411d2, 411d3. A pair of mounting portions 411d2a, 411d3a are formed at the rear ends of the pair of lower down tubes 411d2, 411d3, which can be detachably attached to the pair of second mounting protrusions 61b1, 61b2 of the crankcase 60. The mounting portion 411d2a has a mounting recess 411d2a1 cut out to have a semi-elliptical cross section that engages with the second mounting protrusion 61b1, and is fixed to the second mounting protrusion 61b1 with screws while engaged with it. The mounting portion 411d3a has a mounting recess 411d3a1 cut out in a semi-elliptical cross section to engage with the second mounting protrusion 61b2, and is fixed to the second mounting protrusion 61b2 by screws while engaged with the second mounting protrusion 61b2.

[0279] As shown in FIGS. 18 and 21, the down tube 411d has a connecting bracket 411d4 and a motor bracket 411d5.

[0280] The connecting bracket 411d4 is a member for connecting the rear ends of the pair of lower down tubes 411d2, 411d3. The connecting bracket 411d4 is disposed between the pair of lower down tubes 411d2, 411d3. The left end of the connecting bracket 411d4 is connected to the side surface (inner surface) of the lower down tube 411d2, for example, by welding, and the right end of the connecting bracket 411d4 is connected to the side surface (inner surface) of the lower down tube 411d3, for example, by welding. In addition, a bearing 411d4a (e.g., a bearing) for rotatably supporting the shift shaft 44b is provided in the center of the connecting bracket 411d4 in the left-right direction.

[0281] The motor bracket 411d5 is a member for positioning the motor 44a between the pair of lower down tubes 411d2, 411d3. The motor bracket 411d5 is disposed in front of the connecting bracket 411d4. The motor bracket 411d5 is integrally formed in a box shape with at least an opening at the top, and as shown in FIG. 21 , has a bottom wall 411d5a, a left side wall 411d5b, a right side wall 411d5c, and a rear side wall 411d5d. Although the front side wall is omitted in this modification, a front side wall may be provided.

[0282] The left side wall 411d5b of the motor bracket 411d5 is fixed to the lower down tube 411d2 by screws or the like, and the right side wall 411d5c is fixed to the lower down tube 411d3 by screws or the like. A motor 44a is disposed within the motor bracket 411d5 with its output shaft 44a1 facing rearward in the first direction (specifically, toward the connecting bracket 411d4 and ultimately the bottom bracket 22), and the output shaft 44a1 protrudes from an opening (not shown) in the rear side wall 411d5d. The motor 44a is fixed to the rear side wall 411d5d or the bottom wall 411d5a by screws or the like.

[0283] In this manner, the motor 44a, shift shaft 44b, and shift rake 42 can be housed between the pair of lower down tubes 411d2, 411d3. Also, the motor 44a, shift shaft 44b, and shift rake 42 can be provided along the down tube 411d.

[0284] As shown in FIG. 18 , one end (upper end) of each of the left and right upper stays 11e1 and 11e2 is connected to the upper end of the seat tube 411b. The lower stay 411f also has a pair of opposing left and right lower stays 411f1 and 411f2. Each of the left and right lower stays 411f1 and 411f2 is formed in a cylindrical (e.g., pipe) shape, and one end (front end) of each of the left and right lower stays 411f1 and 411f2 is connected to the lower end (e.g., mounting portion 411b1) of the seat tube 411b. The other end (rear end) of each of the left and right lower stays 411f1 and 411f2 is connected to the other end (lower end) of each of the left and right upper stays 11e1 and 11e2, similar to the left and right lower stays 11f1 and 11f2.

[0285] (Crankcase) The crankcase 60 is connected to the seat tube 11b and the down tube 11d, similar to the hanger portion 11i described above. The crankcase 60 has the bottom bracket 22, which rotatably supports the crankshaft 21a, inserted and fixed therein, and can movably accommodate the shift rake 42 therein.

[0286] As shown in FIGS. 22 to 27, the crankcase 60 includes an outer cylinder 61, an inner cylinder 62, a first partition wall 63, and a second partition wall 64.

[0287] The outer cylinder 61 is cylindrically formed, and the seat tube 411b and down tube 411d (see FIG. 18) are detachably attached to it. A first mounting protrusion 61a and a pair of second mounting protrusions 61b1, 61b2 protrude from the outer peripheral wall surface of the outer cylinder 61. A groove-shaped mounting recess 411b2 formed in a mounting portion 411b1 at the lower end of the seat tube 411b is screwed and fixed to the first mounting protrusion 61a. Mounting recesses 411d2a1, 411d3a1 formed in a pair of mounting portions 411d2a, 411d3a at the rear ends of a pair of lower down tubes 411d2, 411d3 are screwed and fixed to the pair of second mounting protrusions 61b1, 61b2.

[0288] As shown in Fig. 22, an opening 61c is formed on the outer peripheral wall surface of the outer cylinder 61 between the pair of second mounting protrusions 61b1, 61b2. The opening 61c is an opening through which the shift rake 42 advances and retreats, and is formed in a rectangular shape large enough to allow the shift rake 42 to advance and retreat. The opening 61c is disposed between the first partition wall 63 and the second partition wall 64. The annular space formed between the first partition wall 63 and the second partition wall 64 may be referred to as a shift rake accommodation chamber capable of accommodating the shift rake 42.

[0289] As shown in Figure 27, the outer cylinder 61 accommodates the shift rake 42 so that it can move forward and backward. The outer cylinder 61 is sized to completely accommodate the shift rake 42 in the forward position in high gear. On the other hand, the shift rake 42 (shown by dashed lines in Figure 27) in the reverse position in low gear is accommodated in the outer cylinder 61 with its tip end contacting the cam followers 443b, 443c and with the base 42a and the base ends of the pair of cam main bodies 42b, 42c protruding outside the outer cylinder 61.

[0290] As shown in FIGS. 23 to 26 , the inner cylinder 62 is cylindrical and coaxially disposed within the outer cylinder 61. The axial length of the inner cylinder 62 is set shorter than that of the outer cylinder 61. The inner cylinder 62 is connected and fixed to the first partition 63 and the second partition 64 while passing through them. The inner cylinder 62 is supported at both ends by the first partition 63 and the second partition 64. The bottom bracket 22 is inserted and fixed within the inner cylinder 62. Furthermore, as shown in FIG. 27 , the inner cylinder 62 is preferably disposed between the pair of cam bodies 42b, 42c of the shift rake 42 and in a position where it does not interfere with the base 42a of the shift rake 42 when in the forward position in the high gear state.

[0291] As shown in Fig. 23 , the first partition 63 is formed in the shape of an annular plate, with the outer peripheral edge of the first partition 63 connected to the inner peripheral wall surface of the outer cylinder 61 and the inner peripheral edge of the first partition 63 connected to the outer peripheral wall surface of the inner cylinder 62. As shown in Fig. 26 , the first partition 63 is provided on the side closer to the push plate 443a and disposed opposite the push plate 443a. As shown in Fig. 23 , the first partition 63 is formed with a pair of openings 63a, 63b through which the pair of support portions 443a2, 443a3 (see Fig. 26 ) of the push plate 443a are respectively inserted.

