US3019662A - Gyroscopic control mechanism - Google Patents

Description

Feb. 6, 1962 E. H. GAHN 3,019,662

GYROSCOPIC CONTROL MECHANISM Filed April 14, 1955 3,619,662 GYRQSCOPEC (IONTROL MECHANISM Edwin H. Gahn, Normandy, Mo., assignor, by mesne assignments, to Systron-Donner Corporation, Concord, Califi, a corporation of California Filed Apr. 14, 1955, Ser. No. 501,240 12 Claims. (Cl. 745.7)

The present invention relates generally to gyroscopic controls, and more particularly to a novel self-powered gyroscopic control mechanism of unusually small size and exceptionally high sensitivity.

Although the principle of the gyroscopic control has long been known, the increasing demand for automatically controlled, self-propelled units has brought forth a great deal of effort directed to improvements inboth the directional accuracy and the sensitivity of response in gyroscopic units adapted for directional control. As an example, a gyroscopic intelligence unit for directional control of a guided missile must have the attributes of accuracy and sensitivity above mentioned in the highest degree, and must at the same time be truly miniature in both size and weight. Additionally, the rotating assembly must have the lowest power requirement consistent with the necessary speed of rotation to provide the desired accuracy of response, and the torque requirements to maintain a constant rotor speed should not vary appreciably upon operative disturbance from the principal axis of the unit.

It is an object of the present invention, therefore, to provide a novel self-powered gyroscopic control mechanism which avoids the use of gimbal frames for support of the rotating element.

It is another object of the invention to provide a novel gyroscopic control mechanism which incorporates a squirrel cage rotor disposed externally of a fixed stator, the rotor being at all times concentric with the spin axis of the gyroscopic mechanism.

It is another object of the invention to provide a novel gyroscopic control mechanism incorporating an induction motor in which the stator takes the general form of a symmetrical segment of a sphere, and in which the rotor is formed so as to be complementary therewith.

It is another object of the invention to provide a novel gyroscopic control mechanism in which the rotor has universal pivotal movement relative to the stator without consequent deterioration of the driving torque.

The foregoing, along with additional obiects and advantages, Will be apparent from the following description taken in conjunction with theaccompanying drawing, in which:

FIGURE 1 is a side elevational view of a gyroscopic control mechanism conforming to the present invention, certain cooperative structure being illustrated in broken outline;

' FIGURE 2 is a vertical sectional view taken generally on the longitudinal axis of the mechanism;

FIGURE 3 is a vertical sectional view taken generally along the line 3-3 in FIGURE 1;

IGURE 4- is a vertical sectional view taken generally along the line 4-4 in FIGURE 1;

FIGURE 5 is a vertical sectional view taken generally along the line 5-5 in FIGURE 1 and drawn to reduced scale; and

FIGURE 6 is a side elevation of a removed support.

Referring to the drawing more particularly through the use of reference characters, the numeral 10 desigatcnt intense Patented Feb. 6, 19%32 nates generally a gyroscopic control mechanism constructed in accordance with the teachings of the present invention. This mechanism 10 comprises a fixed stator assembly 12, a movable rotor assembly 14, and a shiftable caging assembly 16.

Directing attention first to the stator assembly 12, a support 18 having a sleeve-like barrel 20 provided with a radial mounting flange 22has mounted therein a double-row ball bearing assembly 24. This ball hearing assembly 24 is of the self-aligning type, and its outer race is maintained in fixed position relative to the barrel 20 by means of an annular retainer 26 threadedly received in the barrel 20 as clearly illustrated in FIGURE 2. A stack of laminations 28, provided with conventional slots 30 for receiving windings 32, is mounted on the outside of the barrel 20, being positioned by means of aflange 34 integral with the support 18 so that the longitudinal center of the laminated stack 28 is in alignment with the longitudinal center of the bearing assembly 24. The stack 28 and the support 18 are secured together by well-known means, such as cycle welding, for example. The periphery of the laminated stack 23 is formed, preferably with a high degree of accuracy, to a spherical surface, the spherical center being at the pivotal center of the self-aligning bearing assembly 24.

The assembled stator assembly 12 is, as illustrated in the drawing, adapted to be mounted against a wall or bulkhead 36 by means of screws 38 which threadedly engage the mounting flange 22.

Turning attention now to the rotor assembly 14, an elongated shaft 40 is mounted near one of its ends within the inner race of the self-aligning bearing assembly 24, this mounted relationship being maintained by a shaft nut 42 engaging the extreme end of the shaft 40. The nut 42 is provided with an end recess 44 disposed axially beyond the adjacent end of the shaft 44 as clearly illustrated in FIGURE 2. It may be noted at this time that the recess 44 accommodates the free end of a rod-like direction stop 46 mounted in the bulkhead 36 and secured by a setscrew 48. The significance of this arrangement will be explained more fully hereinafter.

