US2364810A

US2364810A - Speed governing means

Info

Publication number: US2364810A
Application number: US417047A
Authority: US
Inventors: Paul A Noxon
Original assignee: Bendix Aviation Corp
Current assignee: Bendix Aviation Corp
Priority date: 1941-10-29
Filing date: 1941-10-29
Publication date: 1944-12-12
Anticipated expiration: 1961-12-12

Description

SPEED GOVERNING MEANS Filed Oct. 29, 1941 4 Sheets-Sheet 1 gwue/wto n Dec. 12; 1944. P. A. NOXON v 2,364,810

SPEED GOVERNING MEANS Filed Oct. 29, 1941 4 Sheets-Shee t 2 :23 Fig.3.

Paul .l/Voxon'.

SPEED GOVERNING MEANS Filed Oct. 29, 1941 4 Sheets-Sheet 3 3mm uZ fl/Voxom P. A. NOXON 2,364,810

Dec. 12, 1944.

S PEED GOVERNING MEANS Filed Oct. 29, 1941 4 Sheeis-Sheet 4 Paul .19. NOXOIZ/ P. A. NOXON 2,364,810

' change in the supply line.

, however, that ed claims.

Patented Dec. 12,1944

srsnp GOVERNING MEANS Paul A. Noxon, Tenafly, N. 1.. assignorto Bendix Bendix, N. Ja a' corpora- Aviation Corporation tion of Delaware Application October 29, 1941, ,Serial No. 417,045

19 Claims.

The present invention relates generally to speed governing means and more particularly to means for governing the speed of rotation of air driven device's.

An object of the present invention is to provide novel means for maintaining substantially constant the speed of rotation of air driven. de-

vices, such as, for example,gyroscopic rotors. Another object of the invention is to provide a novel air driven rotor which will rotate at a l substantially constant speed.

A further object of the invention is'to provide novel speed governing means for maintaining substantially constant the speed of rotation of air driven gyroscopic rotorsnotwithstanding changes in operating conditions which ordinarily occur, such as, for example, changes in absolute pressure, variations in relative pressure in the supply line, changes'in bearing friction, etc.

Another object of the invention is to provide In the drawings, wherein like reference charactesr refer tolike parts, throughout the several views,

Figure 1 is a side elevation, partially in section which is taken substantially along line l-l of Figure 2, of a fluid pressure driven gyroscopic rotor embodying the invention:

Figure 2 ure 1; V Figure 3 is a sectional view taken substantially along line 3-3 of Figure 2;

Figure 4 is a side elevation view, similar to is a top plan view of the rotor 01' Fig- Figure 1, partially in section which is taken along line 4-4 of Figure 2;

Figure ,5 is a top elevation view, partially in section, of a fluid pressure driven gyroscopic rotor illustrating a second embodiment of the invention novel speed control means for gyroscopic rotors whereby during a sudden change in the pressure i of the driving fluid issuing from the'nozzle, normally directing fluid pressure to impinge upon the rotor, a proportional amount of the fluid v pressure is by-passed prior to reaching the nozzle so that the rotor speed is maintained substan-. tially constant notwithstanding the pressure A further object of the invention is to provide novel speeclcontrol means for maintaining substantially constant thespeed of rotation 'of a fluid pressure driven gyroscopic rotor comprising a pneumatic relay having means associated'with the fluid pressure directing nozzle for automati cally maintaining substantially constant the pressure .of the fluid issuing-from the nozzle notwithstanding vari'atlon' in the pressure in the supply line.

Another and still further object is to provide a novel and sensitive pneumatic 'relay or pressure equalizer which will automatically maintain substantially constant the pressure of fluid issuing at its output notwithstanding variation in pressure of the-,iluid at its input.

The above and further objects and novel features of the invention'will more fully appear from the following detailed description when the same is read in connection with the accompanying drawings. It is to be expressly understood, the drawings are for purposes of illustration only and are not intended as a deflnition. of thelimits or the invention,reierence for the latter purpose being-had to the append- Figure 6 is a side elevation view of the gyroscopic rotor of Figure 5;

Figure 7 isan end view of the gyroscopic rotor otFigure5;and,

Figure 8 is a sectional view taken substantialiy along line H of Figure 5.

Referring now to the drawings and more par- -ticularly to Figure'3 thereof, thereis. shown a gyroscopicrotor l0 having a hollow hub portion I2 provided with ball bearing races llior mount:

ing the rotor for rotation or spinning about a stationary shaft i4 carried by a gimbal frame or ring 15. The rotor is also provided with buckets or vanes It at its outer periphery whereby fluid under pressure is directed against the vanes in a conventional manner by way of a nozzle If! to cause spinning of the'rotor about shaft ll.

Nozzle I1 is mounted in any suitable manner upon a standard I8, carried by gimbal ring II.

having a passage is formed therein, as shown in Fig. l, which communicates with and supplies the nozzle I! with fluid under pressure from a suitable source, not shown, in a manner to presently appear;-

.Gimbal ring I} is provided with trunnions 20, Fig. 1, which mount the ringv i5 onla stationary support if the gyro is to be used as a rate of turn gyroscope or within a second gimbal .lla which is adapted for angular movement about an axis perpendicular to trunnions 20. Since the present invention can be used in any gyroscopic instrument, no specific application has been shown since all of them are well known in the art.

One of the trunnions 20 is provided with a a longitudinal passage 2| which communicates fluid under pressure from any suitable source, (not shown) to passage is of standard It and from disturbing the accuracy of the gyroscope.

The novel means of the present invention for overcoming the foregoing dimculty and maintaining the rotor speed substantially constant comprises, as better shown in Figure 3, an annular permanent magnetic member 22 which is embedded or otherwise suitably mounted within the rotor to form a part thereof and an annular flux return ring 23 which is keyed or otherwise secured about the hub portion of the rotor, an air gap being provided between the magnet and the return ring.

