WO1999039116A1

WO1999039116A1 - Transmission system

Info

Publication number: WO1999039116A1
Application number: PCT/GR1999/000009
Authority: WO
Inventors: Manousos Pattakos; John Pattakos; Emmanouel Pattakos
Original assignee: Manousos Pattakos; John Pattakos; Emmanouel Pattakos
Priority date: 1998-01-30
Filing date: 1999-01-28
Publication date: 1999-08-05
Also published as: JP2001520732A; CN1255962A; EP0995057A1; GR980100044A; CN1141502C

Abstract

The rotary motion of an input shaft is firstly altered into a controllable rotational oscillation of an intermediate member and subsequently, by means of an overrunning clutch mechanism, this oscillation is transformed into one way impulses towards output shafts which drive the loads. The connecting mechanism between the input shaft and the intermediate member controls, according to its condition, the amplitude of the angular oscillation of the intermediate member within a minimun/maximum, defining the transmission ratio. Inherent drawbacks like the strong impact loads are eliminated as long as the output shafts drive the loads through proper elastic connections while additional overrunning clutches, secured to the casing, prevent the reverse motion of the output shafts.

Description

-1-

TRANSMISSION SYSTEM In the state of the art, according the patents PCT/JP92/00719, JP60125454, US4109539, DE3226245, US4109539, DE2752937, DEI 122350, FR125297, the rotary motion of an input shaft is first changed into a controllable rotational oscillation of an inteπnediate member and subsequently, by means of an overrunning clutch mechanism, this oscillation is transformed into one way impulses towards an output shaft which drives the load. The connecting mechanism between the input shaft and the inteπnediate member controls, according its condition, the amplitude of the angular oscillation of the intermediate member within a minimum/maximum, defining the transmission ratio. Yet, the output shaft can drive the load not rigidly but through a proper elastic connection while an additional overrunning clutch, secured to the casing, can prevent the reverse motion of the output shaft. Thereby can result a continuously variable transmission system with an essentially improved dynamic behavior with respect to whatever the state of the art can afford.

In FIG 1 and 2 it is shown a crankshaft 5 having a crank pin 6 of controllable throw. Through the connecting rod 44 the rotary motion of the crankshaft 5 is transmitted to the intennediate oscillating member 15 which drives, by means of an overmnning clutch 48, the output shaft 16. In FIG 3 it is shown a flywheel 45, representing the inertia of the load, rigidly secured to the output shaft 16.

In FIG 4 they are shown, simplified, all the constituent parts of the transmission system as it is in the state of the art. The flywheel corresponds to the inertia of the vehicle while the brake corresponds to the various resistance in the motion of the vehicle. There is an input shaft, there is a controllable connecting mechanism that transforms the rotation of the input shaft to rotational oscillation of variable amplitude of an intermediate member, there is also an overrunning clutch between the oscillating member and the output shaft. The transmission ratio changes by controlling the throw of the crank pin 6 of the input shaft 5.

According the state of the art there are several ways to realize this system of continuously variable transmission, but all involve as basic constituents the input shaft, the connecting controllable mechanism, the intermediate oscillating member, the overrunning clutch and the output shaft, even modified. In the system of FIG 4 it is shown all the constituent parts of such a transmission system.

In FIG 5 it is shown the flywheel 45 elastically connected to the output shaft 16. It is also shown an additional overrunning clutch between the casing and the output shaft.

