JPS5938465B2 - Gear ratio switching device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gear ratio switching device, and a first rotation that directly transmits a first rotation to an output shaft only when a human power shaft connected to a drive source such as a motor rotates in the positive direction. It is composed of a transmission means and a second rotation transmission means that directly transmits the second rotation to the output shaft only when rotating in the opposite direction, and slides and rotates when rotating in the forward direction and does not transmit the rotation to the output shaft. Accordingly, it is an object of the present invention to provide a speed change switching device that can operate smoothly when changing a speed ratio and shorten the switching time.

As shown in FIG. 1, the conventional gear ratio switching device rotates a connecting rod 3, which connects the shafts of gears 1 and 2 with different gear ratios, around a fulcrum 4, thereby switching the gears 1 and 2, respectively. The clockwise and counterclockwise rotations of the gear 5 are transmitted to the gears 1 and 2, respectively, by switching and meshing with the gear 5 that is interlocked with the motor. - A configuration in which rotations with different rotational directions and gear ratios are extracted from the gears 1 and 2. It was said that

Conversely, by switching gears 1 and 2 that are interlocked with the motor and meshing them with gear 5, the clockwise and counterclockwise rotations of gears 1 and 2 are transmitted to gear 5. It was configured to take out rotations with different speed ratios.

However, in this conventional gear ratio switching device, it takes a long time to rotate the connecting rod 3 and switch gears 1 and 2, and if this switching is done instantaneously, a large load is placed on the motor. There was a drawback.

Further, when the gear 1 or the gear 27i is meshed with the gear 5, the teeth 8 of the gears abut each other, making it impossible to perform a smooth switching operation.

The present invention eliminates the above-mentioned drawbacks, and the gist thereof is to include a human-powered shaft that supplies rotation of the drive source in the forward and reverse directions;
It consists of an output shaft that outputs rotational output in the forward and reverse directions according to the rotation of the human power shaft, a transmission mechanism that changes the rotation speed of the human power shaft, and one one-way clutch. a first rotation transmission means that directly transmits the first rotation to the output shaft with a gear ratio of 1; a transmission mechanism for changing the rotation speed of the human-powered shaft; When rotating, a second rotation in the opposite direction to the first rotation is directly transmitted to the output shaft with a second gear ratio, and when rotating in the forward direction, the second rotation is slidably rotated between the output shaft and the output shaft. The present invention is characterized in that it includes a second rotation transmission means that does not directly transmit the rotation from the first transmission rotation means to the output shaft.

An embodiment of the present invention will be described below with reference to FIGS. 2A and 2B.

FIGS. 2A and 2B are a plan view and a front view taken along line B--B in FIG. 2A, respectively, of an embodiment of the gear ratio switching device according to the present invention.

In each figure, 6 is a gear whose rotating shaft 7 is fixed to the rotating shaft of a motor 8, and is rotated by the motor 8.

A gear 9 has, for example, the same number of teeth as the gear 6, and meshes with the gear 6.

Reference numeral 10 denotes a coil spring, one end 10a of which is press-fitted into a predetermined position on the gear 9, and is wound counterclockwise around a pipe 11 that is in contact with the gear 9, as is clear from Figure A. The other end 10b is a free end.

Note that the inner diameter of the coil spring 10 when not wound around the pipe 11 is set smaller than the diameter of the pipe 11, and the coil spring 10 is in pressure contact with the pipe 11.

A gear 12 has the same number of teeth as the gear 9, and its rotating shaft 13 is supported by a frame 14 through the gear 9. The pipe 11 is mounted on the rotating shaft 13. Fixed.

A spacer 15 is separately interposed between the gear 9 and the gear 12, and is loosely fitted onto the shaft 13.

A gear 16 has, for example, 02 times as many teeth as the gear 12, meshes with the gear 12, and has a rotating shaft 17 supported by the frame 14.

A gear 18 has, for example, 1/2 the number of teeth of the gear 6, and meshes with the gear 16, and its rotating shaft 19 is supported on the frame 14.

