JPH025628B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is mainly suitable for bicycle transmissions, which are capable of steplessly variable speed transmission by means of a pawl that engages with an internal ratchet. This relates to continuously variable transmissions.

(Prior art) As a conventional device of this type, for example,
There is one disclosed in Publication No. 1722.

(Problems to be Solved by the Invention) However, since the above-mentioned conventional device has a single-row pawl feeding mechanism, there is a limit to the number of pawls that can be attached, and as a result, pulsation is not sufficiently eliminated. There was a problem.

Furthermore, when the conventional device sequentially relays the load applied to each pawl in the drive range during eccentricity, the speed difference between the drive ratchet and the driven pawl to which the next load is applied makes it difficult for the drive ratchet to engage next. There was a problem in that a gap was created between the tips of the teeth of the driven pawl and a shock occurred when the driven pawl was replaced.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to significantly reduce pulsation and shock during speed-up driving of this type of continuously variable transmission.

(Means for Solving the Problems) In order to solve the above problems, in the present invention, multiple rows of internally toothed ratchet rings are arranged in parallel on the inner periphery of the rotating member on the input side via one-way clutches. ,
The bases of the multiple rows of pawls that mesh with the ratchets of this internal tooth ratchet ring are alternately arranged and pivoted on carriers that are rotatably provided on eccentric cams that can freely adjust the amount of eccentricity with respect to the central axis. A plurality of rows of internally toothed ratchet rings are arranged in parallel on the inner periphery of the ring portion formed integrally with the internal toothed ratchet ring via a one-way clutch, and the bases of the multiple rows of pawls that mesh with the ratchets of this internally toothed ratchet ring are connected to the output side. A continuously variable transmission is constructed by being pivotally supported by the rotating member.

(Function) As described above, in the present invention, since the ratchet rings and pawls are provided in multiple rows,
The number of nails that can be attached can be greatly increased compared to a single row type. Therefore, the pulsation of the transmission force can be significantly reduced.

Further, the plurality of rows of internal toothed ratchet rings are each provided on the driving side member via a one-way clutch so as to be rotatable in only one direction, and the claws of the plurality of rows are arranged so as to alternately mesh with the ratchets of the internal toothed ratchet rings. Therefore, it is possible to prevent the shock from occurring when the driven claws are replaced.

(Example) Hereinafter, an example in which the present invention is applied to a continuously variable transmission for a bicycle will be described with reference to the drawings.

In the figure, 1 is a chain stay of a bicycle frame, 2 is a rear wheel hub shaft fixed to the chain stay 1 with a lock nut 3, 4 is a rear wheel hub rotatably fitted through bearings 5 and 6, and 7 is a spoke.

In this embodiment, an inner eccentric cam 8 is screwed and fixed to the threaded portion 2a of the rear wheel hub axle 2 on the outer side of the bearing 5, and an outer The eccentric cam 10 is rotatably fitted. 11 is an operating wire wound around this wire reel 9, 11a (see Fig. 2)
is the wire end.

Also, a small diameter cylindrical portion 12a and a large diameter cylindrical portion 12b.
The small diameter cylindrical part 12a of this carrier 12 is fitted to the outer periphery of the outer eccentric cam 10 via the bearing 13, and the large diameter cylindrical part 12b is connected to the rear wheel hub 4. It is located in a hollow cylindrical case 4a that is integrally formed with.

Also, 14 is a dish-shaped case, and this case 14
is fixed to the rear wheel hub axle 2 by an inner eccentric cam 8 and a lock nut 3. 15 is a sprocket for the rear wheel, and 15a is a cylindrical portion formed integrally with this sprocket 15.
5 is rotatably provided between the case 14 and the rear wheel hub 4 via bearings 16 and 17.
18 is a chain.

Further, on the inner circumferential surface of the cylindrical portion 15a of the sprocket 15, there are a plurality of rows (two rows in this embodiment, but three or more rows can also be provided) via the one-way clutch 19.
ratchet rings 20, 21 are arranged in parallel, and ratchets 20a, 21a are provided on the inner circumferential surface of each of these ratchet rings 20, 21, respectively, and each row has a plurality of double rows that mesh with the ratchets 20a, 21a, respectively. (5 in this example) claws 2
The bases of the carriers 2 and 23 are arranged alternately on the left and right sides of the outer circumference of the small-diameter cylindrical portion 12a of the carrier 12 via pins 24, and are pivotally supported. Note that 19a is a ball forming the one-way clutch 19, and 19b is its extrusion spring. The one-way clutch 19 can also be of other types, for example using a ratchet and pawl. Further, reference numeral 25 denotes a spring for always pressing the tips of the claws 22, 23 against the ratchets 20a, 21a.