[0292] 23 and 26, the opening 63a has a first opening 63a1 through which the support portion 443a2 can be inserted, a second opening 63a2 through which the cam follower 443b can be inserted, and a third opening 63a3 in which the guided portion 443d is disposed. A pair of guide rails 63a3a, 63a3b that guide the guided portion 443d are connected and fixed to the third opening 63a3.

[0293] As shown in FIG. 25 (only the guide rail 63a3a is shown), the pair of guide rails 63a3a, 63a3b extend in the left-right direction and penetrate the first partition wall 63 to the second partition wall 64. The pair of guide rails 63a3a, 63a3b are connected and fixed to the first partition wall 63 and the second partition wall 64. The pair of guide rails 63a3a, 63a3b are supported at both ends by the first partition wall 63 and the second partition wall 64, thereby reinforcing the first partition wall 63 and the second partition wall 64 in the axial direction and improving their rigidity. In addition, the pair of guide rails 63a3a, 63a3b are each formed with ridge portions 63a3a1, 63a3b1 over the entire length in the longitudinal direction (left-right direction) that slidably engage with and guide the guided portion 443d.

[0294] 23 and 26, similar to the opening 63a, the opening 63b has a first opening 63b1 through which the support portion 443a3 can be inserted, a second opening 63b2 through which the cam follower 443c can be inserted, and a third opening 63b3 in which the guided portion 443e is disposed. A pair of guide rails 63b3a, 63b3b that guide the guided portion 443e are connected and fixed to the third opening 63b3.

[0295] As shown in FIG. 25 (only the guide rail 63b3a is shown), the pair of guide rails 63b3a, 63b3b extend in the left-right direction and are disposed so as to penetrate the first partition wall 63 and extend to the second partition wall 64. The pair of guide rails 63b3a, 63b3b are connected and fixed to the first partition wall 63 and the second partition wall 64. The pair of guide rails 63b3a, 63b3b are supported at both ends by the first partition wall 63 and the second partition wall 64, thereby reinforcing the first partition wall 63 and the second partition wall 64 in the axial direction and improving their rigidity. In addition, the pair of guide rails 63b3a, 63b3b are each formed with ridge portions 63b3a1, 63b3b1 over the entire length in the longitudinal direction (left-right direction) that slidably engage with and guide the guided portion 443e.

[0296] 24, the second partition 64 is formed in the shape of an annular plate, with the outer peripheral edge of the second partition 64 connected to the inner peripheral wall surface of the outer cylinder 61 and the inner peripheral edge of the second partition 64 connected to the outer peripheral wall surface of the inner cylinder 62. As shown in FIG. 26, the second partition 64 is provided on the side farther from the push plate 443a and is disposed opposite and parallel to the first partition 63.

[0297] Rollers 65a, 65b for slidably supporting the cam bodies 42b, 42c of the shift rake 42 are rotatably attached to the mounting openings 64a1, 64a2 of the second partition 64. The rollers 65a, 65b are rotatably attached to the periphery of the mounting openings 64a1, 64a2, respectively. Note that instead of the rollers, a highly lubricating member may be used as a spacer. This allows the openings in the second partition 64 to be omitted, thereby improving waterproofing.

[0298] A pair of support posts 64b, 64b for attaching the crankcase cover 71 are integrally formed with the second partition wall 64. The pair of support posts 64b, 64b are formed to protrude outward from the outer wall surface of the second partition wall 64. The second partition wall 64 also has mounting screw holes 64c1, 64c2 for attaching the support posts for attaching the control boards 17a, 17b. The mounting screw hole 64c1 is a screw hole for attaching the control board 17a, and the mounting screw hole 64c2 is a screw hole for attaching the control board 17b. The space formed between the second partition wall 64 and the crankcase cover 71 may also be referred to as a control device housing chamber for accommodating the control boards 17a and 17b that constitute the control device 17.

[0299] (Push Plate) As shown in FIG. 26 , the push plate 443a is formed in the shape of an annular plate, similar to the push plate 43a, and a pair of support portions 443a2, 443a3 is provided on the outer peripheral edge of the push plate 443a. The pair of support portions 443a2, 443a3 is set to be longer in the axial direction than the pair of support portions 43a2, 43a3 described above. A pair of cam followers 443b, 443c configured similarly to the pair of cam followers 43b, 43c described above is provided coaxially and rotatably on the inner side of the tip ends of the pair of support portions 443a2, 443a3. The pair of cam followers 443b, 443c are arranged at the same height and spaced a second predetermined distance from the push plate 443a, which is longer than the first predetermined distance described above.

[0300] A pair of rollers 443d, 443e configured similarly to the pair of rollers 43d, 43e described above are coaxially and rotatably provided on the outer sides of the distal ends of the pair of support portions 443a2, 443a3. The roller 443d has flanges formed on both ends, and the side surface of the roller 443d functions as the guided portion 443d that is slidably guided by the pair of guide rails 63a3a, 63a3b. The roller 443e has flanges formed on both ends, and the side surface of the roller 443e functions as the guided portion 443e that is slidably guided by the pair of guide rails 63b3a, 63b3b. The roller 443d is attached by a nut 443g that is threaded onto the threaded portion of the cam follower 443b, with a collar 443f attached between the roller 443d and the cam follower 443b. The roller 443e is attached by a nut 43g that is screwed onto the threaded portion of the cam follower 443c, with a collar 443f attached between the roller 443e and the cam follower 443c.

[0301] (Cover) (Crankcase Cover) As shown mainly in Figure 20, the crankcase cover 71 is a disk-shaped cover for liquid-tightly closing the left opening of the crankcase 60. As shown in Figures 28 and 29, the crankcase cover 71 has a central opening 71a provided in the center, attachment openings 71b provided on the periphery, and an annular wall portion 71c provided on the periphery.

[0302] As shown in Figure 20, the left end of the crankshaft 21a is inserted into the central opening 71a. As shown in Figure 29, an annular groove 71a1 into which an annular seal member 71d is fitted is provided around the inner edge of the central opening 71a. The left end of the bottom bracket 22 is disposed in contact with the inner edge of the central opening 71a, and the annular seal member 71d can liquid-tightly seal the gap between the inner end of the central opening 71a and the left end of the bottom bracket 22.

[0303] 29, the mounting opening 71b is an opening through which a screw (not shown) that threads into a support 64b formed in the second partition wall 64 (see FIG. 25) passes to fix the crankcase cover 71 to the crankcase 60. A through-hole through which the screw is inserted is formed in the center of the mounting opening 71b, and the inner end of the mounting opening 71b is shaped to engage with the support 64b.

[0304] The annular wall portion 71c is disposed in a state of being fitted inside the outer cylinder 61 of the crankcase 60. An annular groove 71c1 into which an annular seal member 71e is fitted is provided on the outer peripheral wall surface of the annular wall portion 71c. The gap between the outer peripheral wall surface of the annular wall portion 71c and the inner peripheral wall surface of the outer cylinder 61 of the crankcase 60 can be liquid-tightly sealed by the annular seal member 71e.

[0305] (Down tube cover) The down tube cover 72 is a member for covering the down tube 411d, as shown mainly in Figures 19 and 20. The down tube cover 72 preferably covers the down tube 411d in a liquid-tight manner. As shown in Figure 30, the down tube cover 72 is divided into upper and lower parts along the longitudinal direction, and has an upper down tube cover 72a that covers the upper side of the down tube 411d and a lower down tube cover 72b that covers the lower side of the down tube 411d.

