Abstract:
A method and system for propelling or sustaining marine vessels and aircraft. A propulsive force is developed in a gaseous or liquid fluid as a result of rotation of two pairs of generally parallel blades around two perpendicular intercrossed axes with the same speed. The blades are mounted with variable angles of incidence in the planes of rotation around one of the axis and are rotated together with this axis around the second axis. As a result, the blades work simultaneously both in a paddling manner and as a screw propeller with both sides of the blades being used consecutively as working surfaces. In preferred embodiments of the propulsion apparatus, the blades are mounted on a rotated gearbox which is mounted on a hollow driving shaft. The gearbox includes planetary bevel gear engagement with sun gears mounted on a support coaxially to the hollow driving shaft. The propulsion system can include two or more propulsion apparatus with parallel driving shafts rotated in opposite directions for developing a unidirectional propulsive force.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation-in-part of application Ser. No. 09/620,532 filed on Jul. 20, 2000, now a U.S. Pat. No. 6,224,441 which is continuation-in-part of application Ser. No. 09/479,891 filed on Jan. 10, 2000 which is now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to improvements in propeller systems, and more particularly, it pertains to a new method and system for developing a propulsive force in a gaseous or liquid fluid that can be used for propulsion or sustaining aircraft, marine vessels, and land vehicles, such for example, as snowmobiles, etc. Numerous other applications can be derived from the use of this invention, for example in designing apparatus for moving gaseous or liquid fluids such as fans, pumps. etc. 
     2. Description of the Prior Art 
     Historically, various propeller and paddling systems have been developed for propulsion of different types of vehicles by movement of water or air in opposite direction to the movement of the vehicle. Although, at the present time, screw type propellers are the most common form of marine and aircraft propulsion, they have a number of disadvantages. Because the propeller blades are oriented at certain angles to the direction of the rotation, a lot of energy is being lost to friction with air or water, wake forming, vortices, cavitation, etc. The screw propellers are also relatively noisy, which may be undesirable in many situations, such as for submarines, for fishing or pleasure boats, etc. 
     Many improvements of the screw propellers have been suggested throughout the years. Numerous patents and researches have been devoted to development of propeller systems wherein the propeller blades are pivoted simultaneously with rotation of the driving shaft and to the problem of optimizing such cyclic variations of the orientation of individual blades. Some of such systems utilize rotation of propeller blades or paddles not only around the axis of the driving shaft but also around complementary axes of rotation for more effective exertion of propulsive force. The basic concept presented in these systems is that the usable propulsive force is developed as a result of rotating the blades around two axes of rotation with variable orientation of the rotated blades relative to the driving shaft. 
     Propulsion apparatus are known (U.S. Pat. No. 1,284,282 to Fitzpatrick, U.S. Pat. No. 1,450,454 to Roney, U.S. Pat. No. 1,667,140 to Clark, U.S. Pat. No. 1,923,249 to Abram) wherein blades of feathering type extend radially from the driving shaft and are rotated around radial axes simultaneously with rotation of the driving shaft. In the paddling position, the blades are held in a plane parallel to the axis of the driving shaft and in the feathering position, the blades are held in a plane perpendicular to the axis of the driving shaft. A serious drawback of such systems is that, in the process of changing from one position to the other, the blades have to be rotated 90 degrees around their longitudinal axes with a considerable resistance of the fluid and low paddling and propulsion efficiency during such rotation. That is why such systems have low propulsion efficiency in comparison with screw type propellers. 
     There are also known propulsion apparatus wherein the propeller blades are oriented and rotated in the planes parallel to the driving shaft (U.S. Pat. No. 3,270,820 to Frazier, British patent No. 217,223 to Pensovecchio). Although having advantages in respect to the propellers with feathering blades, such apparatus with only two blades mounted in a plane perpendicular to the propeller shaft also have low efficiency and irregular power consumption. Different combinations of such propulsion apparatus are cumbersome and the mechanisms employed to effect their operations are far too complicated to render them practical. For these reasons, a limited success has been obtained by such type of apparatus. 
     The invention seeks to overcome the deficiencies of known propulsion systems and to benefit from the advantages that may be expected from the new method and system. 
