JPH0558378A - Gear shifting device for bicycle - Google Patents

Abstract

PURPOSE:To mount a gear shifting device for a bicycle to a general bicycle and to reduce the cost and the weight of the device. CONSTITUTION:First and second follower rotary bodies 17 and 19 are geared with a rotary body 8 through first and second one-way clutches, and a plurality of sets of planetary gears 24 and 25 are disposed between the second follower rotary body 19 and a chain sprocket 21 to which the second follower rotary body is fixed. An internal gear 28 of the follower rotary body 17 is geared with the planetary gear 24, and a one-way clutch body of a clutch unit 33 is engaged with solar gears 29 and 30. The follower rotary body 19 is released from gearing through first low speed operation and the gear 30 is released from engagement through second low speed operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle transmission, and more particularly to a bicycle transmission having a planetary gear mechanism.

[0002]

2. Description of the Related Art A conventional transmission of this type having a planetary gear mechanism is disclosed in Japanese Utility Model Publication No. 28-19. Since this transmission has a structure in which the claw 13 is locked to the protrusion on the side surface of the sun gear, it is necessary to reliably lock and unlock the claw 13, which is extremely difficult to put into practical use. A transmission of this type is disclosed in Japanese Patent Laid-Open No. 62-99293. In this transmission, a carrier 11 is fixed to a crank arm 8, planetary gears 16 to 18 are attached to the carrier 11,
A plurality of internal gears 20 and the like provided in the conventional rotating body 24 are meshed with the planetary gear 16 and the like, and a sprocket 23 is provided in the driven rotating body 24.

[0003]

[Problems to be Solved by the Invention] However, JP-A-62-992
The transmission disclosed in Japanese Patent No. 93 has a structure in which a crank arm 8 and a carrier 11 having a planetary gear are integrated with each other, and have a structure for shifting in a speed increasing direction. For this reason, when this device is attached to a bicycle that does not have a transmission, it is difficult to obtain a suitable speed ratio because the sprocket has a large diameter, and it is more common to attach the transmission of the publication to a general bicycle. It is structurally impossible because the right cup provided with the left-hand screw is applied with a rotational force in a loosening direction at high speed. Further, when the driven rotary body 24 is provided with a plurality of internal gears 20 and the like, the driven rotary body 24 becomes expensive and heavy. The present invention has been made to solve such a point,
It is an object of the present invention to provide an inexpensive and lightweight transmission that can be installed even on a general bicycle.

[0004]

In the bicycle transmission of the present invention, the first and second one-way clutches are provided to the rotating body which is fixed to the crank arm and transmits the rotational force thereof. 2 driven rotors are meshed with each other, and a planetary gear group consisting of a plurality of planetary gears coaxially fixed to each other is arranged between the second driven rotor and the fixed chain sprocket. The planetary gears with the smallest number of teeth in each set are meshed with the internal gears provided in the first driven rotor, and the one-way clutches of the clutch unit are combined with the plurality of sun gears meshed with the planetary gears in each set. The second one-way clutch is disengaged by engaging the inner peripheral side with the clutch releasing mechanism to disengage the second one-way clutch by the first low speed operation. The low speed operation of each of the clutch units It is characterized in that to idle sequentially sun gear by disengaging the direction clutch.

[0005]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a sectional view of a bicycle transmission according to the present invention. In FIG. 1, reference numeral 1 denotes a crank arm. The boss portion of the crank arm 1 is fixedly fitted to the end portion of the crank shaft 2, and the cap 4 is screwed in while covering the retaining member 3 screwed to the end of the crank shaft 2. .. A hanger pipe 5 is arranged on the crankshaft 2, and a right cup 6 is provided at one end of the hanger pipe 5.
Is screwed in. The right cup 6 is supported on the crankshaft 2 via a sphere 7.

