STABILIZER SYSTEMS FOR WATER-BORNE VESSELS
United States Patent 3643617
A stabilizer system for a ship having one or more hollow closed cylinders or fins projecting from the ship's hull into the water stream. Each cylinder or fin is provided with apertures through which water under pressure, supplied by a pump via valves, is directed to produce a variable boundary layer flow of water giving positive or negative lift on the or each cylinder or fin. The valves are operated by a hydraulic actuator in accordance with signals from a gyroscopic sensing mechanism so that the lift produced on each cylinder or fin opposes pitching, rolling and/or yawing motion of the ship.
US Patent References:
JET CIRCULATION CONTROL HYDROFOIL
Yuan - October 1969 - 3472192
Rotor control
Yuan - February 1960 - 2925129
Roll-stabilizing oscillating fin installation on ships
Allan - May 1951 - 2550752
JET CIRCULATION CONTROL HYDROFOIL
Yuan - October 1969 - 3472192
Rotor control
Yuan - February 1960 - 2925129
Roll-stabilizing oscillating fin installation on ships
Allan - May 1951 - 2550752
Application Number:
05/013599
Publication Date:
02/22/1972
Filing Date:
02/24/1970
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
415/914, 114/277
International Classes:
B63B39/06; B63B39/00; B63B39/06
Field of Search:
114/66.5H,126 416/1 244/42CC
Primary Examiner:
Blix, Trygve M.
Claims:
What I claim is
1. A stabilizer system for a water-borne vessel comprising at least one member projecting into the water which is divided internally into halves by a longitudinal partition substantially parallel to the direction of motion of the vessel, means for providing the member with a boundary layer flow of water, vessel attitude-sensing means, and valve means controlled by said sensing means for varying said boundary layer flow, said halves of the member being symmetrical and each half having at least one aperture for the substantially tangential discharge of water.
2. A stabilizer system according to claim 1, wherein each aperture is rearwardly directed.
3. A stabilizer system for a water-borne vessel comprising at least one member which projects into the water and is divided internally into separate upper and lower compartments by a longitudinal partition, means for providing the member with a boundary layer flow of water via said compartments, vessel attitude-sensing means, and valve means controlled by said sensing means and associated with said compartments for varying said boundary layer flow.
4. A stabilizer system according to claim 3, wherein the compartments are symmetrical and each compartment has at least one aperture for the substantially tangential discharge of water.
5. A stabilizer system according to claim 4, wherein each said aperture is rearwardly directed.
6. A stabilizer system according to claim 3, wherein said valve means comprise two valves each adapted to control the flow of water to one compartment and so connected that when one valve is open the other valve is closed.
7. A stabilizer system according to claim 3, wherein said member is retractable within the hull of the vessel.
8. A stabilizer system according to claim 3, wherein said member is of circular cross section.
9. A stabilizer system according to claim 3, wherein said member is mounted at an angle to the horizontal.
10. A stabilizer system for a water-borne vessel comprising at least one member projecting into the water, means for providing the member with a boundary layer flow of water via its interior, at least one rearwardly directed substantially tangential aperture in the member, for the discharge of water under pressure from the member, on each side of a plane bisecting the member and substantially parallel to the direction of travel of the vessel, the same number of apertures being arranged symmetrically on each side of said plane and each aperture being selectively and individually supplied with water under pressure, vessel attitude-sensing means, and valve means for controlling said interior flow of water, said valve means being controlled by said sensing means and thereby associated with said apertures for varying said boundary layer flow.
11. A stabilizer system according to claim 10, wherein the member is retractable.
12. A stabilizer system according to claim 10, wherein the member is of circular cross section.
13. A stabilizer system according to claim 10, wherein the member is mounted at an angle to the horizontal.
14. A stabilizer system for a water-borne vessel comprising a hollow stabilizer member adapted to project from the hull of the vessel into the water, means separating the interior of said member into upper and lower compartments, means providing rearwardly directed water discharge slots in said member, at least one slot for each compartment, means including valve means for selectively introducing water into one or the other of said compartments for discharge through said slots, and vessel attitude-sensing means operatively connected to control said valve means, said slots being so constructed and arranged as to modify boundary layer flow of water at said member to produce a variable lift force at said member.