[0306] The upper down tube cover 72a has an upper tube cover portion 72a1 that covers the upper half of the down tube 411d, and an upper case cover portion 72a2 that covers the front upper half of the crankcase 60. The upper down tube cover 72a covers the pair of lower down tubes 411d2, 411d3 over the entire longitudinal length, and is configured to cover about half of the upper down tube 411d1 rather than the entire longitudinal length, thereby covering a predetermined range (for example, an insertion inlet cover for the battery 18).

[0307] The upper tube cover portion 72a1 is essentially U-shaped in cross section. The front portion 72a1a of the upper tube cover portion 72a1 is formed to cover the upper down tube 411d1 with a small gap. The side portions 72a1b of the upper tube cover portion 72a1 are formed to protrude in the left-right direction to cover the pair of lower down tubes 411d2, 411d3. The rear portion 72a1c of the upper tube cover portion 72a1 is formed to protrude upward relative to the front portion 72a1a so as to ensure a necessary and sufficient retraction space for the shift rake 42 to retract to the reverse position (see FIGS. 5A and 27). The front portion 72a1a and the rear portion 72a1c of the upper tube cover portion 72a1 are connected by an intermediate portion 72a1d having an inclined surface.

[0308] The upper case cover portion 72a2 is essentially formed in the shape of approximately one-quarter of a cylindrical member. The rear end of the upper tube cover portion 72a1 is connected to the outer peripheral wall surface of the upper case cover portion 72a2. As shown primarily in FIG. 31 , a rectangular opening 72a2a is formed in the inner peripheral wall surface of the upper case cover portion 72a2, constituting the upper half of the shift rake opening for inserting the shift rake 42. A U-shaped flange portion 72a2b protrudes rearward from the periphery of the opening 72a2a. The flange portion 72a2b fits into the upper half of the opening 61c of the crankcase 60. A U-shaped groove 72a2c is formed on the outer periphery of the base end of the flange portion 72a2b, into which the upper half of a rectangular, annular seal member (not shown) fits. The seal member seals between the down tube cover 72 and the crankcase 60.

[0309] As shown primarily in Figure 31, the inner peripheral wall surface of upper case cover portion 72a2 is formed with a semicircular opening 72a2d that forms the upper half of the left lower down tube opening, through which lower down tube 411d2 (see Figure 18) is inserted. The inner peripheral wall surface of upper case cover portion 72a2 is formed with a semicircular opening 72a2e that forms the upper half of the right lower down tube opening, through which lower down tube 411d3 (see Figure 18) is inserted.

[0310] As shown in Figures 30 and 31, the lower down tube cover 72b has a lower tube cover portion 72b1 that covers the lower half of the down tube 411d, and a lower case cover portion 72b2 that covers the front lower half of the crankcase 60.

[0311] The lower tube cover portion 72b1 is essentially U-shaped in cross section. The front portion 72b1a of the lower tube cover portion 72b1 is formed to cover the upper down tube 411d1 with a small gap. The side portions 72b1b of the lower tube cover portion 72b1 are formed to protrude in the left-right direction to cover the pair of lower down tubes 411d2, 411d3. The rear portion 72b1c of the lower tube cover portion 72b1 is formed to protrude downward relative to the front portion 72b1a so as to ensure a necessary and sufficient retraction space for the shift rake 42 to retract to the reverse position (see FIGS. 5A and 27). The front portion 72b1a and the rear portion 72b1c of the lower tube cover portion 72b1 are connected by an intermediate portion 72b1d having an inclined surface.

[0312] The lower case cover portion 72b2 is essentially formed in a shape that is approximately one-quarter the circumference of a cylindrical member. The rear end of the lower tube cover portion 72b1 is connected to the outer peripheral wall surface of the lower case cover portion 72b2. As shown primarily in FIG. 31 , a rectangular opening 72b2a is formed in the inner peripheral wall surface of the lower case cover portion 72b2, constituting the lower half of the shift rake opening through which the shift rake 42 is inserted. A U-shaped flange portion 72b2b protrudes rearward from the periphery of the opening 72b2a. The flange portion 72b2b fits into the lower half of the opening 61c of the crankcase 60. A U-shaped groove 72b2c is formed on the outer periphery of the base end of the flange portion 72b2b, into which the lower half of a rectangular, annular seal member (not shown) fits.

[0313] As shown primarily in Figure 31, the inner peripheral wall surface of lower case cover portion 72b2 is formed with a semicircular opening 72b2d that forms the lower half of the left lower down tube opening, through which lower down tube 411d2 (see Figure 18) is inserted. The inner peripheral wall surface of lower case cover portion 72b2 is formed with a semicircular opening 72b2e that forms the lower half of the right lower down tube opening, through which lower down tube 411d3 (see Figure 18) is inserted.

[0314] The above-mentioned upper down tube cover 72a is fastened to the lower down tube cover 72b or the down tube 411d with screws (not shown) or engaged with an engaging member such as a grommet. Also, the above-mentioned lower down tube cover 72b is fastened to the upper down tube cover 72a or the down tube 411d with screws (not shown) or engaged with an engaging member such as a grommet.

[0315] According to this modification, the shift rake 42 can be housed within the crankcase 60, and the motor 44a, which is the drive source (shift drive source) of the shift rake 42, can be housed between the pair of lower down tubes 411d2, 411d3, i.e., within the down tube 411d. In other words, the cam mechanism and the shift drive source can be arranged along the down tube 411d, which is a frame connected to the crankshaft 21a (drive shaft). This allows the cam mechanism and the shift drive source, i.e., the shift adjustment unit, to be located in an optimal location that does not interfere with the rider's operation.

[0316] In addition, in the modified example of the frame described above, a drivetrain 415 (see Figure 18) equipped with a crankcase 60, a crank 21, a bottom bracket (bearing) 22 (see Figure 2), and a continuously variable transmission 423 (see Figure 18) is used instead of the drivetrain 15 described above.

[0317] Furthermore, in the above-described frame modification, a down tube cover 572 with an increased longitudinal length may be used instead of the down tube cover 72. In this case, as shown in FIG. 32 , the down tube cover 572 is configured to cover the entire longitudinal length of the upper down tube 411d1 (see FIG. 18 ). Like the above-described down tube cover 72, the down tube cover 572 is divided into upper and lower halves, and includes an upper down tube cover 572a and a lower down tube cover 572b. This long down tube cover 572 can reliably cover the entire longitudinal length of the upper down tube 411d1, reliably providing a liquid-tight seal, and improving the aesthetics and design.

[0318] (Modification (Drive Unit 630)) A modification of the drive unit 30 described above will be further described with reference to Figures 33 and 34. The drive unit 630 according to the modification mainly includes a drive-side pulley 631, a center boss 634, a drive-side slide bush 635, a thrust bearing 36, a thrust washer 37, a speed change adjustment unit 38 (40), a slider housing 81, a drive assist unit 616, and a crankcase unit 660, as shown in Figure 34 .

[0319] (Drive Side Pulley) The drive side pulley 631 has a drive side fixed pulley 632 that is the fixed pulley of the drive side pulley 631, and a drive side variable pulley 633 that is the variable pulley of the drive side pulley 631. The drive side fixed pulley 632 is fitted and fixed to one end (right end) of a center boss 634 that connects and fixes the crankshaft 21a and the right crank 21c (see FIG. 2), and the drive side fixed pulley 632 is fixed and restricted from rotation by the center boss 634. The drive side variable pulley 633 is attached to the center boss 634 via a drive side slide bush 635 that is slidable along the axial direction of the center boss 634.