A rotating body 8 is fitted and fixed to the boss portion of the crank arm 1 through a disc-shaped cover member 9.
2A and 2B are a front view and a side view of the rotating body 8. The rotating body 8 has annular portions 10 and 11, and the first claw members 12 and 1 are provided in the voids 10 a and 10 a of the one annular portion 10.
Two are arranged. These claw members 12 are rotatably mounted on a support shaft 13 and are biased via a claw spring 14 so as to project from the peripheral surface of the annular portion 10. The second claw members 15, 15 are provided in the gaps 11a, 11a of the other annular portion 11.
Are arranged. These claw members 15 are likewise supported by the support shaft 1.
6 is rotatably attached to the annular portion 1 via a pawl spring 14.
It is biased so as to project from the peripheral surface of No. 1. Claw member 1
An inclined surface 15a is formed on the base side of the clutch plate 5, as shown in FIGS.
Pressed at 6. A first driven rotating body 17 composed of a ratchet wheel is arranged around the annular portion 10 of the rotating body 8. As shown in FIGS. 1 and 3, the driven rotating body 17 includes an annular portion 1
A ratchet 18 is formed on the inner peripheral portion along the peripheral surface of 0. The ratchet 18 has the above-described first claw member 1
The tips of 2 and 12 project and are locked via the claw springs 14. The first claw members 12, 12 and the ratchet 18
Constitutes a first one-way clutch.

A second driven rotor 19 composed of a ratchet wheel is arranged around the annular portion 11 of the rotor 8. As shown in FIGS. 1 and 4, the driven rotating body 19 has a ratchet 20 formed on the inner peripheral portion along the peripheral surface of the annular portion 11.
The ratchet 20 includes the second claw members 15 and 1 described above.
The tip of 5 projects and is locked via the claw spring 14.
The second claw members 15 and 15 and the ratchet 20 are
Constitutes a one-way clutch.

The second driven rotary member 19 is fixed to a chain sprocket 21 as shown in FIGS. 1 and 5. That is, the second driven rotating body 19 has a plurality of holding bolts 2
2 and a nut 23 are coaxially fixed to the chain sprocket 21, and a spacer 27 is provided on the holding bolt 22.
Are spaced at regular intervals. Between the chain sprocket 21 and the second driven rotation point 19, as shown in FIGS. 1 and 5, four sets of planetary gear groups are arranged on the same circumference. Each set of planetary gear groups includes a pair of planetary gears 24,
25, the planetary gears 24, 25 have different numbers of teeth, and are coaxially and rotatably mounted on a support shaft 26. The surfaces of the planetary gears 24, 25 facing each other are fixed.

An internal gear 28 is formed on the inner peripheral surface of the first driven rotor 17 on the outer end side. The internal gear 28 is meshed with each planet gear 24 having a small number of teeth from the outside. As shown in FIGS. 6 and 7, each set of planetary gears 24 meshes with a large-diameter sun gear 29, and each set of other planetary gears 25 meshes with a small-diameter sun gear 30. These sun gears 29, 30 are shown in FIGS.
As shown in FIG. 7, ratchets 31 and 32 are formed on the inner peripheral surface, respectively, to engage with one-way clutches of a clutch unit 33 described later.

A clutch unit 33 is arranged on the crankshaft 2 as shown in FIG. FIG. 8 (A),
(B) and (C) are the front view, side view, and rear view of the clutch unit 33. The clutch unit 33 includes a main body 34 formed in a cylindrical shape, and side walls of the main body 34 are provided with substantially arcuate openings 35, 35 facing each other. Claw members 36 are arranged in these openings 35, and each claw member 36 is rotatably mounted on a support shaft 37 and a claw spring 38.
The tip is urged so as to protrude from the peripheral surface of the main body 34 via. Substantially semicircular recesses 39, 39 are formed on the peripheral surface on the back side of the main body 34. A locking member 40 having a substantially semi-circular shape is inserted into these recesses 39, and a holding spring 41 is inserted into a recess 40a (see FIG. 6) of each locking member 40, whereby the locking member 40 is inserted into the main body 34. It is attached in a protruding state on the peripheral surface of.