15. The stabilizer system defined in claim 14, wherein said member is cylindrical with its axis normal to the vessel and the respective slots discharge water substantially tangentially upwardly and downwardly with respect to said member.
16. The stabilizer system defined in claim 14, wherein the surface of said member is curved adjacent the discharge ends of said slots and said slots are oppositely inclined relative to the direction of movement of said vessel.
1. A stabilizer system for a water-borne vessel comprising at least one member projecting into the water which is divided internally into halves by a longitudinal partition substantially parallel to the direction of motion of the vessel, means for providing the member with a boundary layer flow of water, vessel attitude-sensing means, and valve means controlled by said sensing means for varying said boundary layer flow, said halves of the member being symmetrical and each half having at least one aperture for the substantially tangential discharge of water.
2. A stabilizer system according to claim 1, wherein each aperture is rearwardly directed.
3. A stabilizer system for a water-borne vessel comprising at least one member which projects into the water and is divided internally into separate upper and lower compartments by a longitudinal partition, means for providing the member with a boundary layer flow of water via said compartments, vessel attitude-sensing means, and valve means controlled by said sensing means and associated with said compartments for varying said boundary layer flow.
4. A stabilizer system according to claim 3, wherein the compartments are symmetrical and each compartment has at least one aperture for the substantially tangential discharge of water.
5. A stabilizer system according to claim 4, wherein each said aperture is rearwardly directed.
6. A stabilizer system according to claim 3, wherein said valve means comprise two valves each adapted to control the flow of water to one compartment and so connected that when one valve is open the other valve is closed.
7. A stabilizer system according to claim 3, wherein said member is retractable within the hull of the vessel.
8. A stabilizer system according to claim 3, wherein said member is of circular cross section.
9. A stabilizer system according to claim 3, wherein said member is mounted at an angle to the horizontal.
10. A stabilizer system for a water-borne vessel comprising at least one member projecting into the water, means for providing the member with a boundary layer flow of water via its interior, at least one rearwardly directed substantially tangential aperture in the member, for the discharge of water under pressure from the member, on each side of a plane bisecting the member and substantially parallel to the direction of travel of the vessel, the same number of apertures being arranged symmetrically on each side of said plane and each aperture being selectively and individually supplied with water under pressure, vessel attitude-sensing means, and valve means for controlling said interior flow of water, said valve means being controlled by said sensing means and thereby associated with said apertures for varying said boundary layer flow.
11. A stabilizer system according to claim 10, wherein the member is retractable.
12. A stabilizer system according to claim 10, wherein the member is of circular cross section.
13. A stabilizer system according to claim 10, wherein the member is mounted at an angle to the horizontal.
14. A stabilizer system for a water-borne vessel comprising a hollow stabilizer member adapted to project from the hull of the vessel into the water, means separating the interior of said member into upper and lower compartments, means providing rearwardly directed water discharge slots in said member, at least one slot for each compartment, means including valve means for selectively introducing water into one or the other of said compartments for discharge through said slots, and vessel attitude-sensing means operatively connected to control said valve means, said slots being so constructed and arranged as to modify boundary layer flow of water at said member to produce a variable lift force at said member.
15. The stabilizer system defined in claim 14, wherein said member is cylindrical with its axis normal to the vessel and the respective slots discharge water substantially tangentially upwardly and downwardly with respect to said member.
16. The stabilizer system defined in claim 14, wherein the surface of said member is curved adjacent the discharge ends of said slots and said slots are oppositely inclined relative to the direction of movement of said vessel.
Description:
BACKGROUND OF INVENTION
The invention relates to a stabilizer system for a water-borne vessel.
SUMMARY OF THE INVENTION
According to the invention, a stabilizer system for a water-borne vessel comprises at least one member projecting into the water and provided with a variable boundary layer flow of water, the flow of water being controlled by valve means which are actuated in accordance with signals from vessel attitude-sensing means to produce a variable lift force on the or each member.
DESCRIPTION OF THE INVENTION
The invention will now be described, by way of example only, with reference to the accompanying drawings of which:
FIG. 1 is a plan view of a stabilizer member projecting from the hull of a ship;
FIG. 2 is a cross section on the line 2--2 in FIG. 1;
FIG. 3 is a diagrammatic view of automatic control gear for the member,
FIG. 4 is a sectional elevation of a mechanism for retracting the member into the ship's hull;
FIG. 5 is a sectional elevation of an alternative mechanism for retracting the member into the ship's hull; and
FIG. 6 is a plan view of the mechanism shown in FIG. 5.
