Field of the Invention

The present invention relates to clutch system for either fast gearing up with constant torque transmission or fast downshifting with constant torque transmission. Gearing up or down with constant torque transmission is achieved by mechanical clutching during gearing from hydraulic disengagement of one gear to hydraulic engagement with a clutch of another gear.

Background of the Invention

A common technical challenge for all coupling systems is a loss in traction during the switching of gears, due to temporary loss or reduction of the torque transfer. It could be a full loss of torque transfer, like when using manual gears, or a smaller drop using hybrid systems. Many inventions are trying to solve this technical challenge by various alternative means, as described in this section. None of them discloses a simple and reliable coupling system for constant torque transfer during gear shifting.

US3216545A (KURT SCHROTER, published on 1965-1 l-09)”Multiple friction clutches”, discloses a coupling system where friction disks are engaged and disengaged with pushing rods or a diaphragm spring.

US8042672B2 (GRETHEL et al., published on 2011-10-25) discloses a hydraulic ar- rangement for controlling and cooling a twin-clutch transmission of a motor vehicle.

US4022308A (HURST, published on 1977-05-10) discloses axially movable cone members for selective engagement of a clutch with either mating cone member, ena- bling said member or members to be driven in either rotary direction.

US8025138 B2 (YOSHINAGA et al., published on 2011-09-27) discloses some exam- ples of bevelled teeth used in a multi-clutch system.

None of the alternative attempts to a coupling system discloses a simple and reliable mechanical support of torque transfer in between hydraulically coupling out of one gear and hydraulically coupling in another gear. Depending on the rotational configuration of the coupling system relatively to the motor rotation direction, the coupling system is smoothly transferring the torque either during gearing up or during downshifting. Objective of the Invention One objective of the invention is a coupling system for faster and smoother gearing with constant torque. Another objective of the invention is a method of switching gears faster and smoother and with a constant torque. The third objective of this invention is the use of the coupling system for motorized vehicles. Description of the Invention An objective is achieved by a coupling system comprising a flywheel housing (1), an inner and an outer concentric shafts (2) and (3), a first friction disk (4) attached to the inner shaft (2). There is a second friction disk (5) attached to the outer shaft (3). There is a first and a second hydraulic rings (6 and 6a) configured to engage and disengage the first and the second friction discs during gear shifting. The coupling further com- prises a first and a second self-locking disk-shaped plates (7 and 8) configured for me- chanical coupling between hydraulically disengaging one gear and hydraulically engag- ing another gear. Thereby, an additional mechanical clutching is achieved during hydraulic gearing pro- cess, where said mechanical clutching assists constant torque transfer inbetween hy- draulic disengagement of one gear to hydraulic engagement with another gear. A further objective is a fast and smooth gear shifting method. It is achieved by two self- locking discs-shaped plates mechanically engaging or disengaging with the each one of the friction discs, with the friction discs guided in and out of coupling with flywheel housing using self-locking disc-shaped plates and two respective hydraulic rings. The third objective of the invention, use of coupling system and method in motorized vehicles, is achieved, when the coupling system and coupling method of two other ob- jectives are employed in motorized vehicles to achieve fast acceleration with constant torque for gearing up coupling system in vehicles and in order to assist pulling heavy loads and moving uphill for gearing down system in motorized vehicles. Description of the Drawings

Fig. 1 . A cross-sectional full view of the flywheel housing (1).

Fig. 2. A cross-sectional broken view of the flywheel housing (1).

Fig. 3. A cross-sectional view of an outer shaft (3). Fig. 4. Illustration of starting up, when both shafts (2) and (3) are not coupled.

Fig. 5. Illustration of torque transfer with hydraulically coupled first gear.

Fig. 6. Shifting gear hydraulically coupling out one gear and mechanically coupling it in at the same time.

Fig. 7. Illustrates a temporary mechanical coupling ensuring constant torque transfer in between the hydraulically coupled gears.

Fig. 8. Illustration of engaging the higher gear during gearing up.

Fig. 9. Once a higher gear is coupled hydraulically, the mechanic decoupling takes place automatically.

Fig. 10. Higher gear. Fig. 11 . The downshifting.

Fig. 12. Comparison of the novel coupling system wdth DSG and manual gearing.

