US2880616A

US2880616A - Compensated gyroscope

Info

Publication number: US2880616A
Authority: US
Publication date: 1959-04-07
Anticipated expiration: 1976-04-07

Description

April 7, 1959 E. F. AUMULLER COMPENSATED GYROSCOPE 3 Sheets-Sheet 1 Filed March 17, 1954 April 7, 1959 E. F. AUMULLER 2,830,616

COMPENSATED GYROSCOPE Filed March 17, 1954 I 5 Sheets-Sheet 2 2 u a Z iNVENTOR [p/MvWMu/e United States Patefl 2,880,616 COMPENSATED GYROSCOPE Edward F. Aumuller, Lynbrook, N. assignor to Sperry Rand Corporation, a corporation of Delaware Application March 17, 1954, Serial No. 416,853

6 Claims. (Cl. 745.7)

This invention relates to an improved construction for gyroscopes, and especially for the rotor bearing frames and the rotors thereof. In the usual construction, the outer case which encloses the rotor also provides the spaced bearings in which the rotor shaft is journalled. It is, therefore, necessary to make the casing of sufficiently heavy and rigid material to keep the rotor bearings in their proper spaced position and in alignment. Much trouble has also been experienced in prior designs by unequal expansion of the rotor and its shaft with respect to the enclosing casing, causing binding and unbalance about one or more axes of the gyroscope.

According to my invention, I use the outer casing only as an enclosure for the rotor but support the rotor bearings from a web extending through the middle of a divided or split rotor constituting'dual rotors. Such web also supports on opposite sides thereof a common stator or two like stators for the two rotors. The rotors are journalled within sleeves or hubs extending in both directions from the web and lying within and supporting the stators, and are tied together by an axially extending strut, preferably placed under tension, thus forming a common shaft for the rotors. The two rotors and their stators are entirely symmetrical on both sides of the web so that no disturbance of the gyro balance will be caused due to thermal expansion. Furthermore, in my design, the heat from the stators is effectively dissipated to the exterior of the case which is connected to the web so as to conduct the heat from the same to the two exterior shells or cups. Since the shells do not support any bearings, they may be made very thin and light, and are preferably of hemispherical shape so as to be readily removable and also easily hermetically sealed to the circumferential flanges forming the rim on the web or wheel. The case may, therefore, be either evacuated or floated in a liquid, or both.

Referring to the drawings illustrating two forms my invention may assume,

Fig. 1 is a plan or elevational view of a gyro constructed in accordance with my invention with the gimbal, one casing, and also one rotor partly cut away to show the interior construction. If Fig. 1 represents a gyro of the directional type it is an elevation, while if it represents a gyro vertical it is a plan view;

Fig. 2 is a transverse section taken on line 2-2 of Fig. 1;

Fig. 3 is an exploded sectional view showing the dual rotors and their enclosing cups and the central interior bearing frame which supports the two stators, and on which the rotors are journalled;

Fig. 4 is a sectional view similar to Fig. 2 showing a modified form of the invention; and

Fig. 5 is a transverse section taken on broken line 5-5 of Fig. 4.

From Fig. 3, it will be at once apparent that my main frame 1 which supports the rotor bearings 3-5 lies within instead of without the rotor or rotors 7 and 9 and their enclosing casing or shells 11 and 13, as is the usual practice. The shells 11 and 13 constitute correspondingly shaped members for enclosing the rotors that are fitted in oppositely disposed relation on the circumferential rim portion of the frame 1. Said bearing frame is shown as comprising a circumferential ring 15 or wheel having a central web or disc 17 and trunnions 19 and 21 forming a part of the bearings 23-23' between the gyroscope and the gimbal ring 25. The central web is provided with a hub or axially extending tube-like projections 27 which extend in both directions from the web and and within which are mounted the aforesaid rotor bearings 3 and 5. The gimbal ring 25 in turn is journalled on trunnions 26, 26' within a fixed support 55. If the gyro happened to be designed as having but a single degree of freedom in addition to the spin axis, it will be understood that the gimbal ring 25 will be omitted and the bearings 23--23' will be located directly in the fixed support.

Preferably, the rotor bearings are of the ball bearing type with the outer races held within the two ends of the hub against spacing sleeve 29 by locknuts 3131'. The inner races 33 are spaced by a second sleeve 35 through which extends a central tie rod or shaft 37 on each end to which the hubs 45 of each of dual rotors 7 and 9 are secured. Said rod closely fits the hubs 45 but is preferably of less diameter than the interior of the sleeve 35, and

' when the device is assembled, the rod is locked to each hub by the engagement of cross pins 39 in the forked end of each hub. After assembling, the nut 41 is screwed onto the-lower end of the shaft 37 and tightened, as shown in Fig. 2, preferably placing the shaft 37 under tension to make a rigid rotor shaftand to lessen thermal expansion.

Each rotor is preferably of generally hemispherical shape exteriorly and each is hollowed out interiorly to form facing cavity 40 with the interior perimeter of each cavity mounting the squirrel cage construction 43 of the polyphase induction motorwhich spins each rotor. The two

stators

42 and 42" are shown as mounted on the two ends of thehubor sleeve 27 on each side of the web 17. The lead in wires 47 to the windings 49 of the stators are shown as 'passing through a central aperture in one of the trunnions 19, the web being provided with a cutaway portion 51 to give access to the wires.