Referring now to the drawings, a member comprising a hollow cylinder 11 with a closed outer end 12 projects from a ship's hull 13 into the water stream shown by the arrows 14 in FIG. 1, produced by the forward motion of the ship. The cylinder 11 is divided internally into halves 15 and 16 by a longitudinal portion 17 which is disposed parallel to the direction of motion of the ship, and water discharge slots 18, 19, 20 and 21 are formed in the cylinder 11, arranged symmetrically two on each side of the partition 17. Each slot is so shaped that water is discharged therefrom in a rearward direction as nearly tangential to the outer surface of the cylinder 11 as possible. When water under pressure is supplied to the half 15 of the cylinder 11 and discharged from the slots 18 and 19, the water stream is modified as shown by the arrows 14a in FIG. 2, and lift is induced on the cylinder 11 in the direction shown by the arrow 22 in said figure. Alternatively, by supplying water under pressure to the half 16 of the cylinder 11 and discharging it from the slots 20 and 21, lift is produced in the opposite direction.
Referring to FIG. 3, automatic control gear comprises roll sensing means in the form of a gyroscopic sensing mechanism 23 which transmits a signal to an electrical control unit 24. Said unit causes a hydraulic circuit 25 to actuate water control valves 26 and 27 in such a way that the valve 26 is open when the valve 27 is closed and vice versa. Water is drawn in through a forward facing intake 28 on the ship's hull 13, and delivered by a water pump 29 to the valves 26 and 27.
The hydraulic circuit 25 comprises an oil pump 30, an oil filter 31, a relief valve 32, a solenoid-operated directional valve 33, and a hydraulic actuator comprising a piston 34 slidable in a cylinder 35 which actuates the valves 26 and 27 via a linkage 36.
In operation, when the ship rolls in one direction, the gyroscopic sensing mechanism 23 transmits a signal to the control unit 24 which then energizes one solenoid of the directional valve 33. This directs oil under pressure from the pump 30 to one side of the piston 34 to move the linkage 36 and open, say, the valve 26 and close the valve 27, with the results already described. When the ship rolls in the other direction, the opposite effect is produced.
FIG. 4 shows an arrangement whereby the cylinder 11 can be retracted into the ship's hull 13 when not in operation. The cylinder 11 is connected to a coaxial double-acting hydraulic actuator 37 so as to be slidable in a tube 38 mounted in the hull 13. The water supplied from the valves 26 and 27 enters a block 39 secured to the tube 38 and is directed through telescopic tubes 40 and 41 to the respective halves 15 and 16 of the cylinder 11.
Referring to the alternative retraction mechanism shown in FIGS. 5 and 6, the cylinder 11 is provided near its inner end with hollow trunnions 42 and 43 mounted in bearings 44 and 45 in the ship's hull 13. A tiller arm 46 is attached to the trunnion 42, and a double-acting hydraulic actuator 47 rotates said arm. When the actuator 47 operates, rotation of the arm 46 causes the cylinder 11 to retract pivotally into a recess 48 in the ship's hull 13. The water supply from the valves 26 and 27 enters the hollow trunnions 42 and 43 via banjo units 49 and 50 and is directed therefrom to the respective halves 15 and 16 of the cylinder 11.
Roll stabilization can be achieved by the use of a single cylinder 11, but a larger stabilizing torque is obtained by providing two similar cylinders abeam of each other on opposite sides of the ship, so controlled by the same automatic control gear that when one is exerting a positive lift the other is exerting a negative lift, that is to say both cylinders are acting to turn the ship about its longitudinal axis in the same roll-opposing direction.
Combined pitch and roll stabilization can be achieved by providing two pairs of cylinders, the cylinders of each pair being abeam of each other and the pairs being spaced fore and aft from each other. All the cylinders are controlled by the same automatic control gear, the gyroscopic sensing mechanism 23 of which is capable of sensing both pitching and rolling motion of the ship's hull 13.