     The object of the invention is to provide a reliable propulsion system for marine vessels, aircraft and land vehicles with improved propulsion and energy efficiency. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention is based on my discovery that an effective propulsive force in a liquid or gaseous fluid can be developed by rotating a driving shaft with four blades which are simultaneously rotated around two intercrossed axes which are perpendicular to each other in a plane perpendicular to the axis of the driving shaft. Each blade is oriented so that it is always held in a plane generally perpendicular to the axis around which it is rotated. The blades and the driving shafts are interconnected so when two parallel blades, which are rotated around one of the intercrossed axis, are oriented in the same direction parallel to the axis which is perpendicular to the driving shaft, the other two parallel blades, which are rotated around the other of the intercrossed axis, are oriented in opposite directions parallel to the axis of the driving shaft. Each two adjacent blades mounted in perpendicular planes are rotated in different directions (clockwise and counterclockwise). It was discovered that it is possible to rotate four such blades around perpendicular intercrossed axes without interfering with each other simultaneously around the driving shaft and the perpendicular intercrossed axes with the same speed. During such double rotations, the radial extensions of the blades relative to the driving shaft are changing as a function of the angle of rotation. As a result, both sides of the blades are being used consecutively as paddling surfaces and the speed of paddling motion of the blades is changing during each stroke, resembling a fishtail or frog-leg action of the aquatic nature. Preferably, the blades have airfoil sections. 
     In preferred embodiments of the invention, the blades are constrained by the planetary gear engagements to rotate with the same speed around the axis of the driving shaft and around the intercrossed axes of the radial shafts mounted in rotated gear-boxes. Each gear-box comprises four radial shafts on which planet angle mitre gears and blades are mounted. The sun gears of the planetary engagements are mounted coaxially to the driving shafts. 
     In addition, simultaneously with the paddling process, the rotated blades can work as a double screw propeller if they are mounted with angles of incidence in the planes of rotation around the radial axes. Because the orientations of the blades are constantly changed during the rotation of the driving shaft, the angles of incidence of them must be variable. For this purpose, the blades may be mounted on the radial shafts with ability to swing around the axes perpendicular to these shafts. They can be swung by circular cams mounted coaxially with the radial shafts. 
     For developing a unidirectional propulsive force, the propulsion system may include two or more parallel driving shafts rotated in opposite directions. It is possible to mount the driving shafts in vertical or horizontal positions in a close proximity to each other and/or to a driven vehicle by the sides where the rotated blades are parallel to the driving shaft. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The objects and features of the present invention will become apparent from the following description taken in conjunction with the preferred embodiments thereof with reference to the accompanying drawings, in which: 
     FIG. 1 is a schematic view from the stern of a boat with a preferred embodiment of the propulsion system and a fragmentary cross-section on the lines  1 — 1  of FIG.  2 . 
     FIG. 2 is a cross-sectional view on the lines  2 — 2  of FIG.  1 . 
     FIG. 3 is a schematic fragmentary cross-sectional top plan view on a boat with a preferred embodiment of the propulsion system on the lines  3 — 3  of FIG.  1 . 
     FIG. 4 schematically illustrates another embodiment of the propulsion apparatus with the blades mounted on the radial shafts with variable angles of incidence. 
     FIG. 5 is a cross-sectional view on the lines  5 — 5  of FIG.  4 . 
     FIG. 6 is a cross-sectional view on the lines  6 — 6  of FIG.  4 . 
     FIG. 7 is a schematic fragmentary cross-sectional view from the stern of a boat with another embodiment of propulsion system with the driving shafts mounted on both sides of the boat. 
     FIG. 8 is a cross-sectional view on lines  8 — 8  of FIG. 9 of a propulsion system for a marine vessel with an alternative design of the gear-boxes. 
     FIG. 9 is a cross-sectional view on the lines  9 — 9  of FIG. 8 
     FIG. 10 is a schematic view from the stern of a boat with another embodiment of the propulsion system having a fragmentary cross-section on the lines  10 — 10  of FIG.  11 . 
     FIG. 11 is a cross-sectional view on the lines  11 — 11  in FIG.  10 . 
     FIG. 12 is a schematic cross-sectional side elevation view of a vertical takeoff and landing aircraft with a propulsion system of the preferred embodiment on the lines  12 — 12  of FIG.  13 . 
     FIG. 13 is a schematic fragmentary cross-sectional top plan view on the lines  13 — 13  of FIG.  12 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invented propulsion system can be used in outboard motor applications for marine vessels (FIGS. 1,  2 ,  3 ) or in stern drive applications where the engine is enclosed within the hull of the vessel (FIGS. 7,  10 ,  11 ). Identical details have the same indications in different embodiments. 