As shown in FIG. 6, the ratchet 31 of the large-diameter sun gear 29 is engaged with the engaging members 40, 40 of the clutch unit 33, and the ratchet 32 of the small-diameter sun gear 30 is shown in FIG. Further, as shown in FIG. 7, the claw members 36, 36 of the clutch unit 33 are locked. The clutch unit 33 is provided with a clutch release mechanism 42. This clutch release mechanism 42 is shown in FIG. 1, FIG. 8 and FIG.
As shown in FIG. 3, the clutch unit 33 has a cylindrical cam 43 arranged inside the main body 34. An opening cam portion 44 in which the base of the pawl member 36 is inserted into the cylindrical cam 43,
44 is provided, and an uneven cam portion 45 is formed on the rear end surface. As shown in FIG. 9, the cam portion 45 has
The cam portion 46a of the clutch plate 46 is engaged. This clutch plate 46, as shown in FIG.
A pair of support shafts 47, 4 protruding from the rear end surface of the main body 34
It is pierced and supported by 7 so as to be movable in the thickness direction.

The clutch release mechanism 42 is a cylindrical cam 4
3 has a speed change arm 51 formed integrally therewith. A connecting portion 52 is formed at the tip of the speed change arm 51, and one end of a speed change wire 53 is connected to the connecting portion 52, as shown in FIG. The other end of the speed change wire 53 is connected to an operation lever (not shown) attached to a handle or the like. The clutch plate 46 is a cam portion 46a.
Is engaged with the cam portion 45 of the cylindrical cam 43,
As shown in FIGS. 1 and 9, the second claw member 15 faces the inclined surface 15 a. The clutch plate 46 and the rotating body 8
As shown in FIG. 1, a coil spring 48 is disposed between the front surface of the main body 34 of the clutch unit 33 and the inner flange of the right cup 6 in the same manner as the other coil spring. 49 are arranged. Further, the main body 34 of the clutch unit 33 and the chain sprocket 21 are
A bearing 50 is disposed between the inner periphery of the bearing and the inner periphery of the bearing.

The first and second driven rotors 17 and 19 are provided.
1, etc. are covered with a cover 54, and the flange on the outer periphery of the cover 54 is fixed to the outer peripheral side of the chain sprocket 21 via bolts 55 and nuts 56.

Next, the operation of the bicycle transmission according to the present invention will be described. First, the speed change arm 5 of the clutch release mechanism 42
1 will be described when the vehicle is running normally with the vehicle 1 held in the state shown in FIG. That is, during normal traveling, the claw members 36, 36 and the locking members 40, 40 of the clutch unit 33 are locked to the ratchet 32 of the sun gear 30 and the ratchet 31 of the sun gear 29 as shown in FIGS. 7 and 6. is doing.
Further, as shown in FIGS. 3 and 4, the first claw members 12, 12 and the second claw members 15, 15 of the rotating body 8 have the ratchet 18 and the second driven body 17 of the first driven rotating body 17, respectively. Rotating body 1
It is locked to the ratchet 20 of 9.

Therefore, when the crank arm 1 is rotated,
The rotational force is transmitted to the chain sprocket 21 to which the rotary body 19 is directly fixed, via the rotary body 8, the ratchet 20, and the second driven rotary body 19. Therefore,
The crank arm 1 and the chain sprocket 21 rotate at the same speed. On the other hand, the sun gears 29, 30 are the planetary gears 24, 2 moving together with the chain sprocket 21.
5, the claw member 36 and the locking member 40 are rotated by the planetary gears in the non-locking direction, so that the planetary gear rotates (spins) together with the chain sprocket 21. Since the first driven rotating body 17 rotates slightly faster than the second driven rotating body 19, the first claw members 12, 12 are held in the ratchet 18 in the non-locking state.