Reference numeral 20 denotes a receiving plate, which is fixed to the rotating shaft 19 and is attached to the rotating shaft 1.
Rotates integrally with 9.

21 is a collar, which includes a rotating shaft 19, a gear 18, and a receiving plate 20c.
These are fixed and rotate together with them.

Reference numeral 22 denotes a gear, which has, for example, 1.5 times the number of teeth as the gear 6, and is meshed with the gear 6.A collar 22 is provided with a collar, which is rotatably provided separately from the collar. It's fitted.

23 is a disc spring, which loosely fits into the collar 21 and is attached to the gear 22.
and the gear 18.

Note that the disc spring 23 is pressed against the gear 18 by its biasing force.

The relationship between the slip torque τ1 between the coil spring 10 and the pipe 11, the slip torque τ2 between the gear 22, the disc spring 23, and the gear 18, and the tightening torque τ3 between the coil spring 10 and the pipe 11 is as follows. τ1(τ2
(Set to τ3.

Next, the operation of the above-mentioned component device will be explained.

2A, Blcg, when the motor 8 rotates counterclockwise at a predetermined speed, the gear 6 rotates integrally with the rotating shaft 7 in the direction of arrow a1, and the gear 9 rotates in the direction of arrow a2.

Here, since the coil spring 10 is wound around the pipe 11 in a counterclockwise direction (in the direction opposite to the arrow a2 direction),
It is tightened as the gear 9 rotates in the direction of arrow a2.

Therefore, the pipe 11 is connected to the gear 9 and the coil spring 1.
The gear 12, which is fixed to the pipe 11, also rotates in the direction of arrow a2;
reactor.

Therefore, the gear 16 rotates in the direction of arrow a3 at a speed of 1/2 of the rotational speed of the motor 8, and its rotating shaft 17 similarly rotates in the direction of arrow a3, so that the speed of the motor 8 is 1/2 of the rotational speed of the motor 8.
The counterclockwise rotation decelerated to is extracted.

Further, the rotation of the gear 16 is transmitted to the gear 18, and the rotation of the gear 16 is transmitted to the gear 18.
rotates in the direction of arrow a5.

On the other hand, the gear 60 rotation is transmitted to the gear 22, and the gear 22 rotates in the direction of arrow a4.

At this time, since the rotational torque of gear 18 is larger than the rotational torque of gear 220, disc spring 23 slides and rotates in the direction of arrow a4 (a5) while slipping between gear 18 and gear 18.

Therefore, the gear 22 and the gear 18 do not rotate together,
These rotate separately according to the rotational torque of gear 6 and gear 16, respectively.

Next, when the motor 8 rotates clockwise at the same predetermined speed as in the above case, the gear 6 rotates in the direction of the arrow b1,
The gear 9 rotates in the direction of arrow b2.

Here, the coil spring 10 is loosened as the gear 9 rotates, contrary to the above case.

Therefore, even if gear 9 rotates, coil spring 1
Since slip occurs due to ε between 0 and pipe 11,
The pipe 11 and the gear 12 do not rotate due to the rotational torque of the gear 9.

Therefore, rotation is not transmitted to the gear 16 from the gear 12.

On the other hand, the rotation of gear 6 is transmitted to gear 22, and gear 22 rotates in the direction of arrow b4 at a speed that is 2/3 of the rotation speed of gear 6.

At this time, since the rotational torque of the gear 16 is not transmitted to the gear 18, the disc spring 23 does not slip, and the disc spring 23
rotates integrally with the gear 22 in the direction of arrow b4.

Therefore, the gear 18 rotates integrally with the gear 22 and the disc spring 23 in the direction of arrow b5.

Therefore, the gear 16 rotates in the direction of arrow b3 in accordance with the rotational torque of the gear 18, and clockwise rotation that is reduced to 1/6 of the rotational speed of the motor 8 is extracted from the rotating shaft 17.

The gear 12 rotates by 160 rotations, but at this time a slip occurs between the coil spring 10 and the pipe 11.

