Field of the invention

The present invention relates to an automatic speed shifting method and a device therefor, in which the rotary power is transmitted at the same revolution speed from one axis to another axis based on the principle of the gear pump, by utilizing an oil pressure and absorbing impacts. Further, a plurality of such rotary power transmitting devices are combined with one way clutch gears to connect the acceleration and deceleration rates suitably, thereby carrying out an automatic speed shifting.

Background of the invention

As the conventional automatic speed shifting devices for automobiles, there are many kinds including that in which a torque converter is combined with planetary gears. The conventional automatic speed shifting devices are complex in their constitutions and large in their bulks, with the result that they are inconvenient in handling, and the energy consumption is large.

Summary of the invention The present invention is intended to overcome the above described disadvantages of the conventional techniques.

Therefore it is the object of the present invention to provide an automatic speed shifting device in which an automatic valve is made to be capable of automatically adjusting the oil flow based on the principle of the gear pump and by utilizing an oil pressure, and this automatic valve is coupled with a one way clutch gear as

shown in Figure 5, oil being filled in the interior, so that the efficiency should be enhanced, and that the constitution should be simple, compared with the conventional devices.

Therefore, the device of the present invention can be conveniently applied to automobiles, auto cycles, marine vessels and the like.

Brief description of the drawings

The above object and other advantages of the present invention will become more apparent by describing in detail the preferred embodiment of the present invention with reference to the attached drawings in which:

Figure 1 is a plan view showing the device without attaching the valve;

Figure 2 is a plan view showing the device with the valve attached;

Figure 3 is a side view of the device of Figure 2;

Figure 4 is a detailed view of the valve of Figure 2; and

Figure 5 illustrates the automatic speed shifting device.

Description of the preferred embodiment If an input side central gear 1 is rotated slowly, a peripheral gear 2 which is disposed around revolves also slowly. Owing to the revolutions of the central gear 1 and the peripheral gear 2, there is produced an oil pressure. Under this condition, a valve 6 is open as shown in Figure 4 by the function of a spring 8, and therefore, an oil 5 flows toward an oil 4 in a natural manner.

Therefore, when a body 3 is stopped without revolutions, the peripheral gear 2 rotates on its own axis. When the revolution of

the central gear 1 is accelerated, the pressure of the oil 5 is increased, with the result that the body 3 is made to revolve.

Therefore, the peripheral gear 2 performs the rotational and orbital motions simultaneously. Under this condition, if the revolution of the central gear 1 is made faster, the revolution of the body 3 is also accelerated. Therefore, owing to the centrifugal force of the body 3, the piston of the valve 6 pushes the spring 8 to block the oil flow. As a result, the peripheral gear 2 stops its rotational motions, but continues the orbital motions. Consequently, the rotary power is transmitted to the body 3 by

100%.

If this power transmitting mechanism is combined with a one way clutch gear as shown in Figure 5, it becomes an automatic speed shifting device for an automobile. Therefore, descriptions will be made as follows.

That is, with the valve open as shown in Figure 4, three rotary power transmitting devices which are designed to be activated at 2000 rpm and to be closed at 3000 rpm are connected as shown in Figure 5. Further it is assumed that a first stage gear 19 is 12 T, an output gear 22 is 48 T, an output gear 21 is

40 T, and a second stage gear 24 is 20 T.

In the idle state, the engine revolution speed is 800 rpm. At the starting point, the engine revolution speed becomes more than 2000 rpm, Under this condition, if the input side central gear 13 is made to revolve at 2000 rpm, a first stage central gear

12 and a second stage central gear 14 reach 2000 rpm, owing to the fact that they are connected 9th, 10th and 11th gears. An output shaft 15 of the first stage gear, an output shaft 17 of the second stage gear, and an output shaft 16 of the third (top) stage

gear slowly revolve, owing to the rotary power of the input side central gear 13, the first stage central gear 12 and the second stage central gear 14. However, due to the reduction ratio between the first stage gear 19, the second stage gear 24 and the output gear 21, the revolution of the first stage gear 19 is fastest, while the transmission of the rotary power transmitting torque is realized most voluminously through the first stage gear rotary power transmitting device 18.

Therefore, when the revolution of the first stage gear output shaft 15 reaches 2000 rpm, the valve piston of the first stage gear rotary power transmitting device 18 is slowly closed, with the result that the power transmitting amount is more increased.

Under this condition, if the revolution of the input side central gear 13 is accelerated to over 3000 rpm, the revolution of the first stage gear output shaft 15 is also gradually accelerated.

Consequently, the valve piston of the first stage gear rotary power transmitting device 18 is closed, with the result that the rotary power is transmitted by 100%. Thus when the revolution of the first stage gear 19 is accelerated to 4000 rpm, the revolution of the second stage gear output shaft 17 reaches 2000 rpm, so that the valve of the second stage gear rotary power transmitting device 23 should be activated. When the revolution of the second stage gear 24 reaches 4000 rpm, the revolution of the third stage (top) gear 16 will reach 2000 rpm. When the third stage (top) gear output shaft 16 is accelerated to over 3000 rpm, the valve of the third stage gear rotary power transmitting device

20 is closed, with the result that the input side central gear 13 is directly connected with the third stage (top) gear output shaft 16.

Therefore, when the third stage (top) gear output shaft 16

reaches 3000 rpm, the second stage gear output shaft 17 will reach 6000 rpm while the first stage gear output shaft 15 will reach 12000 rpm. Thus reverse loads are imposed on the first stage gear rotary power transmitting device 18 and on the second stage rotary power transmitting device 23. In order to prevent this phenomenon, one way clutch gears 9 and 11 are provided.

According to the present invention as described above, the bulk is small and the constitution is simple. Therefore, the disorder rate is low, and repair becomes easy, as well as saving the fuel consumption. Further, there is no vibration during the speed shift, and particularly, the device is suitable for large vehicles and heavy duty equipment.