US3612443A

US3612443A - Thrust-producing gyro system

Info

Publication number: US3612443A
Authority: US
Inventors: William W Stripling
Original assignee: US Department of Army
Current assignee: US Department of Army
Priority date: 1969-07-03
Filing date: 1969-07-03
Publication date: 1971-10-12
Anticipated expiration: 1988-10-12

Abstract

A thrust-producing gyro system for attitude control of missiles. The gyro system guides a missile along a path determined by the attitude of a space-oriented rotating wheel without using intermediate amplifiers. The gyro system includes a hot gas source that supplies gas to a housing enclosing a plenum chamber. The chamber has a pair of tubular members radially disposed for providing gas flow to the inner surface of a high-momentum wheel for rotation thereof. Additional tubular members extend radially from the plenum chamber to terminate adjacent the interior annular surface of the high-momentum wheel and provide gas flow which is exhausted from the tubes at ports in the missile skin adjacent the end of each tube. The output gases spin the wheel at a high momentum. The rotating wheel covers a portion of each tube outlet so that relative motion between the missile and wheel varies the gas escaping from each tube, increasing the gas escaping from one port while decreasing the gas escaping from an opposing port, and thereby provides a restoring force to the missile.

Description

United States Patent William W. Stripling [72] Inventor Huntsville, Ala. [21] App]. No. 838,814 [22] Filed July 3, 1969 [45] Patented Oct. 12, 1971 [73] Assignee The United States of America as represented by the Secretary of the Army [54] THRUST-PRODUCING GYRO SYSTEM 6 Claims, 3 Drawing Figs.

[52] US. Cl 244/3.2, 137/38, 74/5 [51] Int. Cl ..B64c 15/04, F42b15/02,F42b 15/18 [50] Field of Search 244/ 3.2

[5 6] References Cited UNITED STATES PATENTS 3,304,029 2/ l 967 Ludtke 244/ 3.2 0 3,476,129 1 1/1969 l-lalstenberg 24413.2 0 X Primary Examiner-Benjamin A. Borchelt Assistant Examiner-Thomas H. Webb Attorneys-Harry M. Saragovitz, Edward J. Kelly, Herbert Bet] and Harold W. Hilton ABSTRACT: A thrust-producing gyro system for attitude control of missiles. The gyro system guides a missile along a path determined by the attitude of a space-oriented rotating wheel without using intermediate amplifiers. The gyro system in cludes a hot gas source that supplies gas to a housing enclosing a plenum chamber. The chamber has a pair of tubular members radially disposed for providing gas flow to the inner surface of a high-momentum wheel for rotation thereof. Additional tubular members extend radially from the plenum chamber to terminate adjacent the interior annular surface of the high-momentum wheel and provide gas flow which is exhausted from the tubes at ports in the missile skin adjacent the end of each tube. The output gases spin the wheel at a high momentum. The rotating wheel covers a portion of each tube outlet so that relative motion between the missile and wheel varies the gas escaping from each tube, increasing the gas escaping from one port while decreasing the gas escaping from an opposing port, and thereby provides a restoring force to the missile.

FI IGHT AXIS PATENTED um I 2 mm -fl-Li AXIS FIG. 3

SUMMARY OF THE INVENTION The apparatus of the present invention is a device for providing attitude control of missiles or projectiles and does not require additionalamplifier stages to pick upand amplify deviation of the projectile from the desired flight path. The thrust-producing gyro system utilizes a free rotor to provide two degrees of freedom and thereby provide pitch and yaw control of the projectile. The momentum of the rotor, rotating wheel, is high enough to minimize the effect of torques associated with the flow of controlling gases. The gyro is brought up to speed and is uncaged at launch of the projectile and maintains the projectile on a course normal to the plane of the spinning wheel. A gas generator supplies hot exhaust gas to a housing containing a plenum chamber. The plenum chamber has a pair of tubular members disposed radially therefrom for providing gas flow therethrough to the inner surface of the high-momentum wheel to develop and maintain the rotation thereof. A plurality of tubular passageway forming control members extend radially from the plenum chamber and terminate adjacent the inner surface of the missile, with the distal or terminating end thereof being partially covered by an edge of the rotating wheel. Control jets in the form of exhaust ports are provided in the terminating end of each tube to exhaust gas through the outer surface of the missile or projectile. The

. rotating wheel, which covers a portion of each of the control jets so that relative motion in the projectile and wheel increases and decreases gas flow, varies the gas escaping to the prq'ectile surface and thereby provides a restoring force thereto. With the projectile on course, gas escaping from the control jets is equal in all jets and the forces therefrom on the missile are balanced, providing no restoring force. The output exhaust gases provide directional control between the wheel and the missile on a plane perpendicular to the missile flight aXlS.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a plan view of a preferred embodiment of the invention.

