Power plants – Pressure fluid source and motor – Coaxial impeller and turbine unit
Reexamination Certificate
1999-01-07
2001-04-03
Look, Edward K. (Department: 3745)
Power plants
Pressure fluid source and motor
Coaxial impeller and turbine unit
C060S363000
Reexamination Certificate
active
06209320
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a stepless countinuously variable transmission system.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 3,948,048 (Lifka) relates to a fluid drive which has a three coaxial cylinders, the outer of which is fixed to an output shaft and the inner to an input shaft. The intermediate cylindrical member has vanes on either side for interaction with vanes on the outer and inner cylinders. The action is described basically in lines 52 to 62 of column 2 of the specification and may be shortly described as follows:
rotation of the input shaft 24 causes rotation of cylinder 12,
its vanes 29 cause the fluid in space 42 to rotate and,
its vanes 25 then cause the cylinder 14 to rotate.
The fluid is trapped in the casing and the rotational forces cause frictional action or viscous drag on the vanes thus imparting the desired rotation.
In the present invention, the inefficiency of this type of action is recognized and reliance is placed on hydrodynamic principles involving changes in angular momentum, which allow for more efficient transfer of forces. The fluid is not trapped in the spaces between successive cylinders but rather is given an inwardly or outwardly directed motion so that the desired changes in angular momentum are realized.
U K Patent 607 4365 (Lombardini) is a similar arrangement to that of Lifka if one dissociates oneself with the clutch portion of the arrangement. In essence this invention is a combination of clutch and fluid transmission, the object being to maintain efficiency of the transmission on slipping of the clutch. In FIG. 2 of the Lombardini patent an arrangement very similar to that of Lifka is shown in so far as concentric sets of vanes are provided to “throw out the transmission fluid into the adjacent set of oppositely inclined vanes” from inside to outside (or vice versa). There are three sets of vanes for the driving member and two for the driven member.
U.S. Pat. No. 1,428,586 (Garrison) also provides an annular fluid channel with series of annular blades for frictional transmission of power from the driving to the driven shaft.
Swiss patent 86251 may appear at first glance to involve all angular impingement action by virtue of the provision of an inlet (g) and an outlet (h) for the fluid. However, it is clear that these are merely for the drainage of fluid and refilling purposes. Reference to FIG. 1 will show that the action is similar to all of the above inventions i.e. that of viscous drag, the fluid of these prior inventions moving with the shafts and their vanes and not, as in the stepless transmission system of the present invention, interacting with concentric cages allowing for the required changes in angular momentum.
SUMMARY OF THE INVENTION
According to the invention a stepless countinuously variable transmission system including a casing which houses an input and an output shaft that are connected by a series of concentric cages, some of the cages being fixed to the output shaft and some to the input shaft whilst remaining free to rotate on the other shafts respectively; the cages comprising or including series of blades adapted to interact with a transmission medium which is moved in a predetermined direction or directions in the casing between an inlet and an outlet, whereby the blades experience the changes in angular momentum of the transmission medium.
In one form of the invention the cages alternate between being rigidly attached to the input and output shafts and act in pairs and assuming for the sake of illustration that the outer cage of a pair is driven by an input shaft, the inner cage would then drive the output shaft.
As the fluid passes through an arbitrary individual couple, the outer cage increases the angular momentum of the fluid. The energy imparted to the fluid by this change in angular momentum is then extracted from the fluid by the inner cage of that couple. Considering the flow of an infinitesimal small portion of fluid through the drive, it is evident that the energy extracted from the particle of fluid can be increased by increasing the number of couples or stages thereof. The final output power is the sum of the power extracted from the fluid by the inner cages of the individual stages.
The stepless transmission system of the invention is capable of extracting more work per unit mass of fluid than existing fluid couplings or torque converters. In existing fluid couplings and torque converters, a unit mass of fluid experiences just one reversal in angular momentum, consequently any residual angular momentum of the fluid is not utilized unless additional extraction devices are incorporated. The coupled cage system of the present invention allows for more reversals of angular momentum in proportion to the number of stages used.
For maximum power transmission it has been found that the system should operate in a completely drowned state i.e. all cages should be interacting with the fluid at all times during the transmission of power.
The transmission of power can be controlled by suitable control of the fluid flow through the transmission system.
Where the cages alternate as regards their relative location, either input or output related, the curvature of the blades are opposite in sense. The curvature of the blades can be defined by two angles (inlet and outlet) that are determined according to the required changes in angular momentum of the fluid.
REFERENCES:
patent: 3948048 (1976-04-01), Lifka
patent: 4391096 (1983-07-01), Polzer et al.
2001 Transmission Inc.
Lazo Thomas E.
Look Edward K.
Young & Thompson
LandOfFree
Variable torque converter does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Variable torque converter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Variable torque converter will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2549554