Furthermore, a plurality of rows (two rows in this embodiment) of ratchet rings 2 are connected to the inner peripheral surface of the large diameter cylindrical portion 12b of the carrier 12 via a one-way clutch 19 similar to that described above.
6 and 27 are installed in parallel, and each of these ratchet rings 2
Ratchets 26a, 26a and 27 are provided on the inner peripheral surfaces of
27a and ratchets 26a, 27
The bases of the double-row pawls 28 and 29, each row having a plurality of pawls (five in this example), which mesh with the a,
The rear wheel hub 4 is pivotally supported by being arranged alternately on the left and right sides via pins 30 on the outer circumference of the boss portion 4b inside the case 4a of the rear wheel hub 4. Incidentally, reference numeral 31 denotes a spring for keeping the tips of the claws 28, 29 in pressure contact with the ratchets 26a, 27a.

Next, the operation of the apparatus of the present invention constructed as described above will be explained. First, to explain the transmission sequence in the embodiment shown in FIGS. 1 to 3, the crank gear rotates via a crank pedal (not shown), and the rotation is transmitted to the sprocket 15 by the chain 18. The rotation of the sprocket 15 is transmitted to the ratchet rings 20, 21 via the one-way clutch 19, and the pawls 22, 2 are further transmitted from the ratchets 20a, 21a to the ratchet rings 20, 21.
3. It is transmitted to the carrier 12 via the pin 24. When the carrier 12 rotates, the ratchet rings 26, 27 rotate via the one-way clutch 19, and as a result rotation is transmitted to the rear wheel hub 4 via the pawls 28, 29 and pin 30.

In other words, in this device, the claws 22 and 23
The power is transmitted through two sets of transmissions: a first-stage transmission and a second-stage transmission using pawls 28 and 29.

1 to 3 show the case where the outer eccentric cam 10 is in the maximum eccentric state, and the operating wire 11
When the outer eccentric cam 10 is rotated by 180 degrees, the outer peripheral surface of the outer eccentric cam 10 becomes concentric with the rear wheel hub shaft 2, as shown in FIG. It should be noted that since FIG. 4 and subsequent figures are action explanatory diagrams, the number of claws is also reduced. Furthermore, since the configurations of the two sets of transmissions are the same, the same drawings will be described. When the outer eccentric cam 10 becomes concentric as described above, the drive rotating body 15
a, 12b, and each ratchet ring 20, 2
1, 26, and 27 are also concentric with the rear wheel hub axle 2, so when the drive rotor rotates in the direction of arrow C in FIG. Because it rotates,
The gear ratio in this case is 1:1.

Further, when the outer eccentric cam 10 is rotated 180 degrees from the state shown in FIG. 4 by operating the operating wire 11 to reach the maximum eccentric state as shown in FIG. Rotation is performed via a one-way clutch 19, such as ratchet rings 20, 21,
26, 27, ratchet rings 20, 2
6 is connected to the driven rotating body 12 via the pawls 22 and 28 in row a.
Transmit rotation to a, 4, ratchet rings 21, 2
7 is the driven rotating body 12 via the pawls 23 and 29 of the b row.
Transmit rotation to a and 4.

If the outer eccentric cam 10 is eccentric, the claw a ₁ within the drive range E shown in FIG.
Since the speed increase rate is maximum, the driven rotor 12
a, 4 are rotated at increased speed by this pawl _a1 , and the other pawls are ratchet rings 20, 21, 26, 27.
Each ratchet 20a, 21a, 26a, 27a
This results in a sliding rotation in the direction of arrow F.

Then, as the pawl a ₁ moves out of the drive range E, the pawl b ₁
When it enters the drive range E, it is now driven at an increased speed via pawl b ₁ , and the transmission pawls are sequentially changed to pawls a ₂ , b ₂ , a ₃ , and b ₃ .

In this case, the gear ratio (speed increasing ratio) is the rear wheel hub axle 2.
The angle θ ₁ which is the special area of the claw with the center 0 ₁ as the base point
is the ratio of the angle θ ₂ which is the drive range of the pawl with the center 0 ₃ of the outer eccentric cam 10 as the starting point. The maximum speed increasing ratio of this embodiment shown in Figures 1 to 3 is approximately
1.45 and the second row is about 1.48, so the total is about 2.15.