Then, when the shift wire 53 shown in FIG. 10 is pulled, the shift arm 51 rotates clockwise as shown in FIG. 11, so that the cylindrical cam 43 of the clutch releasing mechanism 42 is rotated.
Rotates. When the cylindrical cam 43 rotates, the convex portion of the cam portion 45 presses the convex portion of the cam portion 46a of the clutch plate 46, as shown in FIG. Therefore, the clutch plate 46 moves in the thickness direction against the elastic force of the coil spring 48 (see FIG. 1), so that the inclined surface 15a of the second claw members 15 and 15 is pressed, and as shown in FIG. Then, the claw members 15 are rotated. As a result, the tips of the claw members 15 are disengaged from the ratchet 20 of the second driven rotary body 19, and the locking is released.

When the crank arm 1 is rotated in such a state, the first claw members 12 and 12 are locked to the ratchet 18 of the first driven rotor 17, so that the first driven rotor 17 is rotated. Rotational force is applied via the body 8. When the first driven rotating body 17 is rotated by this rotational force, the integrally formed internal gear 28 is rotated, and the planetary gears 24 having a small number of teeth in each set are rotated. These planetary gears 24
Is fixed to a large-diameter planetary gear 25 having a large number of teeth, these planetary gears 25 rotate at the same speed. When the large-diameter planetary gear rotates, a rotational force is applied to the meshing small-diameter sun gear 30. In this case, the small sun gear 30
Is applied to the pawl members 36, 36 by a rotational force in a direction in which the clutch unit 33 is engaged with the pawl members 36, 36, that is, a rotational force in a direction opposite to that of the crank arm 1. Therefore, the planetary gear 25 is centered on the small-diameter sun gear 30.
While rotating (24), it revolves in the same direction as the crank arm 1. As a result, the chain sprocket 21 rotates in the same direction at a lower speed than the crank arm 1 and is held at the first low speed.

On the other hand, since the large-diameter sun gear 29 rotates relatively in the opposite direction, the locking member 4 of the clutch unit 33 is rotated.
0 and 40 do not lock and continue reverse rotation. Next, further pulling the shift wire 53, as shown in FIG.
When 1 is rotated and the cylindrical cam 43 of the clutch release mechanism 42 is rotated, the opening cam portions 44, 44 are rotated and displaced, and the claw members 36, 36 of the clutch unit 33 are rotated. Therefore, as shown in FIG. 15, these claw members 3
6 and 36 are disengaged from the ratchet 32 of the small-diameter sun gear 30, and the locking is released. In this case, since the clutch plate 46 is still moving, the second pawl members 15 and 15 are disengaged from the ratchet 20 of the second driven rotor 19.

When the crank arm 1 is rotated in such a state, as described above, the first driven rotor 1 is rotated.
A rotating force is applied to 7 via the rotating body 8. Therefore, the planetary gears 24 having a small number of teeth in each set and the large-diameter planetary gears 25 integrally fixed to each other are rotated by the internal gear 28. In this case, since the small-diameter sun gear 30 has the claw members 36, 36 removed, it receives the rotational force of the large-diameter planetary gear 25 and rotates (spins) in the opposite direction.

On the other hand, the large-diameter sun gear 29 meshing with the small-diameter planetary gear 24 is engaged with the engaging members 40, 40 of the clutch unit 33 by applying a rotational force in the direction opposite to the crank arm 1. Therefore, the planetary gear 30 revolves in the same direction as the crank arm 1 while rotating about the large-diameter sun gear 29 as a center. Since a relatively low rotational force is applied to the large-diameter sun gear 29 by the planetary gear 30 having a small number of teeth, the revolution speed of these planetary gears 30 decreases, and therefore the chain sprocket 21 cranks at a lower speed. It rotates in the same direction as the arm 1 and is held at the second low speed.

As described above, when the rotational speed of the chain sprocket 21 is switched to the decelerating direction, even if the chain sprocket having a large diameter is attached to a bicycle which does not have a transmission, which is commercially available in advance, the present invention can be used. By applying the transmission as it is, the gear can be shifted at an optimum speed ratio. That is, when switching the chain sprocket to the speed increasing direction, it is difficult to obtain an optimum gear ratio with a large-diameter chain sprocket of a commercially available bicycle.

