Rotary kinetic fluid motors or pumps – Method of operation
Reexamination Certificate
1999-01-08
2001-05-29
Ryznic, John E. (Department: 3745)
Rotary kinetic fluid motors or pumps
Method of operation
C415S090000, C416S19800R
Reexamination Certificate
active
06238177
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to an apparatus used to transmit motive force between a fluid and a plurality of spaced apart rotatable members. The apparatus may be used to transmit the motive force from a fluid to the spaced apart members or, alternately, from the spaced apart members to the fluid.
BACKGROUND OF THE INVENTION
Prandtl layer turbines were first described by Nikola Tesla in U.S. Pat. No. 1,061,206 (Tesla). For this reason, these turbines are sometimes referred to as “Tesla Turbines”. FIGS. 1 and 2 show the design for a prandtl layer turbine as disclosed in Tesla. As disclosed by Tesla, a prandtl layer turbine 10 comprises a plurality of discs 12 which are rotatably mounted in a housing 14. Housing 14 comprises ends 16 and ring 18 which extends longitudinally between ends 16. Discs 12 are spaced apart so as to transmit motive force between a fluid in housing 14 and rotating discs 12.
The discs 12, which are flat rigid members of a suitable diameter, are non-rotatably mounted on a shaft 20 by being keyed to shaft 20 and are spaced apart by means of washers 28. The discs have openings 22 adjacent to shaft 20 and spokes 24 which may be substantially straight. Longitudinally extending ring 18 has a diameter which is slightly larger than that of discs 12. Extending between opening 22 and the outer diameter of disc 12 is the motive force transfer region 26.
The transfer of motive force between rotating discs 12 and a fluid is described in Tesla at column 2, lines 30-49. According to this disclosure, fluid, by reason of its properties of adherence and viscosity, upon entering through inlets 30, and coming into contact with rotating discs 12, is taken hold of by the rotating discs and subjected to two forces, one acting tangentially in the direction of rotation and the other acting radially outwardly. The combined effect of these tangential and centrifugal forces is to propel the fluid with continuously increasing velocity in a spiral path until it reaches a suitable peripheral outlet from which it is ejected.
Conversely, Tesla also disclosed introducing pressurized fluid via pipes 34 to inlets 32. The introduction of the pressurized fluid would cause discs 12 to rotate with the fluid travelling in a spiral path, with continuously diminishing velocity, until it reached central opening 22 which is in communication with inlet 30. Motive force is transmitted by the pressurized fluid to discs 12 to cause discs 12 to rotate and, accordingly, shaft 20 to rotate thus providing a source of motive force.
Accordingly, the design described in Tesla may be used as a pump or as a motor. Such devices take advantage of the properties of a fluid when in contact with the rotating surface of the discs. If the discs are driven by the fluid, then as the fluid passes through the housing between the spaced apart discs, the movement of the fluid causes the discs to rotate thereby generating power which may be transmitted external to the housing via a shaft to provide motive force for various applications. Accordingly, such devices function as a motor. Conversely, if the fluid in the housing is essentially static, the rotation of the discs will cause the fluid in the housing to commence rotating in the same direction as the discs and to thus draw the fluid through the housing, thereby causing the apparatus to function as a pump or a fan. In this disclosure, all such devices, whether used as a motor or as a pump or fan, are referred to as “prandtl layer turbines” or “Tesla turbines”.
Various designs for prandtl layer turbines have been developed. These include those disclosed in U.S. Pat. No. 4,402,647 (Effenberger), U.S. Pat. No. 4,218,177 (Robel), U.S. Pat. No. 4,655,679 (Giacomel), U.S. Pat. No. 5,470,197 (Cafarelli) and U.S. Reissue Pat. No. 28,742 (Rafferty et al). Most of these disclosed improvements in the design of a Tesla turbine. However, despite these improvements, Tesla turbines have not been commonly used in commercial environment.
SUMMARY OF THE INVENTION
In accordance with the instant invention, there is provided a turbine comprising:
(a) a first housing having a first shaft rotatably mounted in the housing;
(b) a plurality of first spaced apart discs having an outer diameter and mounted on the first shaft and rotatable therewith, each first disc having a radial inner end defining an inner opening, a radial outer end and a pair of opposed surfaces extending therebetween;
(c) a second housing having a second shaft rotatably mounted in the housing; and,
(d) a plurality of second spaced apart discs having an outer diameter and mounted on the second shaft and rotatable therewith, each second disc having a radial inner end defining an inner opening, a radial outer end and a pair of opposed surfaces extending therebetween, the outer diameter of at least some of the first spaced apart discs is less than the outer diameter of at least some of the second spaced apart discs.
In accordance with the instant invention, there is also provided an apparatus comprising:
(a) a plurality of first spaced apart members rotatably mounted to transmit motive force between a fluid and the spaced apart members, the spaced apart members having an upstream end and a downstream end; and,
(b) a plurality of second spaced apart members rotatably mounted to transmit motive force between the fluid and the spaced apart members, the spaced apart members having an upstream end and a downstream end,
each of the first and second spaced apart members has a centre and an outer edge, and the distance between the centre and the outer edge of at least some of the first spaced apart members is less than the distance between the centre and the outer edge of at least some of the second spaced apart members.
In one embodiment, the first and second housings comprise a single housing, the first and second shafts comprise a single shaft.
In another embodiment, each of the first and second spaced apart discs has an outer diameter, and the outer diameter of each of the first spaced apart discs is less than the outer diameter of each of the second spaced apart discs.
In another embodiment, the first spaced apart discs rotate at a different speed to the second spaced apart discs and may rotate at a faster speed to the second spaced apart discs.
In another embodiment, the first spaced apart discs may be at least partially nested or fully nested within the second spaced apart discs or positioned in series with the second spaced apart discs. The first spaced apart discs may be positioned between the opposed ends of the second spaced apart members or downstream of the first spaced apart member of the second spaced apart members. In each case, the first spaced apart discs may be coaxially mounted with the first spaced apart discs.
In another embodiment, the first spaced apart discs are positioned adjacent the upstream end of the second spaced apart discs.
In accordance with the instant invention, there is also provided an apparatus comprising:
(a) a first means for transmitting motive force between a fluid and a first plurality of rotatable spaced apart members; and,
(b) a second separate means for transmitting motive force between a fluid and a second plurality of rotatable spaced apart members,
each rotatable member having a pair of opposed surfaces, the surface area of the opposed surfaces of at least some of the rotatable members of the first means being less than the surface area of the opposed surfaces of at least some of the second means.
The first means may be positioned at least partially internal of the second means or in series with the second means.
In use, the first and second spaced apart members may rotate at different speeds.
The surface area of the opposed surfaces of each of the first rotatable members may be less than the surface area of the opposed surfaces of each of the second rotatable members.
In accordance with the instant invention, there is also provided a method for transmitting motive force between a fluid and rotatable spaced apart members comprising:
(a) passing the fluid through a first plur
Conrad Helmut Gerhard
Conrad Wayne Ernest
Szylowiec Ted
Bereskin & Barr
Fantom Technologies Inc.
Mendes da Costa Philip C.
Ryznic John E.
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