Detailed Description of the Invention

One embodiment of the invention is directed towards mechanically assisting gearing up process, while gearing down will take place without mechanically supported constant torque transfer. The process of this embodiment is illustrated in figures 1-12. Fig. 1 illustrates a cross-sectional full view of the flywheel housing (1) comprising two concentric shafts (2) and (3), a first and a second friction disks (4) and (5), each move- ably attached to one of the respective shafts, two hydraulic rings (6a and 6) for coupling during gear shifting, and two self-locking disk-shaped plates (7) and (8) configures for mechanical coupling in between hydraulically disengaging one gear and hydraulically engaging another gear.

Fig. 2 illustrates a cross-sectional broken view of the flywheel housing (1), showing that the flywheel housing comprises obliquely cut teeth-like structures (“bevelled teeth”) that are complimentary to and capable of locking with the obliquely cut teeth- like structures (“bevelled teeth”) on one of the disc surfaces of a self-locking disc- shaped plate. This locking principle is known from kick-starters for motorbikes.

Fig. 3 shows a cross-sectional view of an outer shaft (3) with a zone with second struc- tures (10) on the outer surface of the outer shaft, said zone expanding only where a friction disk (5) and a self-locking disk-shaped plate (8) should interlock with respective axes during rotation, and the first structures on the inner surfaces of disk (5) and plate (8) facing the shaft. Here, the first and second structures are illustrated as splines. When the first and the second structures are interlocked, the interlocked elements rotate to- gether, but the disk (5) and the plate (8) is still moveable along the axis of the shaft, and capable of disengaging from the shaft when pushed out of the zone with second struc- tures on the outer surface of the shaft.

Fig. 4 is illustrating starting up the gearing process, when both shafts (2) and (3) are not coupled, both disks (4) and (5) are not engaged, both plates (7) and (8) are not engaged, and rotating engine only engages the flywheel housing and the hydraulic pressure rings.

Fig. 5 illustrates torque transfer when a first gear is coupled hydraulically.

Fig. 6 illustrates shifting gears. Process starts with hydraulically coupling out one gear and mechanically coupling it in at the same time. This is done by simultaneously hy- draulically disengaging the first friction disk (4) and hydraulically pushing the first self- locking disc-shaped plate (7) into the engagement with flywheel housing, said engage- ment locking when engine pulls. Fig. 7 illustrates a temporary mechanical coupling, ensuring the torque transfer in be- tween the hydraulically coupled gears. The engine pulls the flywheel housing and me- chanically engaged to it plate (7). Plate (7) is also splined to the shaft (2) in this position, so the torque is transferred to the shaft.

Fig. 8 illustrates engaging the higher gear during gearing up. Once the hydraulic pres- sure ring is activated on gear shifting, the hydraulic pressure ring engages the friction disc, creating friction between the said disc and the flywheel housing and the hydraulic pressure ring, and the torque is transferred to the outer shaft.

Fig. 9 illustrates that, once a higher gear is coupled hydraulically, the mechanic decou- pling takes place automatically, as the engines rpm (round per minute) slightly decrease when the engine is engaged with the outer shaft, and the self-locking disc-shaped plate (7) will rotate relatively faster and therefore will pop out of the engagement with the fly-wheel housing due to the orientation of the obliquely cut teeth-like structures. Dis- engagement of the mechanical coupling simultaneously with coupling of the higher gear ensures the constant torque transition during gearing up.

Fig. 10 illustrates coupling of a higher gear. Once the plate (7) on the inner shaft is disengaged from the fly-wheel housing, the torque transfer is ensured by hydrodynamic pressure ring coupling of the flywheel housing and the second friction disc (5) inter- locked with the outer shaft by using first and second structures on the surfaces of the friction disc and the shaft, for example, splines.

Fig. 1 1 illustrates the downshifting gears process. During the downshifting, the hydrau- lic pressure is removed from the coupled shaft and applied to another shaft. The down- shifting to lower gear is not mechanically supported in couplings for upgrading gear with constant torque, where the plate on the inner shaft locks in the direction of rotation of the engine.

Fig. 12. Comparison of the novel coupling system with DSG (traditional double cou- pling) and manual gearing (single coupling), where the pulling force and time are plot- ted for all 3 coupling systems under comparison. In one embodiment, a coupling system comprises a flywheel housing (1), an inner and an outer concentric shafts (2) and (3), a first friction disk (4) attached to the inner shaft (2), a second friction disk (5) attached to the outer shaft (3), a first and a second hydrau- lic rings (6 and 6a) for engaging and disengaging the first and the second friction discs during gear shifting, wherein the coupling further comprises a first and a second self- locking disk-shaped plates (7 and 8) for mechanical coupling between hydraulically disengaging one gear and hydraulically engaging another gear.

