JPH0228512B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a continuously variable transmission device suitable for being mainly installed on the crankshaft of a bicycle.

(Prior Art) Conventional bicycle transmissions include a chain changeable transmission, a gear type stepped transmission, a continuously variable belt transmission, and a non-rotating cam disclosed in Japanese Patent Application Laid-Open No. 54-93754. There are continuously variable transmissions and the like.

(Problems to be Solved by the Invention) However, the above-mentioned chain changeable and gear type stepped transmissions cannot be used as continuously variable transmissions, and belt type continuously variable transmissions have large transmission losses and the time required for shifting. It also takes a long time to shift, and it also has the disadvantage that it is impossible to change gears instantaneously in an emergency.

Furthermore, the continuously variable transmission with a non-rotating cam disclosed in Japanese Patent Application Laid-open No. 54-93754 uses a planetary gear device with an internal crank ring to increase speed, and its speed increase ratio depends on the diameter of the planetary gear, It is determined by the ratio of the diameters of the sun gears, and the transmission force has a property that the more planetary gears are used, the smaller the pulsation becomes.

However, due to the structure of this device, there is a problem in that the speed ratio cannot be varied widely, and since there is a limit to the number of planetary gears that can be used, there is also a problem in that the pulsation of the transmission force cannot be reduced beyond a certain level. It was hot.

The present invention was made in order to solve the above-mentioned problems, and it has a small transmission loss, allows shifting while stopped and running, and can widen the variation range of the gear ratio, and can reduce the pulsation of the transmission force. It is an object of the present invention to provide a continuously variable transmission that can be made extremely small.

(Means for Solving the Problems) In order to solve the above-mentioned problems, in the present invention, a disc-shaped carrier having a plurality of planetary gears supported on the end of the bicycle crankshaft is fixed to the end of the crankshaft of the bicycle. A sun gear that meshes with the planetary gear is rotatably provided in the middle part of the sun gear, an eccentric cam whose eccentricity can be freely adjusted with respect to the crankshaft is rotatably provided in the cylindrical part of the sun gear, and both sides of the eccentric cam are rotatably provided. Surrounded by two bases that are locked to the fixed member during normal rotation,
An internal gear carved on the inner periphery of the outer base is meshed with the planetary gear, and between the outer peripheries of the two bases,
An output driven ring with a ratchet on the inner circumferential surface is rotatably provided, one end of the bell crank is pivoted between the two bases, and a corner of the bell crank is attached to the outer circumference of the eccentric cam. A plurality of accelerators are disposed between the eccentric cam and the driven ring, the claws of which are pivotally supported on the other end of the bell crank are brought into elastic contact with the ratchets of the driven ring. Configure the transmission.

(Function) Since the device of the present invention is configured as described above, chain transmission is possible by integrally forming a sprocket on the output driven ring. Therefore, transmission losses caused by slips in conventional belt transmission type transmissions can be eliminated.

Furthermore, due to its structure, the device of the present invention allows a speed change operation to be carried out effortlessly and reliably even when the vehicle is stopped or when the vehicle is running, and the speed change operation is extremely easy.

Furthermore, when compared with a conventional transmission using a planetary gear with an internal crank ring, the device of the present invention changes speed simply by an accelerator that makes an oscillating motion, and this accelerator is different from the conventional planetary gear. Since a much larger number (approximately twice) can be provided, the pulsation of the transmission force can be reduced accordingly.

In addition, the oscillating motion range of the accelerator, which determines the magnitude of the transmission speed, is structurally possible from 0° to approximately 100°, so the range of variation in the gear ratio is significantly expanded compared to that using conventional planetary gears. Can be done.

(Embodiment) An embodiment in which the present invention is applied to a continuously variable transmission for a bicycle will be described below with reference to the drawings. In the figure, 1 (see Figure 3) is the main pipe of the bicycle frame, 3 is a vertical pipe, 3 is a chain stay, 4 is a hanger rack, 5 is a crankshaft (drive shaft), 6 is a crank arm that fits on the crankshaft 5, 7 is its rock night and 8 is its chain.