The reason why disc springs are not used for gears 22 and 18 and gears 9 and 12 is that if disc springs that satisfy the relationship τ2 (τ3) are used for gears 9 and 12, when the motor 8 rotates counterclockwise, the rotation Output can be normally taken out to the shaft 17, but when the motor 8 rotates clockwise, the disc springs of the gears 9 and 12 do not slip, and the disc spring 23 slips again, so there is no output on the rotating shaft 17 regardless of the rotation direction. This is because only a constant number of rotations can be obtained at all times.

Also, the reason why coil springs are not used for gear 22.18 and gears 9 and 12 is that if a coil spring is used that is wound clockwise in pressure contact with gear 22.18, it will work normally when the motor 8 rotates clockwise. However, when the motor 8 rotates counterclockwise, the number of rotations of the gear 18, that is, the number of rotations of the rotating shaft 19, rotates at twice the number of rotations of the motor 8, and the number of rotations of the gear 22 is twice the number of rotations of the motor 8. Since the rotational speed of the rotating shaft 190 is smaller than the force of loosening the coil spring by the gear 22, Even though the gear 22 is rotating in the direction of arrow A4 (the direction in which the coil spring is loosened), the rotation shaft 19 tightens the coil spring, and as a result, the rotation torque of the gear 22 and the rotation torque of the gear 18 are different. This is because the gear mechanism will be destroyed.

Also, gear 9.12, coil spring 10, rotation shaft 1
The third mechanism is not limited to the above embodiment as long as it is a one-way clutch mechanism that transmits rotational torque in only one direction, and a mechanism such as a ratchet may be used.

Similarly, the mechanisms such as the gear 22° 18, the disc spring 23, and the rotating shaft 19 are not limited to the above embodiments as long as they are friction clutch mechanisms that transmit rotational torque in both directions, such as a fluid clutch or an electromagnetic clutch. A mechanism such as this may also be used.

Further, in the eighth embodiment, the driving output is taken out from the rotating shaft 17, but the driving output may be taken out from the rotating shaft 19.

Furthermore, in the above embodiment 8, the reduction ratio is switched, but it is also possible to supply the driving power to the rotating shaft 17 or 19 and take out the driving output from the rotating shaft 7. In this case, It can be used as a speed increasing ratio switching device.

As described above, according to the gear ratio switching device of the present invention, each means always operates in conjunction with the input shaft, so the time required to switch from forward rotation to reverse rotation or vice versa is reduced. It can be shortened compared to conventional devices, and since the teeth of the gears do not collide with each other during switching as in conventional devices, the switching operation can be performed smoothly. Therefore, even if the switching operation is instantaneous, It has the advantage of being able to completely reduce the load on the motor compared to the conventional example.

[Brief explanation of drawings]

FIG. 1 is a schematic front view of an example of a conventional speed ratio switching device, and FIGS. 2A and 2B are plan views of an embodiment of the speed ratio switching device according to the present invention, and the line BB in FIG. It is a front view seen from the side. 6.9, 12, 16, 18.22...Gear, 7
゜13.17,19...One rotation axis, 8...
・Motor, 10... Coil spring, 11.
...Pipe, 23... Disc spring.

Claims (1)

[Claims] 1. A human-powered shaft that supplies the rotation of the drive source in the forward and reverse directions, an output shaft that takes out the rotational output in the forward and reverse directions according to the rotation of the input shaft, and a transmission mechanism that changes the rotation speed of the human-powered shaft. a first rotation transmission means comprising one one-way clutch and directly transmitting a first rotation to the output shaft with a first gear ratio only when the human power shaft rotates in the positive direction; and a first rotation transmission means that changes the rotation speed of the human power shaft. It consists of a transmission mechanism and one friction clutch, and when the input shaft rotates in the opposite direction, it directly transmits a second rotation in the opposite direction to the first rotation to the output shaft with a second transmission ratio, and in the forward direction. 1. A speed ratio switching device characterized by comprising a second rotation transmission means that slides and rotates between the output shaft and the output shaft when the rotation of the first transmission rotation means is performed, and does not directly transmit the rotation from the first transmission rotation means to the output shaft.