FIG. 2 is a view along line 2-2 of the embodiment of FIG. 1.

FIG. 3 is a view of a missile incorporating the invention therein.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings wherein like numerals represent like parts in all figures, there is disclosed a preferred embodiment of the invention in FIGS. 1 and 2. A thrustproducing gyro system comprises a hot-gas generator 12 that is connected to a housing 14 enclosing a plenum chamber. Gas generator 12 is disposed for directing gases into the plenum chamber through a tubular member 13. A plurality of tubular passageway forming

control members

24, 26, 28 and 30 are secured to housing 14 in communication with the plenum chamber.

Members

24, 26, 28, and 30 extend radially outwardly from housing 14 and terminate adjacent th e interior annular surface 15 of a high-momentum wheel that is rotatably supported on the missile support structure as described hereinbelow.

Tubular members

24, 26, 28 and 30 are provided with

exhaust portions

240, 26a, 28a and 300 on the distal ends thereof. These exhaust portions or ports are positioned in normal relation to the missile longitudinal axis and are partially covered by the interior surface of the wheel. Each of

members

24, 26, 28 and 30 are spaced 90 from adjacent members on a plane perpendicular to the missile flight axis. Member 24 is located

adjacent members

26 and 30 and is diametrically opposite member 28. A series of indentations 22 or buckets are disposed around the inside circumference 15 of wheel 20. Wheel 20 is rotatably mounted on a spherical hearing 40 having a shaft 42 attached thereto. For example, wheel 20 may rotate on ball hearings or air bearings (not shown). Shaft 42, generator 12 and plenum chamber housing 14 are fixed within a missile or other vehicle and are coaxial with the missile flight axis.

A pair of

spin nozzles

32 and 34 is provided for directing jets of gas against indentations 22 on wheel 20 to impart spin thereto and to maintain spin thereof.

Spin nozzles

32 and 34 comprise a pair of tubular passageway forming members hav-.

ing one end secured to housing 14 in communication with the plenum chamber. The distal ends of

spin nozzles

32 and 34 include end portions or ports 32a and 34a, respectively, which are disposed inside wheel 20, in normal relation to the missile axis to direct gases against indentations 22 on surface 15.

The thrust-producing gyro system must be brought up to speed while in a caged position. This is done before the missile 44 (FIG. 3) is launched. Caging, in general, is along the rocket axis. Wheel 20 is limited by shaft 42, allowing from 5 l0 of motion to either side of the shaft, for example. Missilel144 is committed to a particular trajectory path as determined by the situation involved and gas generator 12 is ignited. Generator 12 may be ignited by any convenient means such as a squib rupture type disk or a gas piston (not shown) driven from the main missile generator. When generator 12 is ignited, hot gases therefrom are introduced into plenum chamber housing 14. The pressure building up in chamber 14 escapes through the exhaust and spin ports. Gas from spin ports 32a and 34a bring wheel 20 up to the desired r.p.m., which may vary depending on the range and bearing design employed therein. While the rotating wheel is brought up to speed and thereafter, the hot gases escaping from

exhaust ports

24a, 26a, 28a and 300 are balanced. At this initial reference or null position, the edge 23 of spinning wheel 20, covers a portion of the four exhaust or control jets. Because of the equal gas flow in all exhaust ports, the wheel spin axis coincides with the missile flight axis, maintaining the plane of the spinning wheel perpendicular to the flight axis.

The thrust-producing gyro 10, as noted in FIG. 3, is mounted to the structure of missile 14 in front of the center of gravity CG. Spinning wheel 20 has an outer diameter that is slightly less than the inner diameter of the missile skin. Openings 46 in the skin of missile 44 are aligned with

exhaust ports

24a, 26a, 28a and 300, thus allowing the escaping control gases to exhaust from the missile at a specific place.

Launching of the missile uncages the gyro wheel 20. Prior to launch the missile is maintained in a relatively fixed position which prevents movement of the missile support structure with respect to spinning wheel 20, caging the wheel. Supported by bearing 40 and shaft 42, wheel 20 is activated by gas escaping from the spin and output ports, gas from the spin ports imparting wheel rotation and gas from the output ports stabilizing the wheel position before launch. Hence, the unlaunched missile cages the spinning wheel, and launching of the missile uncages the wheel by allowing movement between the support structure and the wheel. Any tendency of missile 44 to deviate from an axis normal to the plane of wheel 20 after launching of the missile causes a restoring force to be applied to the missile. For example, deviation of the fore end of the missile in the general direction of port 24a causes a restoring force from port 24a to be applied. As missile 44 drifts oficourse, generator 12, chamber 14 and bearing 40 drift proportionally since they are fixed to the missile structure. Wheel 20 is free to move with respect to hearing 40 and therefore remains unmoved from the caged position of revolution as bearing 40 drifts with the missile. This relative movement of bearing 40 and chamber 14 causes port 24a to become more uncovered and port 28a to be more covered by spinning wheel 20. The additional gas pressure being ejected out port 24a couples with the reduced gas pressure of port 28a to force the nose of missile 44 toward the axis of spinning wheel 20, thereby returning the missile to its original path or course. During the restoring action the gas escaping from ports 26a and 300 will vary but will not provide a restoring effect when drift is directly toward

port

24a or 280.