With one of its ends mounted as above described, the shaft 4% extends through the annular retainer 26 and beyond the end of the support 18, where it mounts a Wheel St). The Wheel 50 has a hub portion 52 which fits a slightly enlarged portion 54 of the shaft 4ft, a radial disc-like portion 56 which is secured by means of screws 58 to a radial flange ea formed integral with the shaft 4t), and a rim portion 62 which is axially extended so as to encompass substantially the whole of the stator assembly 12.

The inside of the rim portion 62 of the wheel 54 is formed to receive twin squirrel cages 64, each comprising a stack of laminations 66 flanked by end rings 68 electrically interconnected by conducting bars 70 in the usual manner. The annular squirrel cages 64 are disposed in side-by-side abutment and have their inward surfaces formed to a spherical shape so as to be complementary with the external spherical surface presented by the laminated stack 28 aforementioned. The squirrel cages 64 are positioned axially Within the wheel 5% by means of setscrews 72 and are then secured in place by well known means, such as cycle welding. The open end of the wheel 50 comprising that part of the rim portion 62 which extends beyond the squirrel cages 64 is internally threaded so as to receive a balance ring 74 which may be adjusted axially to achieve a desired balance of the complete rotor assembly 14.

The relationship between the squirrel cages 64 and the laminated stack 28' is clearly such that the former can rotate freely around the longitudinal axis of the bearing assembly 24 and can also swivel or pivot in all directions about the pivot center of the bearing 24. There is, of course, the usual uniform air gap between the stator laminations 28 and the squirrel cage laminations 66, and the illustrated greater thickness of the laminated stack 28 as compared with the twin squirrel cages 64 insures that the magnetic fiux between these parts remains substantially constant regardless of changes in relative positions therebetween. The direction stop 46 limits the swiveling movement of the rotor assembly to a permissible maximum.

Returning to the shaft 40 an integral extension 76 extends beyond the flange 60 and is provided with a disclike flange 73 for transmitting certain intelligence derived from operation of the mechanism 10, as will be more fully explained hereinafter. Finally, the shaft 46 terminates in a knob-like journal portion 80 having a tapered end 82. As best illustrated in FIGURE 1, the journal portion *80 is adapted to fit within a ball cage 84 forming part of a ball bearing 86. The caging assembly 16, however, is movably mounted in a bulkhead shown in broken lines as 88, and it will be understood that under certain circumstances, the bearing 86 may be withdrawn from the position of FIGURE 1 to that illustrated in FlGURE 2, so as to be completely disengaged from the shaft 40.

Operation As previously noted, the gyroscopic control mechanism of the present invention is particularly adapted for use in applications where small size is mandatory, without sacrifice in either sensitivity of response or accuracy of transmitted intelligence. A typical application would be in the control of automatically guided missiles.

In such an application, the mechanism is installed within a casing, such as 90, shown in broken lines in FIGURES 1 and 2, provided with bulkhead assemblies 36 and 88 for mounting the parts as illustrated. Initial operation of the mechanism 1.0 is with the caging assembly 16 in the position of FIGURE 1, the windings 32 of the stator assembly 12 being energized from an appropriate source of electricity (not shown) carried within the missile. The spin axis of the caged shaft 40' is, of course, disposed at least parallel with, and preferably concentric with, the longitudinal axis of the missile, illustrated in the present example by the casing 90.

Preferably, the rotor assembly 14 is permitted to attain a stabilized rotational velocity before the missile is launched, and the shaft 40 is retained in caged condition until after the initial acceleration of the launching operation. After the missile has been launched, however, the caging assembly 16 is automatically withdrawn so that the shaft 41) is free to pivot about the pivotal center of the self-aligning ball bearing assembly 24, or more accurately, the missile itself is enabled to gyrate relative to the gyroscopically maintained axial alignment of the rotor shaft 40.

It is obvious, of course, that any deviation of the missile from its preestablished straight course will be reflected in relative displacement of the axis of the missile relative to the axis of the rotor shaft 4i). Thus, it becomes necessary only to detect the direction of displacement in order to provide appropriate counteracting procedures. A system of pick-off devices (not shown) arranged circumferentially around the periphery of the disc-like flange 78 in position to be influenced by very slight relative movements of the latter will detect the desired intelligence.

Clearly, there has been described a gyroscopic control mechanism which fulfills the objects and advantages sought therefor.

It is to be understood that the foregoing description and the accompanying drawing have been given only by way of illustration and example. It is further to be un derstood that changes in the form of the elements, rearrangement of parts, or the substitution of equivalent elements, all of which will be apparent to those skilled in the art, are contemplated as being within the scope of the invention, which is limited only by the claims which follow.