     The propulsion system illustrated in FIGS. 1,  2 ,  3  includes two vertical hollow driving shafts  11  which are rotatably mounted in housings  12  and can be rotated in opposite directions by an internal combustion engine  13  through gear engagements  14 ,  15  (or any other type of drive). Planetary gear-boxes  16  are mounted on the hollow driving shafts  11 . An axial support means  17  is fixed coaxially to the hollow driving shaft  11 . Each gear-box  16  comprises four radial shafts  18 ,  19 ,  20  and  21  which are perpendicular to each other in a plane perpendicular to the axis of the driving shaft  11 . Each of the radial shafts can be rotated in two bearings, one of which ( 22 ,  23 ,  24  or  25 ) is mounted in the wall of the gear-box and another in the central part of the gear-box (not shown). Two sun bevel mitre gears  26  and  27  are mounted on the axial support means  17 . Two planet bevel mitre gears  28  and  29  are mounted on the radial shafts  18  and  19 , respectively, so that they are engaged with the sun bevel mitre gear  26 . Another two planet bevel mitre gears  30  and  31  are mounted on the radial shafts  20  and  21 , respectively, and are engaged with the sun bevel mitre gear  27 . The planetary gear-boxes  16  can be filled with a lubricating oil. 
     Blades  32 ,  33 ,  34  and  35  are mounted on the ends of radial shafts  18 ,  19 ,  20  and  21 , respectively, so that each of these blades is generally lying in a plane perpendicular to the axis of the radial shaft on which it is mounted. The blades are oriented in such a way that when two of them ( 34  and  35 ) extend in the same direction perpendicular to the driving shaft  11 , the other two blades ( 32  and  33 ) extend in opposite directions parallel to the driving shaft  11 . Preferably, the blades  32 ,  33 ,  34 ,  35  have airfoil sections. 
     In operation, the planetary gear boxes  16  are rotated together with the blades  32 ,  33 ,  34 ,  35  in the directions indicated by arrows A and B (FIG.  3 ). Simultaneously, the blades  32 ,  33 ,  34 ,  35  are constrained by the planetary engagements of angle mitre gears  26 ,  28 ,  29  and  27 ,  30 ,  31  to rotate around the intercrossed axes of the radial shafts  18 ,  19 ,  20 ,  21  with the speed of rotation of the hollow driving shafts  11 . The blades adjacent to each other in the perpendicular planes are rotated in opposite directions (clockwise and counterclockwise) not interfering with each other. As a result of such double rotation, the blades operate in a paddling fashion with their radial extensions relative to the axis of the hollow driving shaft being changed as a function of the angle of rotation. The blades  34  and  35  which are shown in a horizontal paddling position perpendicular to the longitudinal axis of the boat  10  have the maximum extensions and, as a result, the biggest swept surface, while the other two propeller blades  32 ,  33  are in vertical positions parallel to the driving shafts  11  in the planes parallel to the longitudinal axis of the boat. After the next 90 degree rotation of the driving shafts  11 , the blades  32 ,  33  come to the horizontal positions perpendicular to the longitudinal axis of the boat and the other two blades  34 ,  35  come to the vertical positions (not shown). The positions of the blades after 45 degree rotation of the driving shaft is shown in dashed lines. Each pair of blades, rotated around the same radial axis in opposite directions, are parallel to each other in horizontal positions. The circumferential velocity of the blades relative to the driving shafts  11  gradually increases when the orientations of the blades are changed from vertical to horizontal positions. As a result, an additional acceleration and propulsion force is produced during each of the paddling stroke of the blades. 
     The blades  32 ,  33 ,  34 ,  35 , which are rotated around horizontal axes by radial shafts  18 ,  19 ,  20 ,  21 , respectively, in opposite directions indicated by the arrows C, D, E, F, can be used as the blades of a double screw propeller. For this purpose, the blades may be mounted with angles of incidence in the planes of rotation around the horizontal axes. Because the orientations of the blades relative to the longitudinal axis of the boat  10  are changing during the rotation of the driving shafts with both surfaces of the blades used consecutively for paddling, the angles of incidence of the blades must be variable. For this purpose, each of the blades is mounted on the radial shaft with ability to swing in the bearings  36  around the axis  37  which is fixed to the radial shaft in perpendicular direction, as illustrated in FIGS. 4-6. Four circular cams  38  are mounted on the gear-boxes  16  coaxially to the radial shafts  18 ,  19 ,  20 ,  21  and the followers  39 ,  40  are fixed to each of the blades. The cams  38  are profiled so that during the rotation of the radial shafts, the angles of incidence of the blades are changed in accordance with the positions of the blades. In vertical positions, the angles of incidence of the blades ( 32 ,  33 ) are zero. When the blades ( 34 ,  35 ) extend perpendicular to the longitudinal axis of the boat, the angles of incidence are maximum. 
     In the propulsion system shown in FIG. 7, two vertical driving shafts  11  are mounted on both sides of the boat  10 . They are rotated in opposite directions by an engine  41  through pulleys  42 ,  43 , a driving belt  44 , a shaft  45  and gear engagements  14 ,  15 . The engine  41  can be mounted in the hull of the boat  10 . 