Obviously, missile drift in the direction of a particular quadrant formed by the ports will bring about restoring action from all ports. For example, fore end drift of missile 44 into the quadrant formed by

ports

24a and 26a will result in wheel 20 covering more of the exhaust ports 28a and 30a and simultaneously uncovering more of

ports

24a and 26a. A restoring force will then be provided by each control jet and will be proportional to the amount of drift toward the particular jet. An increase in gas flow will be provided by ports 24a and 260 with a respective decrease in gas flow from diametrically oppmed control or exhaust ports 28a and 30a returning the missile to the flight path.

In the event that gas escaping from ports 46 on the missile surface increases turbulence or provides intermittent control due to airflow around the nose of the missile, or for other reasons, the gyro system can be mounted in the rear of the missile. The thrust-producing gyro system would be rotated 180 so that generator 12 is toward the front of missile 44 and wheel 20 is toward the rear. Drift of the nose of missile 44 in the direction of control port 244 causes port 240 to move under the edge 23 of wheel 20 thus reducing the gas escaping therefrom and increasing the gas output of port 28a, thereby restoring the missile to the flight path.

The exhaust ports may employ linear or nonlinear gate valves. The logarithmic shaped valve 27 on port 26a of FIG. 1 provides a linear gas flow with respect to the position thereovcr of wheel 20. All exhaust ports employ the same type of valve opening to insure balanced outputs therefrom.

Wheel 20 is capable of obtaining velocities above 10,000 rpm, depending on the bearing design. The edge 23 of wheel 20 that passes over the four exhaust ports is tapered to minimize torques that are transferred to the wheel by aeroballistic lift forces perpendicular to the gas flow. The tapered edge 23 prevents a large vacuum area and ofisets the tendency of gas flow to pull the edge of wheel 20 over jet opening 27, thereby providing more positive control over the missile flight path.

It is obvious from the foregoing disclosure that a more elaborate system may be employed using the identical principles. For example, six exhaust ports may be used and spaced at 60 from adjacent ports, and additional spin jets may be used. More than one thrust producing gyro system may be used to provide a more rapid response by adjusting both fore and aft ends of the missile simultaneously. A system may employ eight exhaust ports with four balanced nonlinear ports and four balanced linear ports. Similarly three exhaust ports at 120 degree intervals may be employed to provide a more slowly responding but equally successful system. Various other combinations and modifications of the thrust-producing gyro system may be readily apparent to those skilled in the art.

lclaim:

l. A thrust-producing gyro for attitude control comprising: a hot gas generator, a plenum chamber having an input port connected to said generator and having a plurality of output ports for conveying gas therethrough, a high-momentum wheel mounted adjacent to said output ports for providing two degrees of freedom and disposed for rotation responsive to impingement thereon by gases from certain of said output ports, other of said output ports being adapted for differential closing and porting respectively, thereby guiding a projectile or moving vehicle along a predetermined path normal to the plane of the wheel and controlled by the attitude thereof, said other output ports include at least four exhaust or control jets for conveying gas therethrough at a uniform velocity to be exhausted therefrom to the outer surface of said projectile, an inner annular edge of said rotating wheel covers at least a portion of said control jets, and each of said control jets are equidistant from adjacent jets so that relative motion in the projectile and the wheel will decrease the flow in one or more jets while increasing the flo in the opposing jets to provide a restoring force to the projectile, and wherein the exhaust from said jets is on a plane perpendicular to the flight axis of said projectile.

2. A thrust-producing gyro as set forth in claim 1 wherein the outer edge of said rotating wheel that asses over the control ets is tapered to minimize the torques eing transferred to the wheel by lift forces perpendicular to the gas flow, the inner surface of said wheel includes a series of indentations therearound adjacent to one edge thereof, and wherein said output ports further include at least two spin jets that eject gas to said indentations to bring the wheel up to speed and to maintain the wheel speed.

3. A thrust-producing gyro as set forth in claim 2 and further comprising a spherical bearing, and wherein said generator, plenum chamber and spherical bearing are fixed with respect to said projectile, said rotating wheel is free to move on said spherical bearing, and said control jets have a logarithmic rate of change of port area or opening, shaped to provide a linear flow function as the wheel position varies thereover.

