US 3809005 A
A propulsion system for a vessel is described which includes an intake duct and an annular duct which together define a passage which provides two 180 DEG reversals of direction. The annular duct provides a passage of increasing mean diameter and continuously decreasing interior cross section. An impeller accelerates the water by imposing dynamic and centrifugal forces thereon. Stator blades are provided to cause discharge of the water in a direction essentially straight to the rear of the boat.
Claims available in
Description (OCR text may contain errors)
United States Patent Rodler, Jr.
3,809,005 May 7, 1974 PROPULSION SYSTEM Waldo E. Rodler, Jr., 1488 Cherry Garden Ln., San Jose, Calif. 95125 Filed: July 20, 1972 Appl. No.: 273,503
US. Cl ..115/12 R, 60/221,114/151, 239/265.19, 115/12 A Int. Cl B6 3h 25/ 46 Field of Search 115/35, 70, l1, 12, 14; 114/151; 239/265.l9, 11, 12; 60/221, 222
References Cited UNITED STATES PATENTS 10/1965 Gongwer 114/151 4/1971 Wislicenus et a1 115/12 1l/l966 Gongwer 115/12 Smith 115/12 Primary Examiner-Trygve M. Blix Assistant ExaminerDonald W. Underwood Attorney, Agent, or FirmFitch, Even, Tabin &
Luedeka 57] ABSTRACT A propulsion system for a vessel is described which includes an intake duct and an annular duct which together define a passage which provides two 180 reversals of direction. The annular duct provides a passage of increasing mean diameter and continuously decreasing interior cross section. An impeller accelerates the water by imposing dynamic and centrifugal forces thereon. Stator blades are provided to cause discharge of the water in a direction essentially straight to the rear of the boat.
7 Claims, 5 Drawing Figures :aLaosLoos PATENTEUIIAY 7 I974 SHEET 1 BF 2 PROPULSION SYSTEM This invention relates generally to propulsion systems and, more particularly, to an improved propulsion system for a vessel.
Many so-called water-jet propulsion systems have been proposed for use in propelling vessels. Such systems have an advantage over the more traditional rotary propeller type propulsion systems in that they are capable of operating in shallow water, are safer to nearby swimmers or water skiers, and are capable of producing higher speeds and quicker acceleration. The so-called water-jet propulsion systems are especially suited to small craft, although larger vessels may also employ such propulsion systems.
Notwithstanding the foregoing advantages, prior art water-jet propulsion systems suffer from certain significant drawbacks. Efficient matching of the torque and speed requirements of the system to its driving engine is often difficult. Frequently, such systems suffer from a thrust angle imbalance which requires a massive construction to offset the non-axial component of the thrust. Often, the size of the prior art water-jet propulsion systems is excessive, occupying space which is needed for other purposes in the vessel. Also, internal losses in many of the prior art systems are considerable, resulting in an inherent lower efficiency.
Accordingly, it is an object of the present invention to provide an improved propulsion system for a vessel.
Another object of the invention is to provide an improved vessel propulsion system of the so-called waterjet type.
It is another object of the invention to provide a water-jet propulsion system for a vessel which is of relatively compact physical size.
A further object of the invention is to provide a water-jet propulsion system for a vessel which is low in cost and highly efficient in operation.
Other objects of the invention will become apparent to those skilled in the art from the following description, taken in connection with the accompanying drawings wherein:
FIG. 1 is a side elevational view illustrating a preferred embodiment of the invention;
FIG. 2 is a rear view of the embodiment shown in FIG. 1;
FIG. 3 is an enlarged full section side view of the embodiment shown in FIG. 1;
FIG. 4 is a partial sectional view of a portion of FIG. 3, illustrating operation of thrust reversing means; and
FIG. 5 is an elevational view of a further embodiment of the invention.
Very generally, the propulsion system of the invention comprises means defining an intake duct 11 having an intake orifice 12 adapted to be positioned for receiving water. The intake duct is shaped to direct water flowing into it through a change in direction of substantially 180. Means l4 define an annular duct 15 contiguous with the intake duct at the end of the intake duct opposite the intake orifice. The annular duct has a continuously increasing mean diameter and a continuously decreasing interior cross section, and is shaped to direct water flowing therethrough through a change in direction of substantially 180. Moving impeller blades within the annular duct accelerate the water by means of dynamic and centrifugal forces, and stator blading in the annular duct is designed to neutralize circumferential swirl in the water produced by the moving impeller blades. The water is thus discharged in a direction essentially straight to the rear of the vessel.