Reference numeral 9 denotes a disc-shaped carrier (see Fig. 4) that is fixed integrally with the crank arm 6, and a plurality of (four in this embodiment) shafts 10 on the same circumference of the carrier 9 are connected to each other.
are arranged, and a planetary gear 1 is attached to each of these shafts 10.
1 is rotatably fitted. Further, 12 is a bare cylinder fitted to the outer circumferential portion of the carrier 9.

Reference numeral 13 denotes a sun gear which is rotatably fitted to the crankshaft 5 via a bare cylinder 14 so as to mesh with the planetary gear 11. Adjacent to this sun gear 13 is a disc-shaped flange 13a (see FIG. 4). ) is formed integrally with the flange 13a, and a long hole 13b extending in the radial direction is provided in the flange 13a. Further, a cylindrical shaft portion 13c is integrally formed following the flange 13a, and a stepped small diameter portion 13d is formed at the end of the cylindrical shaft portion 13c.

Reference numeral 15 designates an inner eccentric cam that rotatably fits into the shaft cylindrical portion 13c of the sun gear 13. Adjacent to this cam 15, a cylindrical portion 15a concentric with the crankshaft 5 is integrally formed. Reference numeral 16 denotes an outer eccentric cam that is rotatably fitted to the outer circumference of the inner eccentric cam 15. One side of this cam 16 is slidably fitted into an elongated hole 13b provided in the flange 13a of the sun gear 13. A protrusion 16a is provided in a protruding manner. 17 is a bearing fitted on the outer periphery of the cam 16.

Further, 18 has an internal gear 18a that fits into the outer circumference of the bearing 12 disposed on the outer circumference of the carrier 9 and meshes with each of the four planetary gears 11.
Furthermore, a base A is integrally formed with a flange portion 18b that loosely fits into the outer peripheral portion of the flange 13a of the sun gear 13, and 19 is a base plate A that is integrally formed with a flange portion 18b that fits loosely into the outer peripheral portion of the flange 13a of the sun gear 13.
The base B has a hollow disc part 19a that fits into the outer peripheral part of the bearing 20 fitted in the ring-shaped outer peripheral part, and has a ratchet 21a for the one-way clutch 21 formed on the inner peripheral surface of the ring-shaped outer peripheral part. Foundation 1
8 and 19 surround both sides of the eccentric cams 15 and 16.

Further, a differential gear A22 is fixed to the end surface of the cylindrical portion 15a integral with the inner eccentric cam 15 with a screw 22a (see FIG. 3), and a differential gear B23 having the same diameter is adjacent to the differential gear A22. But sun gear 13
The stepped small diameter portion 13d is fixed to the stepped small diameter portion 13d. Reference numeral 24 designates a hollow disc-shaped differential frame (see FIG. 3) that fits inside the ratchet 21a of the base plate B19, and this differential frame 24 is fixed to the hanger rack 4 (vehicle body). A pawl 21b for the one-way clutch 21, which engages with the ratchet 21a, is provided on the outer peripheral surface of the frame 24 and is always biased by a spring 21c in the direction of meshing with the ratchet 21a. Further, a ring-shaped internal gear 25 is rotatably fitted inside the ring-shaped outer peripheral portion of the differential frame 24, and a wire reel 26 is rotatably fitted on the side surface of the differential frame 24 on the vehicle body side. The equipment is installed in 27 is a ring-shaped plate for holding the wire reel 26 on the differential frame 24, and 28 (see FIG. 3) is a set screw thereof. 29 is an inner wire wound around the wire reel 26, and 30 is its outer wire.