What is claimed is:

l. A gyroscope control mechanism comprising, in combination, electromagnetic prime mover means including a first stator assembly and movable rotor assembly, and a self-aligning ball bearing assembly having a central pivot point in fixed relation to said stator assembly, said rotor assembly being rotatably retained and supported by said bearing assembly for universal pivotal movement about said central pivot point, the stator assembly including a stack of laminations in encircling relation to the ball bearing assembly, and electrical conducting means associated therewith for establishing a magnetic field, the rotor assembly including squirrel cage inducting means in encircling relation to the stator laminations.

2. The mechanism of claim 1 wherein the stack of stator laminations is formed to a convex spherical surface and the squirrel cage means in the rotor is provided with a concave spherical surface, the centers of said convex and concave spherical surfaces being substantially coincident with the central pivot point defined by the aforesaid ball bearing assembly.

3. A gyroscopic control mechanism, comprising, in combination, a SUPPOIT, an electromagnetic stator assembly alfixed to the support, a frictionless self-aligning ball bearing assembly mounted in the support and defining a pivotal center therein, and wheel means including a squirrel cage rotor assembly supported in said bearing assembly for both continuous rotation and limited universal pivotal movement about a substantially horizontal axis.

4. The mechanism of claim 3 wherein said stator assembly, said rotor assembly, and said bearing assembly have coincident center points of symmetry.

5. A gyroscopic control mechanism comprising, in combination, a tubular support, an annular electromagnetic stator assembly disposed externally of said support, a swivel bearing disposed internally of said support, and an elongated rotor shaft having sole support adjacent one end in said bearing for unrestrained combined rotation and swiveling movement, said shaft extending longitudinally beyond said tubular support, a bowl-shaped wheel having a hub portion secured to said shaft beyond said support and a rim portion which encompasses said stator assembly, and an annular induction assembly affixed within said rim portion for prime moving cooperation with said electromagnetic stator assembly.

6. The mechanism of claim 5 with the addition of a balancing ring adjustably disposed in the free end of said rim portion for acheving a desired condition of balance in the rotating assembly.

7. The mechanism of claim 6 wherein the induction assembly and the stator assembly are concentric, one being provided with a convex spherical surface and the other being provided with a concave spherical surface.

8. The mechanism of claim 7 wherein the stator assembly is of greater axial length than the induction assembly.

9. The mechanism of claim 5 wherein the end of the shaft remote from the aforementioned bearing is formed for removable supported engagement in a caging assembly.

10. The mechanism of claim 5 wherein the shaft is provided with a circular radial flange remote from the bearing supported end.

1-1. In a gyroscopic control mechanism, a rotor assembly comprising an elongated shaft, means adjacent one end of said shaft for mounting it in the movable race of a self-aligning frictionless bearing, means at the opposite end of said shaft for restrained engagement with a caging device, means on the shaft adjacent said opposite end thereof for influencing a pick-01f device, a wheel including a hub portion afiixed to a central portion of said shaft, said wheel further including an axially extended rim portion encircling the electromagnetic induction means including a laminated assembly formed to a concave spherical shape symmetrically related to the pivot center of that portion of said shaft to be disposed in said movable race aforementioned, and means adjustably mounted at the free end of said rim portion for balancing the rotor assembly about said pivot center.

12. In a gyroscopic control mechanism, a hollow cantilever support, a self-aligning substantially frictionless bearing mounted within said hollow support, an electromagnetic stator assembly mounted on said support, said stator assembly including a core structure formed to a symmetric convex spherical shape concentric with the pivot center of said bearing, and an electromagnetic rotor assembly mounted in said bearing for both rotational and pivotal movement about said pivot center, said rotor assembly including a core structure formed to a symmetrical concave spherical shape concentric With said pivot center.

References Cited in the file of this patent UNITED STATES PATENTS 791,983 Leblanc June 6, 1905 1,495,769 Brewerton May 27, 1924 1,802,108 Chessin Apr, 21, 1931 1,959,309 Smith May 15, 1934 1,984,874 Gillmor Dec. 18, 1934 2,093,503 Wittkuhns Sept. 21, 1937 2,138,531 Wise et al. Nov. 29, 1938 2,384,761 Mehan Sept. 11, 1945 2,423,270 Summers July 1, 1947 2,452,335 Stoner Oct. 26, 1948 2,581,965 Miller Jan. 8, 1952 2,708,369 Dixson May 17, 1955 FOREIGN PATENTS 1,082,038 France June 16, 1954 150,452 Great Britain Sept. 9, 1920 554,594 Great Britain July 12, 1943

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