[0320] (Drive Side Fixed Pulley / Drive Side Variable Pulley) The drive side fixed pulley 632 has basically the same configuration as the drive side fixed pulley 32 described above. The drive side variable pulley 633 has basically the same configuration as the drive side variable pulley 33 described above (see FIG. 7, etc.). The drive side variable pulley 633 is attached to a rotating part of the bottom bracket 22 (see FIGS. 6A and 6B) via a slider housing 81 so as to be rotatable integrally with it. The drive side variable pulley 633 has a pulley body 33a (see FIG. 8F), a circular protrusion 633b, and a stepped through hole 633c.

[0321] The circular protrusion 633b is formed in a stepped disk shape and protrudes coaxially and integrally from the bottom surface 33a2 of the pulley body 33a. The circular protrusion 633b has a large diameter portion 33b1 (see FIG. 8F) and a small diameter portion 633b2 that is smaller in diameter than the large diameter portion 33b1.

[0322] The through-hole 633c is formed through the center of the pulley body 33a and the circular protrusion 633b and includes a large-diameter hole portion 33c1 (see FIG. 8F) and a small-diameter hole portion 633c2 that is smaller in diameter than the large-diameter hole portion 33c1. The small-diameter hole portion 633c2 is configured as a stepped hole portion and includes a first small-diameter hole portion 633c2a and a second small-diameter hole portion 633c2b that is larger in diameter than the first small-diameter hole portion 633c2a. A drive-side slide bush 635 is press-fitted and fixed into the first small-diameter hole portion 633c2a, and a slider housing 81 is housed in the second small-diameter hole portion 633c2b so as to be slidable in the axial direction relative to the first small-diameter hole portion 633c2b. The inner peripheral wall surface 33e1 (see FIG. 8F) of each protrusion 33e defines the large-diameter hole portion 33c1, and the inner peripheral wall surface of the inner cylindrical portion 633f defines the small-diameter hole portion 633c2.

[0323] The inner peripheral wall surface of the second small-diameter hole portion 633c2b is provided with a plurality of (three in this embodiment) axially extending ridge portions 633f3 at predetermined intervals along the circumferential direction. The ridge portions 633f3 are slidably engaged with the sliding engagement portion 81b1 of the slider housing 81 via the slider 82, and the slider housing 81 is housed within the drive-side variable pulley 633 in a rotation-restricted manner (integrally rotatable) and axially slidable manner.

[0324] (Center Boss / Slide Bush (Sliding Metal)) As shown in Figure 34, the center boss 634 is formed in a cylindrical shape and serves to fix the drive side fixed pulley 632 and the drive side variable pulley 633 so that they rotate integrally, and to support the drive side variable pulley 633 so that it can slide in the axial direction of the center boss 634. The center boss 634 is disposed between the crankshaft 21a and the right crank 21c (see Figures 6A and 6B), and serves to connect the crankshaft 21a and the right crank 21c.

[0325] 34, unlike the center boss 34 (see FIG. 7) described above, the center boss 634 does not have an engagement groove 34a formed on its outer peripheral wall surface, and instead has a slide bush 635 slidably disposed therein. One end (right end) of the center boss 634 is formed with an engagement protrusion 34b having a square cross section that engages with the right crank 21c, and the other end (left end) of the center boss 634 is formed with an engagement recess 34c having a square cross section that engages with the bottom bracket 22.

[0326] The drive side slide bush 635 is mainly formed in a cylindrical shape, as shown in Figure 34, is fitted and fixed inside the drive side variable pulley 633, and slides along the axial direction of the center boss 634, allowing the drive side variable pulley 633 to slide smoothly on the center boss 634.

[0327] (Slider Housing) The slider housing 81 has a main body 81a formed in a generally cylindrical shape with a bottom, and a flange 81b extending outward from the opening edge of the main body 81a. An opening 81a1 is formed in the bottom surface of the main body 81a, and a portion of the right end of the crankshaft 21a (see FIGS. 6A and 6B) is fitted and fixed in the opening 81a1 so as to be rotatable together with the main body 81a. When the crank 21 rotates, the slider housing 81 also rotates integrally with the main body 81a. The flange 81b has sliding engagement portions 81b1 formed by U-shaped notches at predetermined locations, and a U-shaped slider 82 is attached and fixed to the sliding engagement portions 81b1. The slider 82 is formed so that its inner peripheral wall slidably engages with the ridge portion 633f3. The convex rib portion 633f3 slidably guides the sliding engagement portion 81b1 relative to the slider 82, so that the drive side variable pulley 633 can be slidably supported by the slider housing 81. The drive side variable pulley 633 is also slidably supported by the center boss 634, so that the drive side variable pulley 633 can be slidably supported at two points on the drive side fixed pulley 632 side.

[0328] In the drive unit 30 described above, the slide bush 35 slides on the center boss 34, but because the contact surface (sliding surface) has unevenness along the circumferential direction, there is a risk that the unevenness may be worn away during sliding. In contrast, in this modified example, by eliminating the unevenness on the sliding surfaces of the slide bush 634 and the center boss 635, it is possible to prevent the sliding surfaces from being worn away due to sliding.

[0329] Furthermore, in the drive unit 30 described above, the drive side variable pulley 33 is slidably supported at only one point, the contact point between the slide bush 35 and the center boss 34, which could reduce the stability of the sliding of the drive side variable pulley 33. In contrast, in this modified example, the drive side variable pulley 633 is slidably supported at two points, the slider housing 81 and the center boss 634, which makes it possible to maintain or improve the stability of the movement of the drive side variable pulley 633.

[0330] In addition, the above-mentioned drive side variable pulley 633 is equipped with a first sliding support part 91 that supports the drive side variable pulley 633 so that it can slide axially relative to the drive side fixed pulley 632, and a second sliding support part 92 that is a part different from the first sliding support part 91 and supports the drive side variable pulley 633 so that it can slide axially relative to the drive side fixed pulley 632.

[0331] The first sliding support portion 91 is a drive-side slide bush 635 formed of a cylindrical member that is press-fitted into a through-hole 633c (specifically, a first small-diameter hole portion 633c2a) that is the central through-hole of the drive-side variable pulley 633 and slides on a center boss 634 that is a cylindrical sliding sleeve portion that rotates integrally with the drive-side fixed pulley 632. The second sliding support portion 92 is a convex rib portion 633f3 that is formed along the axial direction at a position radially outward from the through-hole 633c (specifically, the first small-diameter hole portion 633c2a) that is the central through-hole of the drive-side variable pulley 633, and that is configured so that the sliding engagement portion 81b1 of the slider housing 81 that rotates integrally with the drive-side variable pulley 633 can slide.

[0332] (Drive assist unit) As shown in Figure 34, the drive assist unit 616 has an assist motor 616a, an assist drive gear 616b, an assist driven gear 616c, and a drive belt 616d. The assist motor 616a is an assist drive source that assists human power. The assist motor 616a can directly drive the wheels of the human-powered vehicle (in this modified example, the rear wheels 14).