4. A thrust-producing gyro for attitude control comprising: a hot-gas generator, a plenum chamber having an input port connected to said generator and having a plurality of spin and output ports for conveying gas therethrough, a high-momentum wheel mounted adjacent to said output ports for providing two degrees of freedom and disposed for rotation responsive to impingement thereon by gases from said spin ports, said output ports being adapted for differential closing and porting respectively, thereby guiding a projectile or moving vehicle along a predetermined path normal to the plane of the wheel and controlled by the attitude thereof, said output ports comprise four tubular passageway forming control members extending radially outward from said chamber and having exhaust or control jets in the distal ends thereof, said exhaust jets are spaced apart on a plane perpendicular to the flight axis of said projectile and convey gas therethrough to be exhausted to the outer surface of said projectile, an inner edge of said rotating wheel covers at least a portion of said control jets so that relative motion in the projectile and the wheel will decrease the flow in one or more jets while increasing the flow in the opposing jets to provide a restoring force to the projectile, the inner surface of said wheel includes a series of indentations therearound adjacent to one edge thereof, said spin ports include two tubular passageway forming control members extending radially outward from said chamber and having spin nozzles or ports on the distal end thereof disposed adjacent the interior annular surface of said wheel to direct gases against said indentations to initiate and control the wheel spin rate.

5. A thrust-producing gyro as set forth in claim 4 and further comprising a spherical wheel support bearing, and wherein the edge of said wheel that passes over the control jets is tapered on the outer edge to minimize torques being transferred to the wheel by lift forces perpendicular to the gas flow, said rotating wheel is free to move on said spherical bearing, said gas flowing through said control jets provides pitch and yaw control to maintain the projectile on a course normal to the plane of the wheel, and said generator, plenum chamber and spherical bearing are fixed with respect to said projectile.

6. A thrust-producing gyro as set forth in claim 5 wherein the control jets have a logarithmic rate of change of port area or opening, shaped to provide a linear flow function as the wheel position varies thereover.

Claims

1. A thrust-producing gyro for attitude control comprising: a hot-gas generator, a plenum chamber having an input port connected to said generator and having a plurality of output ports for conveying gas therethrough, a high-momentum wheel mounted adjacent to said output ports for providing two degrees of freedom and disposed for rotation responsive to impingement thereon by gases from certain of said output ports, other of said output ports being adapted for differential closing and porting respectively, thereby guiding a projectile or moving vehicle along a predetermined path normal to the plane of the wheel and controlled by the attitude thereof, said other output ports include at least four exhaust or control jets for conveying gas therethrough at a uniform velocity to be exhausted therefrom to the outer surface of said projectile, an inner annular edge of said rotating wheel covers at least a portion of said control jets, and each of said control jets are equidistant from adjacent jets so that relative motion in the projectile and the wheel will decrease the flow in one or more jets while increasing the flow in the opposing jets to provide a restoring force to the projectile, and wherein the exhaust from said jets is on a plane perpendicular to the flight axis of said projectile.

2. A thrust-producing gyro as set forth in claim 1 wherein the outer edge of said rotating wheel that passes over the control jets is tapered to minimize the torques being transferred to the wheel by lift forces perpendicular to the gas flow, the inner surface of said wheel includes a series of indentations therearound adjacent to one edge thereof, and wherein said output ports further include at least two spin jets that eject gas to said indentations to bring the wheel up to speed and to maintain the wheel speed.

4. A thrust-producing gyro for attitude control comprising: a hot-gas generator, a plenum chamber having an input port connected to said generator and having a plurality of spin and output ports for conveying gas therethrough, a high-momentum wheel mounted adjacent to said output ports for providing two degrees of freedom and disposed for rotation responsive to impingement thereon by gases from said spin ports, said output ports being adapted for differential closing and porting respectively, thereby guiding a projectile or moving vehicle along a predetermined path normal to the plane of the wheel and controlled by the attitude thereof, said output ports comprise four tubular passageway forming control members extending radially outward froM said chamber and having exhaust or control jets in the distal ends thereof, said exhaust jets are spaced 90* apart on a plane perpendicular to the flight axis of said projectile and convey gas therethrough to be exhausted to the outer surface of said projectile, an inner edge of said rotating wheel covers at least a portion of said control jets so that relative motion in the projectile and the wheel will decrease the flow in one or more jets while increasing the flow in the opposing jets to provide a restoring force to the projectile, the inner surface of said wheel includes a series of indentations therearound adjacent to one edge thereof, said spin ports include two tubular passageway forming control members extending radially outward from said chamber and having spin nozzles or ports on the distal end thereof disposed adjacent the interior annular surface of said wheel to direct gases against said indentations to initiate and control the wheel spin rate.