In the above embodiment, the sun gear 30 having a small diameter is used.
The number of teeth of the large diameter sun gear 29 is 64, the number of teeth of the small diameter planetary gear 24 is 16, the number of teeth of the large diameter planetary gear 25 is 32, and the number of teeth of the internal gear 28 is 96. When set to respectively, crank arm 1 and chain sprocket 2
Assuming that the speed ratio when 1 is directly connected is "1", it is "0.8" at the first low speed and "0.6" at the second low speed, and the optimum speed ratio is obtained. The one-way clutch in the above embodiment may have another structure.

[0023]

As described above, according to the present invention,
Despite its relatively simple and inexpensive configuration, it operates reliably,
Moreover, it is possible to provide a versatile bicycle transmission that can be applied to a commercially available bicycle as it is.

[Brief description of drawings]

FIG. 1 is a sectional view of a bicycle transmission according to the present invention.

2A and 2B are a front view and a plan view showing a rotating body of an apparatus according to the present invention together with a claw member.

FIG. 3 is a front view showing a first driven rotating body of the device according to the present invention together with a first one-way clutch.

FIG. 4 is a front view showing a second driven rotating body of the device according to the present invention together with a second one-way clutch.

FIG. 5 is a front view showing a second driven rotating body of the device according to the present invention together with a chain sprocket and a planetary gear.

FIG. 6 is a front view showing the relationship between the clutch unit and the sun gear of the device according to the present invention.

FIG. 7 is a front view showing the relationship between the clutch unit and another sun gear of the device according to the present invention.

8 (A), (B) and (C) are a front view, a side view and a rear view of a clutch unit of an apparatus according to the present invention.

FIG. 9 is a side view showing a clutch releasing mechanism of the device according to the present invention.

FIG. 10 is a partial cross-sectional view showing a cylindrical cam according to the present invention in relation to a claw member and a speed change wire.

FIG. 11 is a partial cross-sectional view showing a first low speed operation of the cylindrical cam according to the present invention.

FIG. 12 is a side view showing a first low speed operation of the clutch release mechanism of the present invention.

FIG. 13 is a front view illustrating unlocking of the claw member in the second driven rotary body of the present invention.

FIG. 14 is a partial cross-sectional view showing a second low speed operation of the cylindrical cam according to the present invention.

FIG. 15 is a front view illustrating unlocking of the sun gear of the clutch unit according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Crank arm 2 Crank shaft 8 Rotating body 12 First claw member 15 Second claw member 17 First driven rotating body 18,20 Ratchet 19 Second driven rotating body 21 Chain sprocket 24,25 Planetary gear 28 Internal teeth Gears 29, 30 Sun gear 31, 32 Ratchet 33 Clutch unit 36 Claw member 40 Locking member 42 Clutch release mechanism 43 Cylindrical cam 46 Clutch plate 51 Speed change arm

Claims (1)

[Claims] 1. A rotating body fixed to a crank arm for transmitting its rotational force, and a first meshing member meshing with the rotating body via a first one-way clutch.
A driven rotary body, a second driven rotary body that meshes with the rotary body via a second one-way clutch, and a chain sprocket in which the second driven rotary body is separated and coaxially fixed. A planetary gear group consisting of a plurality of sets of planetary gears arranged on the same circumference between the chain sprocket and the second driven rotating body, and coaxially arranged and fixed to each other A plurality of sun gears that are coaxially arranged and mesh with the planetary gears of the respective sets; and a plurality of sun gears that are provided on the inner peripheral side of the first driven rotor and that mesh with the planetary gears of the smallest number of teeth in the respective groups. An internal gear, a clutch unit arranged on the crankshaft for engaging a one-way clutch on the inner peripheral side of each sun gear, and a second low-speed operation for engaging the second one-way clutch. Release it, and operate it at the second or lower speed. And a clutch release mechanism for releasing each one-way clutch of the clutch unit.