In addition, a plurality of (three in this embodiment) shafts 31 are protruded from the plate-shaped portion of the differential frame 24 at equal positions on the circumference, and the differential gear B3 is connected to these shafts 31.
The ring-shaped internal gear 2 externally meshes with the ring-shaped internal gear 2.
A planetary gear 32 which is internally meshed with 5 is rotatably fitted in each case. Further, 24a is an arcuate long hole formed in the differential frame 24 between the shafts 31, 33 is a shaft protruding from the side surface of the wire reel 26 so as to pass through these long holes 34a, and 34 is a shaft that protrudes from the side surface of the wire reel 26 so as to pass through these long holes 34a. The planetary gears 34 are rotatably fitted onto the shaft 33, and each planetary gear 34 externally meshes with the differential gear A22 and internally meshes with the internal gear 25.

35 has a substantially U-shaped cross section, and
An output driving ring with a sprocket 36 integrally formed on one side thereof, which connects the base A18 and base B19.
It is rotatably fitted on the outer periphery of the bearing via a bearing (a large number of steel balls) 37.

Two ratchet rings 38, each having a ratchet 38b formed on the inner periphery of a bevel gear 38a, are rotatably arranged in parallel in the recess on the inner periphery of the output driven ring 35. A plurality of bevel gears 39 (five in this embodiment, see FIG. 2) meshing with the bevel gears 38a of the two ratchet rings 38 are pivoted to the output driving ring 35 via a shaft 40. It has been done. 41 is its Rocknight.

In addition, two plate-shaped bell cranks 42 are opposed to each other with the bearing 17 and the outer eccentric cam 16 in between to form a set of bell cranks, and one end of the bell cranks 42 is connected to the left and right bases A18 and A roller 44 which is pivoted to the base B19 and connected to a bearing 17 at a corner of the bell crank 42 is pivoted by a shaft 45, and a pawl 47 which is pivoted by a shaft 46 is attached to the other end of the bell crank 42 by a driven ring 35. The accelerator 49 is configured such that it is always brought into elastic contact with either one of the ratchets 38b by a coil spring 48 fitted to a shaft 46.

As shown in FIG. 2, a plurality of accelerators 49 (10 in this embodiment) are arranged between the bearing 17 and the ratchet 38b, and the claws 47 of adjacent accelerators 49 are arranged alternately on the left and right. They are arranged to come into elastic contact alternately with the left and right ratchets 38b, respectively.

In addition, collars 51 each fitted with a coil spring 50 (see FIGS. 2 and 4) are inserted between the left and right bases 18 and 19 in the spaces between adjacent accelerators 49,
The screw 52 inserted through the hole 19b of the base B19 passes through the collar 51 to the screw hole 18 provided in the base A18.
By screwing into the left and right bases 18 and 19
At the same time, one end 50a of the coil spring 50 is secured to the base A18, and the other end 50a is secured to the base A18.
0b is the axis 45 of the roller 44 as shown in FIG.
By pressing the roller 44 against the bearing 17, the roller 44 is always in elastic contact with the bearing 17.

Note that 18d in FIG. 4 is a shaft hole of the pivot shaft 43 of the accelerator 49 provided in the base A18;
c is a shaft hole provided in the base B19.

Next, the operation of the continuously variable transmission of the present invention constructed as described above will be explained.

First, to explain the speed change operation, when the inner wire 29 shown in FIGS. 3 and 6 is moved in the direction of arrow D by operating the speed change lever (not shown) attached to the bicycle, the wire reel 26 shown in FIG. Since the shaft 33 rotates in the direction of arrow E, the shaft 33 also rotates in the direction of arrow E. In this case, if the bicycle is stopped, the crankshaft 5, crank arm 6,
The carrier 9, planetary gear 11, sun gear 13, differential gear B23, planetary gear 32, and internal gear 25 are all stopped.

Therefore, when the shaft 33 moves in the direction of the arrow E, the planetary gear 34 rotates in the direction of the arrow E in FIG. 6, causing the differential gear A22 meshing therewith to rotate in the direction of the arrow E.

The differential gear A22 is fixed to the inner eccentric cam 15, and the outer eccentric cam 16 is fixed to the protrusion 16.
(a) Since it is connected to the stopped sun gear 13 via the elongated hole 13b, if the inner wire 29 moves, the inner eccentric cam 15 will move differentially with respect to the outer eccentric cam 16.