[0333] The assist motor 616a is fixed to the lower end of the left crank plate 664. An assist drive gear 616b is provided on the output shaft 616a1 of the assist motor 616a so as to rotate integrally with the assist motor. Specifically, the assist motor 616a is threadedly attached to the left crank plate 664 by a pair of screws 616a4 each having a collar 616a3 interposed therebetween, and is threadedly attached to the left crank plate 664 by a pair of stud bolts 616a2 each having a collar 616a3 interposed therebetween. A housing plate 616i is threadedly attached to the other end of the pair of stud bolts 616a2 by nuts 616i4.

[0334] The assist driven gear 616c is assembled to a roller 616e that is capable of detachably contacting the rear wheel 14 so as to be integrally rotatable with the roller 616e, and is rotatably supported by an assist pulley plate 616f.

[0335] Specifically, the assist driven gear 616c, together with the roller 616e, is fitted onto one end of a mounting bolt 616e1 with a key 616e2 and is fastened with a nut 616e3. The other end of the mounting bolt 616e1, to which the assist driven gear 616c and roller 616e are fastened, is fastened with a nut 616e4 into a roller mounting hole 616f2 of the assist pulley plate 616f.

[0336] A drive belt 616d is installed between the assist drive gear 616b and the assist driven gear 616c, and can transmit the driving force of the assist motor 616a to the assist driven gear 616c.

[0337] The assist pulley plate 616f is formed in a dogleg shape and a plate shape, and is provided with a fulcrum hole 616f1, a roller mounting hole 616f2, and a pin mounting hole 616f3. The assist pulley plate 616f is rotatably mounted to the housing plate 616i by a pivot bolt 616g that passes through the fulcrum hole 616f1 and is screwed into a mounting hole 616i1. A pin 616h is screwed into the pin mounting hole 616f3 of the assist pulley plate 616f. One end of a spring member (not shown), the other end of which is attached to the crankcase portion 660, is attached to the pin 616h, and the roller 616e is biased toward the rear wheel 14 so as to contact the rear wheel 14.

[0338] The housing plate 616i is formed in a generally trapezoidal, plate-like shape, and is attached and fixed to the lower end of the right crank plate 663. With a distance collar 616i2 interposed between the housing plate 616i and the right crank plate 663, the distance collar 616i2 and the right crank plate 663 are screwed to the housing plate 616i with screws 616i3. The housing plate 616i is also screwed to a pair of stud bolts 616a2 with nuts 616i4.

[0339] (Crankcase section) The crankcase section 660 has the same function as the crankcase 60 described above (see FIG. 27, etc.), and is connected to the seat tube 11b (411b) and the down tube 11d (411d). The crankcase section 660 has the bottom bracket 22, which rotatably supports the crankshaft 21a, inserted and fixed therein, and can movably accommodate the shift rake 42 therein.

[0340] Crankcase portion 660 includes a shift shaft bracket 661, a left crank plate 664, and a right crank plate 663 that is arranged parallel to and facing left crank plate 664. Shift shaft bracket 661 is formed in the shape of a square plate and is interposed between the upper end of right crank plate 663 and the upper end of left crank plate 664, and is screwed to both plates 663, 664. Shift shaft bracket 661 slidably supports shift shaft 44b.

[0341] The right crank plate 663 and the left crank plate 664 are formed with through holes 663c and 664c, respectively, through which the bottom bracket 22 passes. The outer periphery of the bottom bracket 22 is connected and fixed to the right crank plate 663 and the left crank plate 664 via the through holes 663c and 664c, for example, by welding. Each of the right crank plate 663 and the left crank plate 664 also has a first mounting portion 661a that protrudes. The lower end of the seat tube 411b is screwed and fixed to the first mounting protrusion 661a. The down tube 411d is screwed and fixed to a second mounting portion (not shown) at the upper end of the right crank plate 663 and the left crank plate 664.

[0342] The right crank plate 663 is formed with a pair of openings 663a, 663b similar to the pair of openings 63a, 63b described above. One ends of a pair of guide rails 663a3a, 663a3b are connected and fixed to the opening 663a, similar to the pair of guide rails 63a3a, 63a3b (described above) that guide the guided portion 443d. The other ends of the pair of guide rails 663a3a, 663a3b are connected and fixed to the left crank plate 664. One ends of a pair of guide rails 663b3a, 663b3b are connected and fixed to the opening 663b, similar to the pair of guide rails 63b3a, 63b3b (described above) that guide the guided portion 443e. The other ends of the pair of guide rails 663b3a, 663b3b are connected and fixed to the left crank plate 664.

[0343] (Modification (Driven Part 650)) A modification of the above-mentioned driven part 50 will be described with reference to Fig. 35. As shown in Fig. 35, the driven part 650 according to the modification mainly includes a driven pulley 651, a driven slide bush (sliding metal) 656, a tension maintaining part 657 (elastic member 57a (see Fig. 10), slider housing 657b), a cassette free 58, and a mounting bolt 59.

[0344] (Driven Pulley) The driven pulley 651 is provided on the axle 14c (driven shaft) (see FIG. 2) driven by the crankshaft 21a. The driven pulley 651 has a driven fixed pulley 652 that is the fixed pulley of the driven pulley 651, and a driven variable pulley 653 that is the variable pulley of the driven pulley 651. The driven fixed pulley 652 is mounted to the hub 14a2 of the rear wheel 14 (see FIG. 2) via a cassette free 58 so as to be rotatable together with the hub 14a2. The driven variable pulley 653 is slidable along the axial direction of the sliding sleeve portion 654 of the driven fixed pulley 652 and is slidably attached to an outer peripheral wall surface 654f of one end of the sliding sleeve portion 654 of the driven fixed pulley 652 via a driven slide bush 656.

[0345] (Follower side fixed pulley) The driven side fixed pulley 652 is basically configured in the same way as the above-mentioned driven side fixed pulley 52, but differs in that both the above-mentioned sliding sleeve 54 (see Figure 10) and the first driven side slide bush 55 (see Figure 10) are integrated together.

[0346] Specifically, in the driven-side fixed pulley 652, the first driven-side slide bush 55 is integrated into the through hole 52c (see FIG. 11c ) of the driven-side fixed pulley 52, and the other end of the sliding sleeve 54 is integrated into the inner circumferential wall of the first driven-side slide bush 55. One end of the sliding sleeve 54 passes through the large-diameter hole 52c1 and protrudes toward one end. Thus, the driven-side fixed pulley 652 has a sliding sleeve portion 654 similar to the sliding sleeve 54 described above. The inner circumferential wall surface of the sliding sleeve portion 654 is provided with a plurality of (nine in this embodiment) engaging grooves 654b at predetermined intervals along the circumferential direction, similar to the engaging grooves 54b described above, and the ridges 58a of the cassette free 58 are guided and engaged with the engaging grooves 58a. The outer circumferential wall surface 654f of one end of the sliding sleeve portion 654 is free of irregularities.

[0347] (Followered Variable Pulley) The driven variable pulley 653 is basically configured in the same manner as the driven variable pulley 53 described above. In the driven variable pulley 53 described above, the inner peripheral wall surface of the inner cylindrical portion 53f of the through hole 53c is provided with a plurality of recesses 53f3. However, the inner peripheral wall surface of the inner cylindrical portion 653f of the through hole 653c2 of the driven variable pulley 653 is not formed with recesses and is formed as a flat surface (smooth surface). A cylindrical driven slide bush 656 is press-fitted and fixed into the through hole 653c2 of the driven variable pulley 653. The driven slide bush 656 allows the driven variable pulley 653 to slide smoothly on the sliding sleeve portion 654.