Referring now more particularly to the drawings, FIGS. l-4 show the preferred embodiment of the invention as comprising a so-called inboard/outdrive propulsion system attached to the rear of the vessel 13, the vessel being shown in section in FIG. 3. The vessel includes a transom 23 and a keel 25. An opening 27 is provided in the lower part of the transom, and a propulsion system mount 29 is fitted within the opening 27 and is secured to the transom by suitable means, not shown, at a flange 33 of the mount. 7
The mount 29 supports a shaft housing 35 in which a rotary drive shaft 37 is provided. Suitable means, not shown, are provided at one end of the drive shaft 37 for coupling to a suitable driving engine, not shown. The other end of the drive shaft 37 carries a yoke 41 which is joined to another yoke 43 by a universal coupling 45. The mount 29 also supports a bilge pump hose 46, shown only in FIG. 3. A discharge hose 48 is attached to the mount 29 to communicate with the bilge pump hose 46.
The yoke 43 is supported on one end of an impeller shaft 47 which, in turn, is mounted in a housing 49 in suitable bearings 51 and 52 therein. A bellows 55 is provided for sealing the universal coupling, and extends between the shaft housing 35 and the bearing housing 49.
The means 10 defining the intake duct 11 is, in the illustrated embodiment, a horn which defines the intake orifice 12 at one end. The periphery of the orifice 12 lies in a plane which is inclined slightly from the horizontal at an angle of about 30 and which therefore orients the orifice 12 toward the direction in which the vessel 13 is to travel. Accordingly, as the vessel moves through the water, water enters the intake duct 11 at a corresponding velocity.
A cavitation plate 57 is provided toward the lower end of the horn 10. Also, a pair of interior baffles 58 and 59 are supported transversely in the duct 11 to eliminate excess swirling and turbulence. The intake horn 10 is supported by means of suitable bolts 61, one of which is shown in FIG. 3, from the duct means 14.
A steering mount bracket 65 is secured to the flange 33 on a shim plate 66. A steering post 67 is mounted in a bearing 67a in the bracket 65 and supports a steering yoke 68. The steering yoke 68 has a boss 68a which receives the post 67. The boss 68a is secured to the post 67 by a pin 69. The upper part of the yoke 68 has a boss 68b axially aligned with the boss 68a. A post 70 is held in the boss 68b by a pin 70a axially aligned with the post 67. Thus, the yoke pivots on the posts 67 and 70.
The means 14 which defines the annular duct 15 is provided with a pair of lugs 71 (see FIG. 1) which extend parallel with each other toward the vessel and which are pivotally mounted by means not shown to opposite sides of the yoke 68. Thus, the means 14 may pivot upwardly on the lugs 71. A tilt control rod 72 is secured to the outer end of a tilt bracket 73 by means of a pivot coupling 74. The tilt control rod 72 extends through a suitable connection 75 to the interior of the vessel 13 and is operable to move the tilt bracket 73.
Hence, the entire portion of the propelling system aft of the vessel 13 may pivot on the lugs 71 to an upwardly tilted position. This places the periphery of the inlet orifice 12 in a horizontal plane above the lower level or keel 25 of the vessel. This is the non-operating or stored position of the propulsion system. In the down position shown in FIGS. 1 to 3, a stop pin 76 engages a stop bracket 76a to support the assembly. Other holes 80 are provided to place the pin 76 to adjust the angle of tilt.
As may be seen in FIG. 3, a steering control link 77 extends from a suitable coupler 79 in the transom of the vessel. The steering post 70 is mounted in. the coupler 79 in alignment with the steering post 67 and with the centerof the connection between the yoke 43 and the universal coupling 45. The sides of the yoke 68 pass on opposite sides of the bellows 5S and link to the steering mount bracket 65. Accordingly, the entire assembly aft of the posts 67 and 70 may be turned with the yoke 68 by the link 77 to steer the vessel.