7 and 9 show the case where the outer eccentric cam 16 is in the maximum eccentric state as a result of the above-described operation.

Next, when the inner wire 29 is operated in the direction of arrow G in the opposite direction, the wire reel 26 and the shaft 3
3 rotates in the direction of arrow H, the planetary gear 34
rotates in the direction of arrow I, causing differential gear A22 to rotate in the direction of arrow H. Therefore, the inner eccentric cam 15 rotates in the direction of arrow I in FIG.
When rotated approximately θ° as shown in the figure, the outer eccentric cam 1
6 is the minimum eccentric state in this embodiment.

Since this embodiment is a continuously variable transmission for a bicycle, the maximum eccentricity (the state shown in FIG. 7) and the minimum eccentricity (the state shown in FIG. 8) of the outer eccentric cam 16 may be at this level; If the structure has a maximum eccentricity, it can be increased, and the minimum eccentricity can easily be set to zero.

Also, for convenience, the above gear shifting operation has been explained for the case where the bicycle is stopped, but the above gear shifting operation is possible even when the bicycle is running.
According to this, the gear shifting operation can be performed easily and reliably even when the vehicle is stopped or while the vehicle is running, which is extremely convenient.

Next, the transmission operation of this continuously variable transmission will be explained.

When the crankshaft (drive shaft) 5 is rotated via the crank arm 6, the carrier 9 rotates together with the crank arm 6 as shown by arrow J in FIG. Therefore, since the shaft 10 also revolves in the direction of arrow J, if there is rotational resistance in the sun gear 13,
The base A18 also tries to rotate in the direction of arrow J, but this rotation in the direction of arrow J is as shown in Fig. 6 (arrow J is in the opposite direction as it is viewed from the opposite direction to Fig. 5). Ratchet 21a and claw 21b
This is prevented by the action of a one-way clutch 21 consisting of:

Therefore, when the carrier 9 and the shaft 10 rotate in the direction of the arrow J in FIG.
a and the planetary gear 11, the planetary gear 11
rotates in the direction of arrow K, and the sun gear 13 rotates in the direction of arrow K.
rotates in the direction of arrow L at increased speed from the crankshaft 5.

When the sun gear 13 rotates, the outer eccentric cam 16 rotates in the direction of the arrow L through the elongated hole 13b of the flange 13a and the projection 16a, and the rotation of the differential gear B23 causes the rotation of the planetary gear 32 and the internal gear 2.
5. The planetary gears 32, 34 are transmitted to the inner eccentric cam 15 via the planetary gear 34 and the differential gear A22.
The outer eccentric cam 16 and the inner eccentric cam 15 rotate integrally unless the phase between them changes, that is, unless the wire reel 26 is rotated by operating the inner wire 29.

As described above, FIG. 7 shows the state of the outer eccentric cam 16 in this embodiment at the maximum eccentricity, so in this state, the outer eccentric cam 16 and the inner eccentric cam 15 move as shown in FIG. When rotating in the direction of arrow L, accelerator 4 in the state shown in the left half
9 is in the state shown by the dotted line. At this time, the pawl 47 meshes with the ratchet 38b in the output driving ring 35 at point M.

When the cams 15 and 16 rotate 180 degrees from this state, the state shown in the right half of FIG. Since the accelerator 49 is in elastic contact with the surface due to the action of the coil spring 50, the accelerator 49 rotates about the pivot shaft 43 from the position shown by the dotted line to the position shown by the solid line. As a result, the engagement point between the pawl 47 and the ratchet 38b moves from M to N by _l1 . That is, the output driving ring 35 is rotationally driven in the direction of arrow O by the movement of the _l1 claw.

Therefore, 10 accelerators 49 are arranged on the circumference, and since these 10 accelerators 49 rotate the driving ring 35 one by _one in turn, the driving ring 3
5 rotates continuously.