[0348] The driven-side variable pulley 653 has a cylindrical portion 653i extending rightward from the outer peripheral end of the pulley body 653a, which is configured similarly to the pulley body 53a described above, and protrusions 653j protruding at predetermined intervals from the cylindrical portion 653i. A plurality of (three in this embodiment) axially extending ridges 653j1 are provided at predetermined intervals along the circumferential direction on the inner wall surface of the protrusions 653j. The ridges 653j1 are slidably engaged with the sliding engagement portion 181b1 of the slider housing 657b via the slider 182. The slider housing 181 is housed within the driven-side variable pulley 653 in a rotationally restricted manner (rotatable integrally) and axially slidable manner.

[0349] (Tension Maintaining Unit) The tension maintaining unit 657 functions in the same manner as the tension maintaining unit 57 described above, and has a coil spring 57a and a slider housing 657b that functions in the same manner as the retainer spring 57b to which the other end of the coil spring 57a is attached, and that functions in the same manner as the slider housing 81 described above. The coil spring 57a is interposed between the driven-side variable pulley 653 and the slider housing 181. One end of the coil spring 57a is attached to the driven-side variable pulley 653, and the other end of the coil spring 57a is attached to the slider housing 181.

[0350] Similar to the slider housing 81 described above, the slider housing 657b (181) has a main body 181a formed in a generally cylindrical shape with a bottom, and a flange 181b extending outward from the opening edge of the main body 181a. An opening 181a1 is formed in the bottom surface of the main body 181a, through which the mounting bolts 59 can be inserted. The flange 181b has sliding engagement portions 181b1 formed by U-shaped notches at a plurality of predetermined locations, to which a U-shaped slider 182 is attached and fixed. The slider 182 has an inner peripheral wall slidably engaged with the ridge portion 653j1. The ridge portion 653j1 slidably guides the sliding engagement portion 181b1 relative to the slider 182, thereby allowing the driven-side variable pulley 653 to be slidably supported by the slider housing 181. The driven variable pulley 653 is also slidably supported by the sliding sleeve portion 654, so that the driven variable pulley 653 can be slidably supported on the driven fixed pulley 652 at two points.

[0351] In addition, the above-mentioned driven side variable pulley 653 is equipped with a first sliding support part 191 that supports the driven side variable pulley 653 so that it can slide axially relative to the driven side fixed pulley 652, and a second sliding support part 192 that is a part different from the first sliding support part 191 and supports the driven side variable pulley 653 so that it can slide axially relative to the driven side fixed pulley 652.

[0352] The first sliding support portion 191 is a driven-side slide bush 656 made of a cylindrical member that is press-fitted into a through hole 653c2 that is the central through hole of the driven-side variable pulley 653 and slides on a sliding sleeve portion 654 that is a cylindrical sliding sleeve portion that rotates integrally with the driven-side fixed pulley 652. The second sliding support portion 192 is a convex ridge portion 653j1 that is formed along the axial direction at a position radially outward from the through hole 653c2 that is the central through hole of the driven-side variable pulley 653, and that is configured so that the sliding engagement portion 181b1 of the slider housing 181 that rotates integrally with the driven-side variable pulley 653 can slide.

[0353] (Effects of the embodiments and variations) The bicycle 10 (human-powered vehicle equipped with a continuously variable transmission) according to the above-described embodiment is a human-powered vehicle equipped with a drive pulley 31, 131, 231 provided on the crankshaft 21a (drive shaft), a driven pulley 51 provided on the axle 14c (driven shaft) driven by the crankshaft 21a, and a V-belt 23c (transmission member) that is mounted on the drive pulley 31, 131, 231 and the driven pulley 51 and transmits the human power applied to the crankshaft 21a to the axle 14c, and is also equipped with a continuously variable transmission 23, 223 that changes the speed of the axle 14c. The drive side pulley 31, 131, 231 and the driven side pulley 51 each include a variable pulley and a fixed pulley, and the bicycle 10 further includes a speed change adjustment unit 38, 238 that automatically moves the drive side variable pulley 33, 133, 233, which is the variable pulley of the drive side pulley 31, 131, 231, relative to the drive side fixed pulley 32, 132, 232, which is the fixed pulley of the drive side pulley 31, 131, 231, along the axial direction of the crankshaft 21a, thereby adjusting the speed change.

[0354] According to this embodiment, the speed adjustment unit 38, 238 can automatically change speeds, making it possible to provide a bicycle 10 equipped with a continuously variable speed change device 23, 223 that can automatically change speeds.

[0355] In addition, in a bicycle 10 equipped with a continuously variable transmission 23, 223 according to this embodiment, the speed adjustment unit 38, 238 includes a cam mechanism 41, 241 having a cam 41a, 241a that rotates or moves linearly, a follower 41b, 241b that is linearly moved by the cam 41a, 241a and can relatively move the drive variable pulley 33, 133, 233, and a speed change motor 44a, 244a (speed change drive source) that drives the cam 41a, 241a to relatively move the drive variable pulley 33, 133, 233. This allows the drive variable pulley 33, 133, 233 to be automatically moved with a relatively simple structure.

[0356] Furthermore, in a bicycle 10 equipped with the continuously variable transmission 23, 223 according to this embodiment, the cam mechanism 41, 241 and the gear change motor 44a, 244a are arranged along the frame 11 (down tube 11d in this embodiment) that supports the crankshaft 21a. This allows the cam mechanism 41, 241 and the gear change motor 44a, 244a, i.e., the gear change adjustment unit 38, 238, to be positioned optimally so as not to interfere with the rider's operation.

[0357] In addition, in a bicycle 10 equipped with a continuously variable transmission 23, 223 according to this embodiment, the speed change adjustment unit 38, 238 includes a cam mechanism 41, 241 having a cam 41a, 241a that moves linearly in a first direction, a push plate 43a, 443a that moves linearly in a second direction different from the first direction and that can press against the drive side variable pulley 33, 133, 233, and a follower 41b, 241b connected to a shift fork 243a (pressing member), and a speed change motor 44a, 244a that drives the cam 41a, 241a to move the drive side variable pulley 33, 133, 233 relative to the cam 41a, 241a. This allows the cam mechanism 41, 241 to be formed relatively simply and with high durability, and the speed change adjustment unit 38, 238 to be formed relatively simply and with high durability.

[0358] In addition, in a bicycle 10 equipped with the continuously variable transmission 23, 223 according to this embodiment, the cam mechanism 41, 241 has a cam main body 42b, 42c, 342b, 342c (main body) whose base end is connected to the output shaft 44a1, 244a1 of the transmission motor 44a, 244a and which moves linearly along the first direction, and a push plate 43a, 443a and a shift fork 243a which are capable of pressing the drive side variable pulley 33, 133, 233 along the second direction, and the cam 41a, 241a is provided on the cam main body 42b, 42c, 342b, 342c, and the follower 41b, 241b is provided in a protruding manner along the second direction on the push plate 43a, 443a and the shift fork 243a. This allows the cam mechanism 41, 241 to be formed more simply and with high durability, and the speed change adjusting portion 38, 238 to be formed more simply and with high durability.