     FIGS. 8 and 9 illustrate a propulsion system with a different design of the rotated planetary gear-boxes  16 . Four bevel mitre gears  46 ,  47 ,  48  and  49  which are engaged with each other, are mounted in the gear-box  16  on the radial shafts  18 ,  19 ,  20  and  21 , respectively. Two planet bevel mitre gears  50 ,  51  are mounted on the radial shafts  18  and  19 , respectively, so that they are engaged with the sun bevel mitre gear  52  which is fixed on the axial support means  17 . Each of the radial shafts  18 ,  19 ,  20 ,  21  is rotatably mounted in two bearings. One bearing ( 22 ,  23 ,  24  or  25 ) is mounted in the wall of the gear-box  16  and another bearing is mounted in the central bearing support  53 . In operation, the rotation of the gear-box  16  is transmitted to the rotation of the blades  32 ,  33 ,  34 ,  35  by the planetary engagements of the gears  52 ,  50 ,  51  and by four engaged gears  46 ,  47 ,  48 ,  49 . 
     An alternative embodiment of the propulsion apparatus for a marine vessel  54  is illustrated in FIGS. 10,  11 . A horizontal hollow driving shaft, which consists of two parts  55  and  56  with a gear-box  57  fixed between them, is mounted in the housings  58  and  59  perpendicular to the longitudinal axis of the vessel  54 . The design of the planetary gear-box  57  is essentially similar to the designs of the gear-boxes  16  in the embodiments of the propulsion apparatus as shown in FIGS. 1-9. A support means  17  is fixed coaxially to the hollow driving shaft on both sides of the vessel  54 . Two sun bevel mitre gears  26  and  27  are mounted on the support means  17  and are engaged with the planet bevel mitre gears  28 ,  29  and  30 ,  31 , respectively. 
     In operation, the hollow driving shaft is rotated together with the gear-box  57  and the blades  32 ,  33 ,  34 ,  35  by an engine  60  through pulleys  61 ,  62  and a driving belt  63  (or any other type of drive) in the direction indicated by arrow G. Simultaneously, the blades are rotated with the same speed around the axes of radial shafts. As a result of such double rotation in the vertical plane, the blades work in a paddling manner with the maximum propulsion force being exerted astern when the blades are in a vertical downward position. If the blades  32 ,  33 ,  34 ,  35  are positioned with angles of incidence in the planes of rotation around the radial shafts, they work simultaneously as double screw propellers. 
     Referring now to FIGS. 12 and 13, a vertical takeoff and landing aircraft is schematically shown. A propulsion system includes two hollow driving shafts mounted on both sides of the fuselage  64  of the aircraft parallel to its longitudinal axis. Each of the driving shafts consists of two parts  67  and  68  which are mounted in the housings  65 ,  66  with planetary gear-boxes  69  between them. Two sun angle bevel gears  70 ,  71  are mounted on an axial support means  72  in each of the gear-boxes  69  and the planet bevel mitre gears  73 ,  74 ,  75 ,  76  are mounted on the radial shafts  77 ,  78 ,  79 ,  80 , respectively. The blades  81 ,  82 ,  83  and  84  are mounted on the ends of these radial shafts with variable angles of incidence so that when the blades  81  and  82  are oriented along the longitudinal axis of the aircraft, the blades  83  and  84  extend sidewards in horizontal directions from the aircraft. 
     In operation, the hollow driving shafts are rotated together with planetary gear-boxes  69  synchronously in opposite directions, indicated by arrows H and K, by the engines  85  and  86  through the gear engagements  87 ,  88 . The blades on each side of the fuselage  64  are working as “flapping wings”. As a result, a vertical propulsive force is exerted for lifting or sustaining the aircraft. The blades have airfoil cross-sections so that when the aircraft is moving ahead by any other type of propeller or jet engine (not shown), the blades in horizontal positions can be used as regular wings. 
     While this invention has been described with reference to the structures disclosed herein, they are merely chosen and described to illustrate the principle, applications, and practical use of the invention to thereby better enable others skilled in the art to utilize this invention. The preferred embodiments of the present invention illustrated in FIGS. 1-13 are not confined to the details as set forth and are not intended to be exhaustive or to limit the invention to the precise form disclosed. For example, the driving shafts can be rotatably mounted on the support means ( 17 ,  72 ), which can be simultaneously used for fixing the sun gears of the planetary engagements. The invention is intended to cover any modifications, which may be variously practiced within the scope of the following claims or their legal equivalents, rather than by examples given.