Furthermore, as described above, FIG. 8 shows the state of the outer eccentric 16 in this embodiment at its minimum eccentricity, so in this state, the outer eccentric cam 16 and the inner eccentric cam 15 move as shown in FIG. When rotated in the direction of arrow L, the accelerator 49 changes to the state shown by the dotted line in the state shown in the left half. At this time, the pawl 47 meshes with the ratchet 38b of the output driven ring 35 at point P.

When the cams 15 and 16 rotate 180 degrees from this state, the accelerator 49, which is in the state shown in the right half of FIG. 10, rotates about the pivot shaft 43 from the position shown by the dotted line to the position shown by the solid line. As a result, the engagement point between the pawl 47 and the ratchet 38b moves from P to Q by _l2 . That is, the output driving ring 35 is rotationally driven by the movement of the _l2 claw.

As mentioned above, when the cam is at maximum eccentricity, the cam rotates by l ₁ every half rotation, and when it is at minimum eccentricity, it rotates by l ₂ , so this l ₁ /l ₂ becomes the variation width (variation magnification) of the gear ratio. In the case of this embodiment, l ₁ /l ₂ ≒2.5, but as mentioned above, in the device of the present invention, the minimum eccentricity of the cam can be easily set to 0, so the variation magnification of this gear ratio is It can be increased to infinity if necessary. Therefore, the continuously variable transmission device of the present invention has the advantage that the variable magnification of the gear ratio can be increased as necessary.

Next, the pulsation buffering effect will be explained. As mentioned above, even if the ratchet 38b with which the claw 47 of the accelerator 49 engages is formed integrally with the output driven ring 35, this device will of course operate differentially. In the case of 10 accelerators 49, only the one that operates the driven ring 35 at the fastest speed drives the driven ring 35,
The pawl 47 of the other accelerator 49 will slide against the ratchet 38b. However, accelerator 49
Strictly speaking, the driving action of the pawl 47 is not at a constant speed within the above-mentioned range l ₁ or l ₂ even if the rotation of the crankshaft 5 is at a constant speed. However, in the present invention, since a large number of accelerators 49 (10 in this embodiment) are provided, the large number of accelerators 49 act on the driven ring 3 in turn.
As a result of driving 5, the pulsation caused by the above-mentioned non-uniform speed can be greatly reduced.

Further, in this embodiment, two ratchet rings 38 are rotatably arranged side by side in the driven ring 35, and a plurality of bevel gears 3 mesh with the bevel gears 38a of the two ratchet rings 38, respectively.
9 is pivotally supported on the driven ring 35 via a shaft 40, and the claws 47 of the adjacent accelerators 49 are arranged alternately on the left and right, so that they are in alternate elastic contact with the left and right ratchets 38b. When driving the driven ring 35, the two left and right pawls 47 simultaneously engage with the ratchet 38b, and the driven ring 3
5 will be driven. In other words, since this drive uses a differential similar to the drive of the drive wheels through a differential gear of an automobile, the driving ring 35 is driven at the average speed of the left and right pawls 47. . This differential gear mechanism therefore further reduces transmission force pulsations.

Next, the operation of the reverse input permitting device will be explained. The above explanation is an explanation of the operation when the bicycle is running (forward rotation), but if a bicycle equipped with this continuously variable transmission stops in the middle of a hill, for example, and moves backwards due to the action of gravity, Since the chain 8 moves in the direction of arrow R in FIG. 4, the driving ring 35 is moved through the sprocket 36 as shown in FIG.
A reverse input is applied that rotates in the direction of arrow S.

When the driving ring 35 rotates in the direction of arrow S,
The accelerator 49 including the ratchet 38b and pawl 47 rotates in the direction of the arrow S, and as a result, the bases 18 and 19 also rotate in the direction of the arrow S via the pivot shaft 43 of the accelerator 49, as shown in FIG. try to rotate.

In this case, in this embodiment, the bases 18, 19
are rotatably supported by bearings 12 and 20, respectively, and a one-way clutch 21 is provided between the fixed member differential frame 24 and the base B19 to allow rotation in the direction of arrow S. Reverse input in the direction of arrow S can be easily tolerated by the above-described mechanism.