Note that the speed increase rate transmitted through the claws in the drive range E is not uniform over the entire range of the drive range E, and this appears as pulsations in the transmission force.
The smaller this drive range E is, the smaller the pulsation becomes. In other words, the greater the number of pawls, the smaller the pulsation can be. However, in the present invention, the ratchet ring and pawls are arranged in multiple rows, so the number of pawls installed can be reduced compared to the conventional single row. can be more than doubled. Therefore, according to the present invention, pulsations occurring in the transmission system can be significantly reduced.

In addition, with conventional single-row devices, when the pawls in the drive range change, if there is a gap between the tip of the pawl that is being replaced and the tooth surface of the ratchet, this gap can cause a shock. The dot was hot.

In contrast, in the present invention, a plurality of rows of internally toothed ratchet rings are provided on the drive side member via one-way clutches so as to be rotatable in only one direction, and the pawls in the plurality of rows are alternately connected to the internally toothed ratchet rings. Since it is arranged so as to mesh with the ratchet of the ring, it is possible to prevent the occurrence of a shock when the driven pawl is changed as described above.

In other words, the pawls _a1 in the a row in the drive range E in FIG.
The driving force from a, 12b is transferred to the driven rotating bodies 12a, 4.
tell.

In this case, the other pawls b ₁ , a ₂ , b ₂ , a ₃ , and b ₃ are all rotated in the direction of arrow F relative to the ratchet because their toe speeds are faster than the rotational speed of the ratchet. Since no load is applied to the pawl _b1 whose toe speed is closest to the ratchet speed, the ratchet ring in the row B is rotated in the clockwise direction in which the one-way clutch 19 does not work, rather than the ratchet rings 20 and 26 in the row A. 21 and 27 can be rotated quickly by frictional driving by the pawls in the b row.

In other words, the power to rotate the ratchet rings 21, 27 in row b faster than row a is due to the power generated by the pawls in row b.
This is caused by the drag caused by the contact friction of the fast toe speeds of b ₂ and b ₃ , and the slowest speed pawl b ₁ in row b is moved forward before reaching the drive range E, that is, in front of the relay receiving angle. At the ratchets 21a and 27 of row b
Since it enters the drive range E in a state where it is tightly meshed with a, the rotational force of the drive rotors 15a and 12b is transferred to the two rows of pawls b ₁
is received without a transfer shock, and smooth rotation can be obtained by sequentially relaying the a and b rows alternately.

(Effects of the Invention) As described above, in the present invention, since the ratchet rings and pawls are provided in multiple rows,
The number of nails that can be attached can be significantly increased compared to a single row type. Therefore, it is possible to obtain the effect that the pulsation of the transmission force can be significantly reduced.

Further, a plurality of rows of internal toothed ratchet rings are provided on the drive side member via one-way clutches so as to be rotatable in only one direction, and the pawls of the plurality of rows are alternately engaged with the ratchets of the internal toothed ratchet rings. Since the driven pawls are arranged in the same direction, it is possible to prevent the occurrence of shock when the driven pawls are replaced. Therefore, according to the present invention, an excellent effect can be obtained in that overall smooth rotation with less pulsation and shock can be obtained. It will be done.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional plan view of the device of the present invention, Fig. 2 is a sectional view taken along line A-A in Fig. 1, Fig. 3 is a sectional view taken along line B-B in Fig. 1, and Figs. 4 and 5 are explanations of the operation. It is a diagram. 1... Chain stay, 2... Rear wheel hub axle, 3... Lock nut, 4... Rear wheel hub, 8... Inner eccentric cam, 1
0...Outside eccentric cam, 11...Operation wire, 12...Carrier, 15...Sprocket, 18...Chain, 1
9... Directional clutch, 20, 21... Ratchet ring, 22, 23... Pawl, 26, 27... Ratchet ring, 28, 29... Pawl.

Claims (1)

[Claims] 1. A plurality of rows of internal tooth ratchet rings are arranged in parallel on the inner periphery of the rotating member on the input side via a one-way clutch,
The bases of the multiple rows of pawls that mesh with the ratchets of this internal tooth ratchet ring are alternately arranged and pivoted on carriers that are rotatably provided on eccentric cams that can freely adjust the amount of eccentricity with respect to the central axis. A plurality of rows of internally toothed ratchet rings are arranged in parallel on the inner periphery of the ring portion formed integrally with the internal toothed ratchet ring via a one-way clutch, and the bases of the multiple rows of pawls that mesh with the ratchets of this internally toothed ratchet ring are connected to the output side. A continuously variable transmission that is pivotally supported on a rotating member.