The entire dual rotor is enclosed in a thin shell of sheet material, such as steel, formed in two sections or cups 11 and 13. Each section tightly fits and is adapted to be hermetically sealed to the upper and lower flanges 57-57 formed in the rim or ring 15, and it will be observed that these shells or cups do not support any bearings nor have any wires passing therethrough so that the shells may be readily removed for inspection of the rotors and the spinning motors.

A study of the construction above described will show that it possesses many advantages over the standard construction of gyro rotors now employed and constitutes a high precision temperature compensated gyroscope of a simple, rugged construction and with completely symmetrical design. Thus, the rotor bearing frame 17 and its hub 27 may be made in one piece so that the rotor bearings are maintained in the original alignment at all times. The unbalancing effect of expansion of the parts due to thermal expansion is largely prevented and in any event completely compensated by the fact that twin rotors and twin stators are employed on each side of the gyro axis assuring equal expansion on both sides of the trunnion axis 19, 21. This permits the employment of a different metal in the rotor structure than in the casing or rotor frame thus permitting a very heavy metal to be employed in the rotors without disturbing the balance of the gyroscope due to temperature changes.

In my construction also, the heat generated in the .53 stator windings is readily dissipated to the exterior ring 15 and shells by the solid web or disc 17 which extends between and beyond the two rotors where it is joined to the outer shells. My construction also may be readily disassembled for inspection without disturbing the rotor hearings or Wiring.

A somewhat modified form of my invention is shown in Fig. 4. According to this modification, the twin rotor construction and an interior rotor bearing frame 17' are retained, but the twin rotors 7' and 9' and shells or cups 11 and 13' are shown as bowl shaped instead of hemispherical as in the previous form. In this form also, the central web 17 extends only partially between the rotors and a single stator frame 59 is employed, the exterior of which is rigidly secured within the web 17' around its inner periphery. In this form, the stator frame 59 provides the hub 61 which houses and supports the spaced rotor bearings 3' and A modified form of ball bearing is also shown in Figs. 4 and 5. Such bearings may have common inner and common outer races in the form of long sleeves 63 and 65 near each end of which the ball races are formed and balls mounted. The outer sleeve 65 is shown as held in place within the hub by locknuts 67, while the inner sleeve forms a spacer between the two inner hubs 68 and 68' of the two rotors. While each rotor has its own squirrel cage 43', the stator may be common to both and have common windings 69. The two rotors may again be tied together by a central tie rod 37' as before. This construction possesses substantially all the advantages of the construction of Figs. 1 to 3.

Since many changes could be made in the above construction and many apparently widely different embodiments of this invention could bemade without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A gyroscope comprising closely positioned twin, hemispherical rotors, each having facing cavities, a rotor bearing frame resembling a wheel having a central web positioned between the rotors, a hub extending within both cavities, each rotor having a hollow interior hub journalled within the hub of said frame, said web terminating at its periphery in a circumferential rim, journals on said rim for pivotally supporting said gyroscope, and a pair of substantially hemispherical sheet metal cups adapted to be secured to each side of said rim.

2. A gyroscope comprising a circular plate having a rim, a central hub projecting on at least one side thereof, a sleeve journalled within said hub on spaced antifriction bearings, an electrical stator supported on said hub, a cup-like rotor normally overlying said stator and having a shaft normally projecting through said sleeve, means for securing said rotor and shaft to said sleeve, and an outer cup-like case secured to said rim around its periphery, whereby said case may be removed without disturbing the rotor bearings or stator.

3. A gyroscope as claimed in claim 2, wherein said rotor shaft detachably clamps said rotor to said sleeve, whereby the rotor may also be removed without disturbing the rotor bearings or stator.

4. A gyroscope comprising closely positioned twin, cupped rotors having facing cavities, a rotor bearing frame resembling a disc wheel having an outer rim, a central web positioned between the rotors, each rotor having a hub extending within its cavity, means for tying said hubs together to form a common shaft for the rotors, spaced bearings for said shaft, means for supporting said bearin-gs by said central web, and a pair of end cups of sheet material adapted to enclose the rotors and to closely fit the rim of said disc wheel.

5. A gyroscope comprising closely positioned twin, cupped rotors having facing cavities and a rotor bearing frame resembling a wheel having an outer rim, said frame including a central web positioned between the rotors and a hollow hub extending within each cavity, said rotors also having hollow interior hubs extending toward each other and spaced bearings journalling said hubs within the hub of said frame, and a pair of end cups of sheet material adapted to enclose the rotors andto fit the rim of said wheel.

6. A gyroscope comprising a rotor bearing frame resembling a wheel having a circumferential rim portion, a central web portion and a hub portion, a pair of coaxial rotors supported on the hub portion of said frame with the web portion in equidistant and central relation thereto, and a casing for enclosing the spaced rotors formed of a pair ofcorrespondingly shaped members fitted in oppositely disposed relation on the circumferential rim portion of said frame.

References Cited in the file of this patent UNITED STATES PATENTS 2,345,915 Carlson Apr. 4, 1944 2,382,967 Beach Aug. 21, 1945 2,731,836 Wendt Jan. 24, 1956 FOREIGN PATENTS 2,695 Great Britain July 19, 1906 of 1906 623,943 Great Britain May 25, 1949