Note that if the crank arm 6 and crankshaft 5 are stopped at the time of this reverse input, the carrier 9 is also stopped, so the base plate A18 is stopped as shown in FIG.
When rotates in the direction of arrow S, the planetary gear 11 rotates in the direction of arrow K, and the sun gear 13 rotates in the direction of arrow L.

Therefore, the accelerator 49 moves differentially as described above, but in this case, the bases 18 and 19 supporting the accelerator 49 via the pivot shaft 43 rotate in the direction of the arrow S in FIG. I'll run away, so there won't be any problems.

(Effects of the Invention) Since the continuously variable transmission of the present invention is constructed as described above, chain transmission is possible by integrally forming the sprocket with the output driving ring. Therefore, it is possible to eliminate the transmission loss caused by slip in the conventional belt transmission type transmission.

Further, the continuously variable transmission of the present invention has the advantage that, due to its structure, it can comfortably and reliably perform a gear shift operation even when the vehicle is stopped or when the vehicle is running, and the gear shift operation is extremely easy.

Furthermore, when compared with a conventional variable transmission device using a planetary gear, the continuously variable transmission device of the present invention changes speed simply by an accelerator that performs an oscillating motion.
Since this accelerator can be provided in a much larger number (approximately twice as many) as compared to the conventional planetary gear, it is possible to achieve the effect that the pulsation of the transmission force can be reduced accordingly.

In addition, the accelerator's rocking motion range, which determines the magnitude of the transmission speed, is structurally limited to a rocking angle of the accelerator from 0° to approximately
Since it is possible to set it arbitrarily up to 100°,
An excellent effect can be obtained in that the range of variation (variation magnification) of the speed ratio can be significantly expanded compared to a conventional system using a planetary gear.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of the device of the present invention, and FIG.
AA sectional view, FIGS. 3 and 4 are exploded perspective views of the device of the present invention, FIG. 5 is a BB sectional view of FIG. 1, and FIG. 6 is a C-C sectional view of FIG. 1. 7 and 8 are partially cutaway front views of the eccentric cam section, and FIGS. 9 and 10 are explanatory diagrams of the operation of the accelerator. 4... Hangaratsug, 5... Crankshaft (drive shaft), 6... Crank arm, 8... Chain, 9
...Carrier, 11...Planetary gear, 12...Bearing, 13...Sun gear, 15...Inner eccentric cam, 16...Outer eccentric cam, 17...Bearing, 18...Base A, 19...Base B, 20...
Bearing, 21...One-way clutch, 22...
Differential gear A, 23...Differential gear B, 24...Differential frame, 25...Internal gear, 26...Wire reel, 27...Plate, 29...Inner wire, 30...Outer wire, 32, 34... Planet gear, 35... Output driving ring, 36... Sprocket, 37... Bearing, 38... Ratchet ring, 39... Bevel gear, 42... Plate bell crank, 43... Pivotal Support shaft, 44...Roller, 4
7...Claw, 48...Coil spring, 49...Accelerator, 50...Coil spring, 51...Color.

Claims (1)

[Claims] 1. A disc-shaped carrier with a plurality of planetary gears is fixed to the end of the crankshaft of the bicycle, and a sun gear that meshes with the planetary gears is rotatably provided in the middle of the crankshaft. An eccentric cam whose eccentricity can be freely adjusted with respect to the crankshaft is rotatably provided in the cylindrical portion, and both sides of the eccentric cam are surrounded by two bases that are locked to a fixed member during normal rotation,
An internal gear carved on the inner periphery of the outer base is meshed with the planetary gear, and between the outer peripheries of the two bases,
An output driven ring with a ratchet on the inner circumferential surface is rotatably provided, one end of the bell crank is pivoted between the two bases, and a corner of the bell crank is attached to the outer circumference of the eccentric cam. A plurality of accelerators are disposed between the eccentric cam and the driven ring, the claws of which are pivoted to the other end of the bell crank are brought into elastic contact with the ratchets of the driven ring. Continuously variable transmission for bicycles.