Pitch, roll and yaw stabilization can be achieved in a similar manner by providing two pairs of cylinders, the cylinders of each pair being abeam of each other, the pairs being spaced fore and aft from each other and each cylinder being mounted at an angle to the horizontal, preferably 45°, in the ship's hull 13. The cylinders are once again controlled by the same automatic control gear, the gyroscopic sensing mechanism 23 of which is capable of sensing pitching, rolling and yawing motion of the ship's hull 13. By mounting each cylinder at an angle to the horizontal the lift produced on each cylinder has not only a vertical component but also a horizontal component and this horizontal force can be used to counteract yaw.
In a modification, the or each projecting member is nonretractable.
In another modification, the or each projecting member is not necessarily of circular cross section but can be a static fin of symmetrical cross section which may be retractable but is particularly suitable in a nonretractable arrangement in order to minimize drag.
In a further modification, the hydraulic actuator 37 in FIG. 4 is replaced by a worm and screw drive.
In yet another modification, the partition 17 is dispensed with and the or each projecting member is provided with at east one rearwardly directed aperture, for the substantially tangential discharge of water, on each side of a plane bisecting the member ans substantially parallel to the direction of motion of the vessel, the same number of apertures being arranged symmetrically on each side of said plane and each aperture being selectively and individually supplied with water under pressure.
In yet a further modification, the or each member is a static fin which is symmetrical in cross section nd is provided with at least one rearwardly directed aperture for the discharge of water on each side of a plane bisecting the member, said plane being substantially parallel to the direction of motion of the vessel. Each member is divided internally in halves by a longitudinal partition parallel to said plane or alternatively each aperture is selectively and individually supplied with water under pressure.
In still another modification, the boundary layer flow of water is varied by sucking in water from the exterior of the or each projecting member through selected portions of its periphery.
The magnitude of the lift produced by the or each projecting member can be varied by varying the speed of the pump 29 which delivers water under pressure to produce the boundary layer flow of water.
The invention relates to a stabilizer system for a water-borne vessel.
SUMMARY OF THE INVENTION
According to the invention, a stabilizer system for a water-borne vessel comprises at least one member projecting into the water and provided with a variable boundary layer flow of water, the flow of water being controlled by valve means which are actuated in accordance with signals from vessel attitude-sensing means to produce a variable lift force on the or each member.
DESCRIPTION OF THE INVENTION
The invention will now be described, by way of example only, with reference to the accompanying drawings of which:
FIG. 1 is a plan view of a stabilizer member projecting from the hull of a ship;
FIG. 2 is a cross section on the line 2--2 in FIG. 1;
FIG. 3 is a diagrammatic view of automatic control gear for the member,
FIG. 4 is a sectional elevation of a mechanism for retracting the member into the ship's hull;
FIG. 5 is a sectional elevation of an alternative mechanism for retracting the member into the ship's hull; and
FIG. 6 is a plan view of the mechanism shown in FIG. 5.
Referring now to the drawings, a member comprising a hollow cylinder 11 with a closed outer end 12 projects from a ship's hull 13 into the water stream shown by the arrows 14 in FIG. 1, produced by the forward motion of the ship. The cylinder 11 is divided internally into halves 15 and 16 by a longitudinal portion 17 which is disposed parallel to the direction of motion of the ship, and water discharge slots 18, 19, 20 and 21 are formed in the cylinder 11, arranged symmetrically two on each side of the partition 17. Each slot is so shaped that water is discharged therefrom in a rearward direction as nearly tangential to the outer surface of the cylinder 11 as possible. When water under pressure is supplied to the half 15 of the cylinder 11 and discharged from the slots 18 and 19, the water stream is modified as shown by the arrows 14a in FIG. 2, and lift is induced on the cylinder 11 in the direction shown by the arrow 22 in said figure. Alternatively, by supplying water under pressure to the half 16 of the cylinder 11 and discharging it from the slots 20 and 21, lift is produced in the opposite direction.
Referring to FIG. 3, automatic control gear comprises roll sensing means in the form of a gyroscopic sensing mechanism 23 which transmits a signal to an electrical control unit 24. Said unit causes a hydraulic circuit 25 to actuate water control valves 26 and 27 in such a way that the valve 26 is open when the valve 27 is closed and vice versa. Water is drawn in through a forward facing intake 28 on the ship's hull 13, and delivered by a water pump 29 to the valves 26 and 27.