In FIG 6 it is shown, simplified, the whole assembly of the transmission -2- system shown in FIG 4, modified according the present invention. Here, the driven system is elastically connected to the output shaft 16 and an additional oveirunning clutch 49 is inserted between the casing 23 and the output shaft 16 to prevent the reverse motion of the output shaft. In FIG 7 to 12 they are schematically shown the angular velocities and the time intervals of engagement for the mechanisms of FIG 1 to 6. In FIG 1 and 2 the crankshaft 5 rotates with a velocity ωo, shown as a function of time in FIG 7 to 12. The crank pin 6 has a controllable throw which is smaller in the case of FIG 2. The connecting rod 44 connects the pin 14 of the intermediate member 15 to the crank pin 6. The rotary motion of the crankshaft 5 is transformed into oscillation of controllable amplitude Δφ of the intermediate member 15. The instant velocity of the 15 is ωi in FIG 1 and ω in FIG 2, shown as function of time in FIG 7 and 8. Rolers like 26 and springs like 28 fonn an overrunning clutch 48 between the inteπnediate member 15 and the output shaft 16. In the FIG 3 the output shaft 16, shown also in FIG 1 and 2, is secured, by means of inflexible member like 47, to the driven system 45, which is shown as a flywheel, so that the instant angular velocity of both, output shaft 16 and driven system 45, is the same ω₂. The break 50, shown in FIG 4, corresponds to the resistance of the driven system. In FIG 9 it is drawn with continuous line the resulting angular velocity ω₂ of the shaft 16 and of the load 45 of FIG 3. T is the time for a rotation of the crank 5. During each rotation of the crank 5, transfer of energy to the output shaft 16 and to the load 45 takes place only for a very small time interval Δτ. It happens because the driven system looses only a small fraction of its velocity during a rotation of the input shaft. The result is strong impact loads of tremendous amplitude, noise, vibrations, excessive wear and low efficiency. The mean value of CO2 is only a little less than the maximum angular velocity of the intermediate member 15. After each impulse of energy the angular velocity ω₂, due to the various resistance, drops slightly till the next pulse. The transmission ratio is substantially the ratio of the maximum angular velocity of the intermediate member 15 to the mean angular velocity of the input shaft. This ratio changes according the throw of the crank pin 6, as it is shown in FIG 2 where the crank pin 6 shifts closer to the rotation axis of the crankshaft 5 and so Δφ'<Δφ. To change the transmission ratio it is enough to shift the crank pin 6.

In the FIG 5 and 6 the driven system 45 is connected elastically to the output shaft 16 by means of some flat spiral springs like 46, while an additional overπinning clutch 49, made of rollers like 25 and springs like 29, is inserted between the shaft 16 and the immovable casing 23. In FIG 5 the instant angular velocity of the shaft 16 is ω _α, and of the driven system 45 is ω₃, -3- different than ω_2α. In FIG 11 it is drawn with continuous line the angular velocity ω_2α of the output shaft 16 of FIG 5 and 6, it is also drawn with dashed dot line the resulting angular velocity ω₃ of the driven system 45. The additional oveirunning clutch prevents the reverse motion of the output shaft 16. T_α is the time interval, during each rotation of the crank 5, wherein the intermediate member 15 is engaged to the output shaft 16 and energy flows between them. This T_α is about half of the period T, so there is plenty of time to transfer energy f om the crankshaft 5 to the output shaft 16. Even more, energy is transferred to the load all the time. This happens because the elastic connection 46 stores energy while the T_α time interval during each cycle of rotation of the input shaft 5, and offers energy to the load in a substantially continuous way. The loads are impact no more. The transmission ratio is substantially the ratio of the amplitude Δφ of the oscillation of the intermediate member 15 to the necessary 360 degrees for a rotation of the input shaft 5.

The preceding description makes clear that the principle of operation, the inertia loads, the resulting transmission ratio and the flow of energy are radically different from the respective ones of the prior art, which is a consequence of the added constituents. FIG 8, 10 and 12 show respective diagrams of FIG 7, 9 and 11 but for a smaller throw of the pin 6, as shown in FIG 2.

If a second output shaft is driven by the intermediate oscillating member through an additional oveirunning clutch and a fraction of the load is elastically driven by said second output shaft while another oveirurining clutch, inserted between the casing and the second output shaft, prevents the reverse rotation of the second output shaft, then the system performs also the operation of a controllable differential supplying the most of the torque to the slower part of the load.

Claims

-4- CLAIMS What is claimed is:

1. A transmission system comprising: a casing; an input shaft; an output shaft; a rotary oscillating inte╧Çnediate member; a controllable connecting mechanism, connecting said input shaft to said rotary oscillating intermediate member and transforming the rotary motion of said input shaft into rotary oscillation of variable angular amplitude of said rotary oscillating intermediate member; an overrunning clutch between said rotary oscillating intennediate member and said output shaft; characterized in that said output shaft drives the load through an elastic connection while an additional oveirunning clutch, located between said output shaft and said casing, controls the direction of the discharge of said elastic connection, thereby power is transferred to the load smoothly and continuously improving the efficiency and eliminating the impact loads, the noise and the wear.

2. A transmission system according claim 1 characterized in that there is a second output shaft, driven by said rotary oscillating intermediate member through an additional oveirunning clutch inserted between them, said second output shaft drives, though an elastic connection, a fraction of the load while an additional oveirunning clutch, located between said casing and said second output shaft, prevents the reverse rotation of said second output shaft, thereby it is performed also the operation of a controllable differential.

3. Transmission system according claim 1 characterized in that the controllable intermediate mechanism is selected, as regards its masses and their distribution, to improve the total counterbalancing of the system.