In another embodiment, the flywheel housing (1 ) comprises a first area (10) and second area (11) com-prising obliquely cut teeth-like structures, the first and the second self- locking disk-shaped plates (7) and (8) comprising areas (12) and (13), respectively, with obliquely cut teeth-like structures complimentary to obliquely cut teeth-like structures of the respective first area (10) and second area (11) of the fly-wheel housing (1), where the obliquely cut teeth of the first self-locking disk-shaped plate in area (12) engages with the obliquely cut teeth-like structures in the first area (10) of the flywheel housing, when pressed together in rotation, and the obliquely cut teeth of the second self-locking disk-shaped plate in area (13) engages with the obliquely cut teeth-like structures in the second area (11) of the flywheel housing, when pressed together in rotation.

In a third embodiment, the first and second friction disks (4 and 5) and the first and second self-locking disk-shaped plates (7 and 8) are moveably engageable to the respec- tive inner or outer shafts (2 or 3, respectively), so that said disks (4 and 5) and plates (7 and 8) can engage to said shafts (2 or 3, respectively) on rotation while being freely moveable laterally along said shafts (2) or (3).

In yet a further embodiment, the first and second friction disks (4) and (5) and the first and second self-locking disk-shaped plates (7) and (8) comprise first structures (9) on the inner surfaces oriented towards respective inner or outer shafts (2) and (3), and the outer surfaces of inner and outer shafts comprise zones (14) with second structures on the outer surfaces, said zones expanding only where the disks and plates should inter- lock with respective shafts (2) and (3) during rotation, the first structures (9) and second structures in zones (14) being formed to engage friction discs (4) and (5) and self-lock- ing disk-like plates (7) and (8) to the respective inner or outer shafts (2) and (3), said first structures (9) being complimentary to said second structures in zones (14) in shape, to ensure locking the friction disks (4) and (5) and self-locking disk-shaped plates (7) and (8) to the respective inner or outer shafts (2) and (3) on rotation when being inside respective zone (14), while still allowing the lateral movement of friction disks (4) and (5) and self-locking disk-shaped plates (7) and (8) along the respective inner or outer shaft (2) and (3) in and out of said zones (14).

In a further embodiment, said first structures (9) and said second structures in zones (14) are splines.

In a further embodiment, the area (12) with obliquely cut teeth-like structures of the first self-locking disk-shaped plate (7) is engaging and locking with the obliquely cut teeth-like structures in the first area (10) of the flywheel housing (1) in a first rotational direction, the obliquely cut teeth -like structures in area (13) of the second self-locking disk-shaped plate (8) is locking with the obliquely cut teeth-like structures in the second area (11) of the flywheel housing (1) in a second rotational direction, the second rota- tional direction being counter direction to said first rotational direction, and the gearing process so mechanically supported by the coupling system is gearing up.

In yet another embodiment, the obliquely cut teeth-like structures in areas (10), (11), (12) and (13) are manufactured to lock in direction reversed compared to gearing up process, so that the obliquely cut teeth-like structures in the first area (12) of first self- locking disk-shaped plate (7) is locking with the obliquely cut teeth-like structures in the first area (10) of the flywheel housing (1) in rotation, the obliquely cut teeth-like structures of the area (13) of the second self-locking disk-shaped plate (8) is locking with the obliquely cut teeth-like structures in the second area (11) of the flywheel hous- ing (1) in rotation, and the gearing process so mechanically supported by the coupling system is gearing down.