A diffuser cone 82 is positioned at the end of the intake duct 11 opposite the intake orifice 12. The cone 82 comprises part of the means 14 which define the annular duct 15. A plurality of rotor or impeller blades 84 (see FIG. 3) are mounted in an impeller 89 having an inner cone extension 85 and an outer ring 85a, and extend inwardly across the annular duct. The impeller 89 is supported on a spindle 86 extending axially of the shaft 47 and joined thereto.
A plurality of stator blades 87 are also provided. The stator blades are mounted in the annular duct 15 on the means 14 which define the annular duct 15. The annular duct 15 is contiguous with the inlet duct 11 in the region of the diffuser cone 82, that is, the end of the inlet duct opposite the intake orifice 12. The duct 15,
. defined by the one end of the horn 10, the diffuser cone 82 and the impeller 89, has a continuously increasing mean diameter and a continuously decreasing interior cross section. The duct is shaped to direct water flowing in it through a change in direction of substantially l80, and from a single flowing stream to one which is annular in shape. By changing the direction of flow of the water by 180, the discharge of the water is toward the rear of the vessel, thereby causing propulsion of the vessel in a forward direction. By increasing the diameter of the annulus, centrifugal force is employed to accelerate the water. By decreasing the cross section of the annular duct, a nozzle effect is created to maximize thrust.
The stator blades 87 are arranged to eliminate the swirl of circumferential component of velocity in the water produced by rotation of the impeller blades 84. Alternatively, the stator may be ahead of the rotor in which case the stator is designed to provide a circum ferential component of velocity which will approximately match and offset the rotational or circumferential component of velocity imparted to the water as a result of the rotation of the impeller 89. In either case, the stator blades neutralize the effect of the rotary impeller, and the resultant velocity of the water is substantially straight to the rear of the vessel. This provides improved thrust and avoids any unbalanced situation in the steering of the vessel.
It may be seen in FIG. 3 that a zone exists where the water being discharged from the annular orifice of the impeller 89 is directed at the intake horn 10. The intake horn may be streamlined to minimize losses as a result of its position. As a further provision, a cooling water pickup intake (not shown) may be placed to receive the water discharged from the annular orifice of the impeller 89 and which would normally strike the intake horn 10. This water may then be conveyed through a suitable cooling water pickup conduit, not shown, to the engine, not shown. Accordingly, the need for an engine cooling pump is eliminated and losses as a result of the interference of the intake horn 10 are minimized.
In order to reverse the direction of thrust provided by the propulsion system of the invention, a thrust reverser is provided comprising an annular final segment 10] (see FIG. 3) of the duct means 14. As illustrated, the annular segment 101 has a shield 103 of curved cross section extending outwardly. The annular segment is mounted on a plurality of slide pins 104 distributed circumferentially about the duct means 14 so that it may slide axially to the position illustrated in FIG. 4. In the latter position, the shield 103 provides a reversal of thrust for moving the vessel toward the rear. Each of the slide pins 104 extends between the main portion of the duct means 14 at a boss 105 therefor to a flange 106 on the horn 10. A slide collar 107 is slidably mounted on each pin 104 and extends from the annular segment 101.
Control over the thrust reverser segment 101 is provided by a linkage arrangement which may be seen in FIG. 1. The segment is connected by a pair of brackets 108 to a linkage comprised of arms 109 and 110. Suitable means, not shown, inside the vessel 13 may be operated to cause the linkage 109-110 to move the segment 101 to reverse thrust position.
Although the invention has been shown in connection with an outboard/inboard configuration, it is clearly adaptable to either an outboard configuration or an inboard configuration.
An outboard configuration is shown in FIG. 5. The intake duct of the embodiment of FIG. 5 is shown at configured in a manner similar to that of the intake duct of the previous embodiment. The internal construction of the apparatus of FIG. 5 is identical to that of the previously discussed embodiment insofar as the intake duct, the impeller, and the stator blading are concerned. Power for the impeller is derived from a suitable engine 131 and the power train includes a suitable drive shaft and bevel gear arrangement, not shown, in a housing 132, to transmit torque to the impeller. An engine mount 133 is provided for mounting the outboard propulsion unit on the transom 137 of the vessel 139.