[0359] Furthermore, in bicycle 10 equipped with continuously variable transmission 23, 223 according to this embodiment, cam body 42b, 42c, 342b, 342c is tapered, and cam 41a, 241a is provided on inclined surface 42d1, 42e1, 342d1 formed on cam body 42b, 42c, 342b, 342c at a predetermined angle with respect to the first direction. This allows cam mechanism 41, 241 to be formed more simply and with high durability.

[0360] Furthermore, in the bicycle 10 equipped with the continuously variable transmission 23, 223 according to this embodiment, the inclined surface 342d1 is formed into a predetermined curved surface, either concave or convex, so that the follower 41b, which is moved linearly by the cam 41a, can be moved linearly in the desired manner.

[0361] Furthermore, in bicycles 10 equipped with continuously variable transmissions 23, 223 according to this embodiment, the cam mechanisms 41, 241 and gear-shifting motors 44a, 244a are disposed within the frame 411. This allows the cam mechanisms 41, 241 and gear-shifting motors 44a, 244a, i.e., the gear-shift adjustment units 38, 238, to be disposed in optimal locations that do not interfere with the rider's operation.

[0362] Furthermore, in bicycle 10 equipped with continuously variable transmission 23, 223 according to this embodiment, frame 411 includes crankcase 60 that rotatably houses crankshaft 21a and can house cam mechanism 41, 241. This allows cam mechanism 41, 241 to be housed within crankcase 60, i.e., frame 411, and allows cam mechanism 41, 241 and transmission motor 44a, 244a to be housed within frame 411 with a simple structure, while also improving design.

[0363] In addition, in the bicycle 10 equipped with the continuously variable transmission 23, 223 according to this embodiment, the drive-side variable pulley 133 and the drive-side fixed pulley 132 face each other, are relatively movable in the axial direction, and are engageable with each other, and have generally fan-shaped protrusions 132e, 133e and generally fan-shaped recesses 132d, 133d that are engageable with the protrusions 132e, 133e, respectively. The friction surfaces of the protrusions 132e, 133e that contact the V-belt 23c (third side wall surfaces 132e5, 133e5) are formed with fan-shaped recesses 132e5b, grooves 133e5a (friction surface recesses), and / or ridges 132e5a and fan-shaped protrusions 133e5b (friction surface protrusions). This maintains a high frictional force with the V-belt 23c, thereby maintaining high transmission efficiency.

[0364] Furthermore, in a bicycle 10 equipped with the continuously variable transmission 23, 223 according to this embodiment, the fixed drive pulley 32, 132, 232 is fitted and fixed to one end of the center boss 34, and the variable drive pulley 33, 133, 233 is assembled onto the center boss 34 via a drive slide bush 35 (slide bush) so that it is rotationally restricted and axially slidable. This allows the fixed drive pulley 32, 132, 232 and the variable drive pulley 33, 133, 233 to be assembled onto the center boss 34 in advance to form sub-units, making it possible to assemble the drive pulley 31, 131, 231 easily and accurately.

[0365] Furthermore, in a bicycle 10 equipped with the continuously variable transmission 23, 223 according to this embodiment, the drive side variable pulley 33, 133, 233 and the drive side fixed pulley 32, 132, 232 each have a roughly fan-shaped convex portion 32e, 33e, 132e, 133e and a roughly fan-shaped concave portion 32d, 33d, 132d, 133d that can mesh with the convex portion 32e, 33e, 132e, 133e, and the bottom surface of the concave portion 32d, 33d, 132d, 133d has a recess 32h, 33h, 133h formed corresponding to the meshing convex portion 32e, 33e, 132e, 133e. This allows the strength of the bottom side to be maintained high by leaving the bottom surfaces of the recesses 32d, 33d, 132d, 133d intact, and when the drive side variable pulley 33, 133, 233 and the drive side fixed pulley 32, 132, 232 are closed, the convex portions 32e, 33e, 132e, 133e enter the recesses 32h, 33h, 133h, so the thickness of the drive side pulley 31, 131, 231 can be kept small.

[0366] Furthermore, in bicycle 10 equipped with continuously variable transmission 23, 223 according to this embodiment, driven fixed pulley 52, which is the fixed pulley of driven pulley 51, is fitted and fixed to one end of sliding sleeve 54, and driven variable pulley 53, which is the variable pulley of driven pulley 51, is assembled onto sliding sleeve 54 via second driven slide bush 56 (slide bush) so as to be rotationally restricted and axially slidable. In this way, by assembling driven fixed pulley 52 and driven variable pulley 53 to center boss 34 in advance to form a sub-unit, assembly of driven pulley 51 can be simplified and accurate.

[0367] Furthermore, in a bicycle 10 equipped with a continuously variable transmission 23, 223 according to this embodiment, the bicycle 10 further includes a tension maintaining unit 57 that maintains the tension of the V-belt 23c by moving the variable driven pulley 53, which is the variable pulley of the driven pulley 51, relative to the fixed driven pulley 52, which is the fixed pulley of the driven pulley 51, along the axial direction of the axle 14c, and the tension maintaining unit 57 has a coil spring 57a (biasing member) that biases the variable driven pulley 53 toward the fixed driven pulley 52. ​​This allows the tension maintaining unit 57 to be formed with a relatively simple structure.

[0368] Furthermore, in the bicycle 10 equipped with the continuously variable transmission 23, 223 according to this embodiment, the biasing member is a coil spring, which allows the tension maintaining section 57 to be formed with a simpler structure.

[0369] In addition, in a bicycle 10 equipped with the continuously variable transmission 23, 223 of this embodiment, the drive side variable pulley 633 or the driven side variable pulley 653 is provided with a first sliding support part 91 or 191 that supports the drive side variable pulley 633 or the driven side variable pulley 653 so that it can slide in the axial direction relative to the drive side fixed pulley 632 or the driven side fixed pulley 652, and a second sliding support part 92 or 192 that is a part different from the first sliding support part 91 or 191 and supports the drive side fixed pulley 632 or the driven side fixed pulley 652 so that it can slide in the axial direction relative to the drive side fixed pulley 632 or the driven side fixed pulley 652. This makes it possible to slidably support the drive-side variable pulley 633 or the driven-side variable pulley 653 relative to the drive-side fixed pulley 632 or the driven-side fixed pulley 652 at two points (two locations), the first sliding support portion 91 or 191 and the second sliding support portion 92 or 192, and therefore makes it possible to slidably support the drive-side variable pulley 633 or the driven-side variable pulley 653 without tilting in the axial direction (and consequently the drive-side fixed pulley 632 or the driven-side fixed pulley 652). Therefore, it is possible to prevent unnecessary wear due to sliding between the drive-side variable pulley 633 or the driven-side variable pulley 653 and the drive-side fixed pulley 632 or the driven-side fixed pulley 652.

[0370] In addition, in the bicycle 10 equipped with the continuously variable transmission 23, 223 according to this embodiment, the first sliding support portion 91 or 191 is press-fitted into the through hole 633c (center through hole) of the driving side variable pulley 633 or the through hole 653c (center through hole) of the driven side variable pulley 653, and slides on the cylindrical center boss 634 or sliding sleeve portion 654 (sliding sleeve portion) that rotates integrally with the driving side fixed pulley 632 or the driven side fixed pulley 652. The second sliding support portion 92 or 192 is configured as a cylindrical member, and is a convex rib portion formed along the axial direction at a position radially outward from the through hole 633c (center through hole) of the driving side variable pulley 633 or the through hole 653c (center through hole) of the driven side variable pulley 653, and is configured to allow sliding of the sliding engagement portion 81b1 or 181b1 of the slider housing 81 or 181 that rotates integrally with the driving side variable pulley 633 or the driven side variable pulley 653. This makes it possible to reliably slidably support the driving side variable pulley 633 or the driven side variable pulley 653 at two points (two locations) with a simple configuration.