A further embodiment is a method to gear up using the disclosed coupling system, gear- ing up comprising the following sequential steps: a. Starting up: no shafts attached, no friction disks attached, an engine engages and rotates only the flywheel housing (1) and hydraulic pressure rings (6) and (6a); b. Engagement of a first gear: the hydraulic pressure ring (6) for the inner shaft (2) is activated and the first friction disk (4) on the inner shaft (2) is pressed into the flywheel housing (1), the first structures (9) on the inner surface of the first fric- tion disk engaging the second structures on the outer surface in zone (14) of the inner shaft (2) and thus locking first friction disk (4) to the inner shaft (2) and causing the inner shaft (2) to rotate, and the torque is transmitted; c. Upgrading gear: i. Hydraulic coupling out of low gear and mechanical engagement of low gear takes place at the same time, as the hydraulic pressure on the first friction disk (4) stops at the same time as a mechanical gearing of the low gear is performed by hydraulic ring (6) pushing the first self-locking disc-shaped plate (7) into engagement with the first area (10) of the fly- wheel housing (1), and, as the engine pulls, the engagement between the first self-locking disk-like plate (7) and the flywheel housing (1) locks, enabling temporary mechanical engagement and torque transfer during the transition from a low gear to a high gear; motor ro-tates the first fric- tion disc (4) engaged with the inner shaft (2) by interlocking the first structures (9) of the first friction disc (4) and second structures in zone (14) on the outer surface of the inner shaft (2), and the torque is trans- ferred; ii. Hydraulic engagement of higher gear is performed when the hydraulic pressure ring (6a) pushes the second friction disk (5) on the outer shaft (3), causing friction between second friction disk (5), hydraulic pressure ring (6a) and flywheel housing (1), and torque is transferred. iii. Mechanical disengagement of low gear occurs when the gear change oc- curs, because the rotational speed of the engine drops, causing the first self-locking disc-shaped plate (7) to 'pop out' of the engagement with the flywheel housing (1) as the engine be-gins to pull on the outer shaft (3), ensuring constant torque transfer and resulting in the first self-locking disc-shaped plate (7) rotating relatively faster than the flywheel housing (1), whereby pushing itself out of engagement due to the orientation of the teeth, and because there is no pressure on the back of the first self- locking disc-shaped plate (7), it will pop out of the engagement with fly- wheel housing (1) and will be inactive. f. Coupling in a second gear happens hydraulically, once the first self-locking disc (7) on the inner shaft (2) has popped out and torque is transferred using the hydrau- lic pressure ring (6a) on the outer shaft (3). g. Downshifting: a. Hydraulic engagement, high gear; b. Hydraulic engagement, low gear.

Another aspect of the invention is a method to gear down wherein the teeth-like struc- tures on both areas (10) and (11) on the flywheel housing (1) and in areas (12) and (13) on the respective plates (7) and (8) are manufactured to interlock in direction reversed com-pared to the coupling system for gearing up, thus mechanically assisting the hy- draulic gearing process during downshifting: a. Starting up: no shafts are atached, no friction disks are attached, and an engine operates rotating only the flywheel housing (1) and hydraulic pressure rings (6 and 6a); b. Hydraulic engagement of the first gear; c. Hydraulic coupling of a higher gear does upgrading gears. d. Downshifting. i. Hydraulic coupling out of higher gear and mechanical engagement of a lower gear takes place at the same time, as the hydraulic pressure on the second friction disk stops and a mechanical gearing of the higher gear is performed by hydraulic ring (6a) pushing the second self-locking disc-shaped plate (8) into engagement with the second area (11 ) of the flywheel housing (1 ), and, as the engine pulls, the engagement between the second self-locking disk-like plate (8) and area with oblique cut teeth-like structures (11) on the flywheel housing (1) locks; ii. The temporary mechanical engagement ensures torque transfer in the transition from the higher gear to the lower gear: motor rotates the second friction disc (5) engaged with the outer shaft (3 ) by interlocking the first structures (9) of the second friction disc (5) and the zone with second structures (14) on the outer surface of the outer shaft (3), ensuring torque transfer; iii. Hydraulic engagement of lower gear is performed when the hydraulic pressure ring (6) pushes the first friction disk (4) on the inner shaft (2), causing friction between the first friction disk (49, hydraulic pressure ring (6) and flywheel housing (1), and torque is transferred; iv. Mechanical disengagement of higher gear occurs when the gear change occurs, because the rotational speed of the engine will increase, causing the second self-locking disc-shaped plate (8) to 'pop out' of the engagement with the flywheel housing (1) as the engine begins to pull on the inner shaft (2), thereby, ensuring constant torque trans- fer and causing the second self-locking disc-shaped plate (8) to rotate relatively faster than the flywheel housing (1), whereby pushing itself out of the engagement with hous- ing (1) due to the orientation of the teeth, and, as there is no pressure on the back of the second self-locking disc-shaped plate (8), it will pop out of the engagement and will be inactive.

The last aspect of the invention is the use of the coupling systems and coupling methods as disclosed in other aspects in motorized vehicles, in order to achieve fast acceleration with constant torque for gearing up systems and method and to assist pulling heavyloads and moving uphill for gearing down systems and method according to other as- pects above.