The propulsion system of the invention provides a number of significant advantages. The system protrudes a minimal distance below the bottom of the vessel to which it is attached, thereby permitting operation of the vessel in extremely shallow water. No exposed propeller blades exist below the vessel where they are subject to damage by rocks, logs, etc., and where they can cause possible injury to swimmers or water skiers nearby. Moreover, because any blading is fully shrouded within the ducts, improved efficiency results because of a lessening of propeller tip losses. The inherent torque and speed requirements of the propulsion system of the invention provide a much better match to the normal performance characteristics of a typical commercially available outboard engine than prior art systems, thus improving overall performance. Because there is no steering imbalance, improved handling ability for the vessel is provided, and full reverse thrust may be obtained at any speed, permitting fast emergency stopping of the boat. Because of the folded configuration (ie two 180 turns), the overall size of the propulsion system is substantially less than that of prior art devices, facilitating transportation and storage. The propulsion system of the invention is extremely low in cost and is relatively easily manufactured.
It may therefore be seen that the invention provides an improved propulsion system for a vessel which is high in efficiency, low in cost, smaller in size, and superior in operation and handling characteristics to prior art devices.
Various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description and accompanying drawings. Such modifications are intended to fall within the scope of the appended claims.
What is claimed is:
1. A propulsion system for a vessel, comprising, means defining an intake duct having an intake orifice positioned for receiving water, said means defining said intake duct comprising curved flow directing walls curved continuously to provide a 180 turn for the water to direct the water flowing in an initial direction to a direction opposite to the initial direction, means defining an annular duct contiguous with said intake duct at the end of said intake duct opposite said intake orifice, said means defining said annular duct having walls of continuously increasing mean diameter and a continuously decreasing interior cross section, and curved continuously to provide a second 180 turn to direct water flowing therethrough through a continuous change in direction of substantially 180 such that the water is flowing in a direction approximate that of its initial direction at said intake orifice and substantially opposite to the direction at which it entered said annular duct, a plurality of stator blades arranged within said annular duct, and a rotary impeller having a plurality of impeller blades arranged within said annular duct, said impeller blades and said stator blades being arranged at angles to impart a substantially axial directional velocity to the flowing water leaving said annular duct when said impeller is rotated.
2. A propulsion system according to claim 1 wherein said impeller is upstream in said annular duct from said stator bladesand, when rotated, imparts a directional component of velocity to the flowing water which is circumferential with respect to said annular duct, and wherein said stator blades are mounted in fixed relation to said annular duct at angles such as to substantially remove said circumferential component of velocity.
3. A propulsion system according to claim 1 wherein said means defining said annular duct include a diffusion cone having its apex toward the end of said intake duct opposite said intake orifice.
4. A propulsion system according to claim 1 including a thrust reverser and means for selectively positioning said thrust reverser at the outlet of said annular duct to produce a reversal in the flow of water issuing from said annular duct.
5. A propulsion system according to claim 1 including means for pivotally supporting said system, and means for controlling the pivoted position of said system with respect to the vessel to steer the vessel.
6. A propulsion system according to claim 5 including drive means for rotating said impeller, and a universal joint coupling said drive means to said impeller.
7. A propulsion system for a vessel, comprising, means defining an intake duct having an intake orifice positioned for receiving water, said intake duct being shaped to direct water flowing therethrough through a continuous change in direction of substantially such that the water is flowing in a direction opposite to its initial direction, a diffusion cone having its apex toward the end of said intake duct opposite said intake orifice, an impeller defining at least part of an annular duct contiguous with said intake duct adjacent said diffusion cone, said annular duct having a continuously increasing mean diameter and a continuously decreasing interior cross section, said annular duct being shaped to direct water flowing therethrough through a continuous change in direction of substantially 180 such that the water is flowing in a direction approximate that of its initial direction at said intake orifice, a plurality of impeller blades mounted in fixed relation to said impeller within said annular duct, drive means for rotating said impeller, and a plurality of stator blades arranged within said annular duct at an angle to remove the circumferential component of velocity in the flowing water which is produced by rotation of said impeller and thus impart a substantially axial directional veloc-