The hydraulic circuit 25 comprises an oil pump 30, an oil filter 31, a relief valve 32, a solenoid-operated directional valve 33, and a hydraulic actuator comprising a piston 34 slidable in a cylinder 35 which actuates the valves 26 and 27 via a linkage 36.
In operation, when the ship rolls in one direction, the gyroscopic sensing mechanism 23 transmits a signal to the control unit 24 which then energizes one solenoid of the directional valve 33. This directs oil under pressure from the pump 30 to one side of the piston 34 to move the linkage 36 and open, say, the valve 26 and close the valve 27, with the results already described. When the ship rolls in the other direction, the opposite effect is produced.
FIG. 4 shows an arrangement whereby the cylinder 11 can be retracted into the ship's hull 13 when not in operation. The cylinder 11 is connected to a coaxial double-acting hydraulic actuator 37 so as to be slidable in a tube 38 mounted in the hull 13. The water supplied from the valves 26 and 27 enters a block 39 secured to the tube 38 and is directed through telescopic tubes 40 and 41 to the respective halves 15 and 16 of the cylinder 11.
Referring to the alternative retraction mechanism shown in FIGS. 5 and 6, the cylinder 11 is provided near its inner end with hollow trunnions 42 and 43 mounted in bearings 44 and 45 in the ship's hull 13. A tiller arm 46 is attached to the trunnion 42, and a double-acting hydraulic actuator 47 rotates said arm. When the actuator 47 operates, rotation of the arm 46 causes the cylinder 11 to retract pivotally into a recess 48 in the ship's hull 13. The water supply from the valves 26 and 27 enters the hollow trunnions 42 and 43 via banjo units 49 and 50 and is directed therefrom to the respective halves 15 and 16 of the cylinder 11.
Roll stabilization can be achieved by the use of a single cylinder 11, but a larger stabilizing torque is obtained by providing two similar cylinders abeam of each other on opposite sides of the ship, so controlled by the same automatic control gear that when one is exerting a positive lift the other is exerting a negative lift, that is to say both cylinders are acting to turn the ship about its longitudinal axis in the same roll-opposing direction.
Combined pitch and roll stabilization can be achieved by providing two pairs of cylinders, the cylinders of each pair being abeam of each other and the pairs being spaced fore and aft from each other. All the cylinders are controlled by the same automatic control gear, the gyroscopic sensing mechanism 23 of which is capable of sensing both pitching and rolling motion of the ship's hull 13.
Pitch, roll and yaw stabilization can be achieved in a similar manner by providing two pairs of cylinders, the cylinders of each pair being abeam of each other, the pairs being spaced fore and aft from each other and each cylinder being mounted at an angle to the horizontal, preferably 45°, in the ship's hull 13. The cylinders are once again controlled by the same automatic control gear, the gyroscopic sensing mechanism 23 of which is capable of sensing pitching, rolling and yawing motion of the ship's hull 13. By mounting each cylinder at an angle to the horizontal the lift produced on each cylinder has not only a vertical component but also a horizontal component and this horizontal force can be used to counteract yaw.
In a modification, the or each projecting member is nonretractable.
In another modification, the or each projecting member is not necessarily of circular cross section but can be a static fin of symmetrical cross section which may be retractable but is particularly suitable in a nonretractable arrangement in order to minimize drag.
In a further modification, the hydraulic actuator 37 in FIG. 4 is replaced by a worm and screw drive.
In yet another modification, the partition 17 is dispensed with and the or each projecting member is provided with at east one rearwardly directed aperture, for the substantially tangential discharge of water, on each side of a plane bisecting the member ans substantially parallel to the direction of motion of the vessel, the same number of apertures being arranged symmetrically on each side of said plane and each aperture being selectively and individually supplied with water under pressure.
In yet a further modification, the or each member is a static fin which is symmetrical in cross section nd is provided with at least one rearwardly directed aperture for the discharge of water on each side of a plane bisecting the member, said plane being substantially parallel to the direction of motion of the vessel. Each member is divided internally in halves by a longitudinal partition parallel to said plane or alternatively each aperture is selectively and individually supplied with water under pressure.
In still another modification, the boundary layer flow of water is varied by sucking in water from the exterior of the or each projecting member through selected portions of its periphery.
The magnitude of the lift produced by the or each projecting member can be varied by varying the speed of the pump 29 which delivers water under pressure to produce the boundary layer flow of water.