[0371] In the above-described embodiment and modified examples, the cam mechanism 41, 241 and the gear shift drive source 44a, 244a are arranged along the down tube 11d that supports the crankshaft 21a, or arranged inside the down tube 411d that supports the crankcase 60, but the cam mechanism 41, 241 and the gear shift drive source 44a, 244a may also be arranged along another frame that supports the crankshaft 21a, such as the seat tube 11b, or arranged inside the seat tube 411b that supports the crankcase 60. In this case, it is preferable that the seat tube 411b has a bifurcated tip similar to the down tube 411d.

[0372] Furthermore, the present invention is not limited to the above-described embodiments and modifications, but can be implemented in various forms with various changes and improvements made based on the knowledge of those skilled in the art.

[0373] 10...Bicycle (human-powered vehicle equipped with continuously variable transmission), 11,411...Frame (down tube 11d, 411d), 14c...Axle (driven shaft), 21a...Crankshaft (drive shaft), 23,223...Continuously variable transmission, 23c...V-belt (transmission member), 31,131,231,631...Driving-side pulley, 32,132,232,632...Driving-side fixed pulley, 32d,33d,132d,133d...Approximately sector-shaped concave portion, 32e,33e,132e,133e...Approximately sector-shaped convex portion portion, 32h, 33h, 133h...relief portion, 33, 133, 233, 633...driving side variable pulley, 38, 238...speed change adjustment portion, 34, 634...center boss, 35, 635...driving side slide bush (slide bush), 41, 241...cam mechanism, 41a, 241a...cam, 41b, 241b...follower, 42b, 42c, 342b, 342c...cam main body portion (main body portion), 42d1, 42e1, 342d1...inclined surface, 43a, 443a...push plate (pressing member), 243a...shift fork (pressing member), 44a, 244a...speed-changing motor (speed-changing drive source), 51, 651...driven pulley, 52, 652...driven fixed pulley, 53, 653...driven variable pulley, 54...sliding sleeve, 56, 656...second driven slide bush (slide bush), 57...tension maintaining portion, 57a...coil spring (urging member), 60...crankcase, 81, 181...slider housing, 81b 1, 181b1...sliding engagement portion, 91, 191...first sliding support portion, 92, 192...second sliding support portion, 132e5, 133e5...third side wall surface, 132e5b...fan-shaped recess (friction surface side recess), 133e5a...groove portion (friction surface side recess), 132e5a...convex ridge portion (friction surface side convex portion), 133e5b...fan-shaped convex portion (friction surface side convex portion), 633c, 653c...through hole (central through hole), 634...center boss (sliding sleeve portion), 654...sliding sleeve portion.

Claims

1. A manpowered vehicle equipped with a continuously variable transmission comprising: a drive side pulley provided on a drive shaft; a driven side pulley provided on a driven shaft driven by the drive shaft; and a transmission member mounted on the drive side pulley and the driven side pulley for transmitting human power applied to the drive shaft to the driven shaft, and further comprising a speed change adjustment unit which adjusts the speed by automatically moving the drive side variable pulley, which is the variable pulley of the drive side pulley, relative to the drive side fixed pulley, which is the fixed pulley of the drive side pulley, along the axial direction of the drive shaft.

2. A human-powered vehicle equipped with a continuously variable transmission as described in claim 1, wherein the speed change adjustment section comprises: a cam mechanism having a cam that rotates or moves linearly, and a follower that is moved linearly by the cam and can move the drive side variable pulley relatively; and a speed change drive source for driving the cam to move the drive side variable pulley relatively.

3. A human powered vehicle equipped with a continuously variable transmission as described in claim 1, wherein the speed change adjustment section comprises: a cam mechanism having a cam that moves linearly along a first direction, and a follower that moves linearly along a second direction different from the first direction and is connected to a pressing member that can press the drive side variable pulley; and a speed change drive source that drives the cam to move the drive side variable pulley relatively.

4. A human-powered vehicle equipped with a continuously variable transmission as described in claim 3, wherein the cam mechanism has a main body portion whose base end is connected to the output shaft of the speed-changing drive source and moves linearly along the first direction, and a pressing member capable of pressing the drive side variable pulley along the second direction, the cam is provided on the main body portion, and the follower is provided on the pressing member in a protruding manner along the second direction.

5. A human-powered vehicle equipped with a continuously variable transmission as described in claim 4, wherein the main body portion is tapered, and the cam is an inclined surface formed on the main body portion at a predetermined angle with respect to the first direction.

6. A human-powered vehicle equipped with a continuously variable transmission as claimed in claim 5, wherein the inclined surface is formed into a predetermined concave or convex curved surface.

7. A human-powered vehicle equipped with a continuously variable transmission as described in claim 1, wherein the driving side variable pulley and the driving side fixed pulley face each other, are relatively movable along the axial direction and can mesh with each other, and each have a roughly fan-shaped convex portion and a roughly fan-shaped concave portion that can mesh with the convex portion, and a friction surface side concave portion and / or a friction surface side convex portion is formed on the friction surface side of the convex portion with the transmission member.

8. A human-powered vehicle equipped with a continuously variable transmission as described in claim 7, wherein the driving side fixed pulley is fitted and fixed to one end of the center boss, and the driving side variable pulley is assembled on the center boss via a slide bush so as to be rotationally restricted and axially slidable.

9. A human-powered vehicle equipped with a continuously variable transmission as described in claim 8, wherein the drive side variable pulley and the drive side fixed pulley each have a substantially fan-shaped convex portion and a substantially fan-shaped concave portion capable of meshing with the convex portion, and a clearance portion is formed on the bottom surface of the concave portion corresponding to the convex portion that meshes with the concave portion.

10. A human-powered vehicle equipped with a continuously variable transmission as described in claim 7, wherein the fixed pulley of the driven pulley is fitted and fixed to one end of a sliding sleeve, and the variable pulley of the driven pulley is assembled on the sliding sleeve via a slide bush so as to be rotationally restricted and axially slidable.

11. A human-powered vehicle equipped with a continuously variable transmission as described in claim 1, wherein the variable pulley is provided with: a first sliding support portion that supports the variable pulley so that it can slide in the axial direction relative to the fixed pulley; and a second sliding support portion that is a portion different from the first sliding support portion and supports the variable pulley so that it can slide in the axial direction relative to the fixed pulley.

12. A human-powered vehicle equipped with a continuously variable transmission as described in claim 11, wherein the first sliding support portion is composed of a cylindrical member that is pressed into the central through hole of the variable pulley and slides on a cylindrical sliding sleeve portion that rotates integrally with the fixed pulley, and the second sliding support portion is a convex rib portion formed along the axial direction at a position radially outward from the central through hole of the variable pulley, and is configured so that a sliding engagement portion of a slider housing that rotates integrally with the variable pulley can slide.

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