Shaft I4, as shown in Fig. 3, is provided with a longitudinal passage 24 which communicates with two transverse bores 25, 26 likewise formed in the shaft. Bores 25 and 26 define an air bleed for passage 25, as will likewise presently appear.

A second standard 21, shown in Fig. 4, is carried 'by gimbal ring I5 at ,a point substantially 90 away from the first standard I8 and has a longitudinal passage 28 therein which, at one end, communicates by way of a conduit 29, shown in Fig. 2, with passage I9 of standard I at a point adjacent the input of nozzle I1, better shown in Fig. 1, and at its other end communicates with channel 24 of shaft I4.

A valve or sleeve member '30 is rotatably mounted about shaft I4 and is provided with transverse ports 3|, 32 which,'under certain predetermined conditions register with transverse bores 25, 26 of shaft I4 to bleed fluid pressure to the atmosphere from age 24.

An eddy current dra cup 33 having an outer rim disposed within the air gap between annular magnet 22 and the return ring 23 is attached to one end of sleeve 30. Upon rotation of rotor I0 a torque is exerted uponthe drag cup 33 by virtue of eddy currents set up in the rim-of the dra cup, such torque being proportional to the rotor speed. The drag cup is caused to move angularly because of the eddy currents induced in its -45 rim and this movement is opposed by a hair spring 34 anchored at one end to sleeve 30 and at its other end. to a pin(,35 fastened to standard 21. Spring 34 is designed so that its restoring a torque is proportional to its deflection and thusthe drag cup 33 during rotor rotation will assume an angular position away from its rest position which will be a measure of the gyro speed.

In operation, during the starting period, sleeve ports 3|, 32 will be out of registry with bores 25,

I 20 of shaft I4 so that full line pressure is available at nozzle II for impingement upon rotor vanes I 8 to drive the rotor. As the rotor comes up to speed, a corresponding angular displacement of sleeve 30 about pshaft I4 is effected by reason of, the angular displacement of the drag cup 33 until ports 3|, 32 are brought into partial registry with bores 25, 26 whereby some of the fluid pressure is bledfrom' passage 24 of shaft I4 so that an equilibrium is established between rotor speed, nozzle pressure and sleeve displacement.

' In the event of a surge in the line pressures, the fluid 'pressure' issuing from nozzle 11 is increased causing any increase in the rotor speed. Such increase in rotor causes a further displacement of sleeve 30 by way of drag cup 33 againstthe action of spring 34 so that the ports 3|, 32 and 'bbres 2.5, 26 Will be in full n'egi'stry,

. bleeding fluid pressure from passage 24 thereby reducing nozzle pressure, Reduction in nozzle pressure results in reduced rotor speed and spring 34 drags sleeve 30 and drag cup 33 back to the equilibrium position. If less than normal pressure is available at the. nozzle, rotor speed de- 5 creases causing a complete closure of bores 25, 26 by sleeve 30 thereby building up full pressure at the nozzle.

The greater the characteristic of nozzle pressure can be made relative to sleeve displacement the less change will be required to compensate for a given change in operating condition.

, In order to provide a more sensitive speed control of th nature hereinabove described a second embodiment of the present invention proposes the use of a novel pneumatic relay as shown in Figures 5 to 8, inclusive.

Referring now. more particularly to Figures 5 to 8, inclusive, wherein parts corresponding to similar parts in Figures 1 to 4, inclusive, are

designated by the same reference characters plus I00, a rotor H0 is mounted by way of suitable ball bearing races H3 for rotation about a stav tionary shaft II i carried ,by a gimbal frame or ring H5. Rotor. H0 is further provided with vanes I I6 about its outer periphery whereby fluid pressure issuing from nozzle I II impinges thereend and with nozzle I II at its other end, the nozzle,

being suitably secured to and carried by box Isl as shown in Figure 6.

Fluid under pressure 'isintroduced into cylindrical member I40 by way of a port I52, Figure 5, formed therein and communicates with nozzle III by way of hollow box I4I.

Mounted within rotor II 0 is an annular per- 40 manent magnet I22 and an annular flux return ring I23, the magnet and return ring being spaced apart from each other so as to define an air gap therebetween. A drag cup I33, having its rim disposed within the air gap between magnet I22 and return ring I23, is secured to a sleeve I30 mounted for rotation about shaft llfl'against the one end to the sleeve and at its other end to gimbal IIB by way ofapin I35.

Sleeve I30 is provided with orifices or ports I3I, I32 which normally register with transverse bores I25, I26 drilled in shaft II4 to communicate with a longitudinal channel I24 also formed within shaft II4, better shown in Fig, 8. Channel I24 communicates at its extreme end with a passage I43, shown in Fig. 5, formedin a portion of gimbal H5 which, in turn, communicates with pne end of the cylindrical member I40, for a purpose to presently appear.

.Mounted for reciprocal movement within the cylindrical member no are two pistons m and I45 carried by a common rod I46 which comprise a throttlingmeans for the nozzle III. The open end of member I40 is provided with an adjustable abutment I41, the inner end ofwhich is en- I gaged by one end of a spring. I40, theother end of 'spring- I48 being in engagement with piston I45 .so as to normally maintain the latter together with piston I44, which isprovided with a vent I43,

in the extreme left position as shown in Figure 5. In this position "a bleed orifice I50,- formed in member I40, is closed by wayof piston mi so that substantiallyall of the fluid pressure entering action of a hair spring I34 which is anchored at zle I I1 while some of the fluid pressurepasses into" channel I24 of shaft II4 by way of vent I400! piston I44 and passage I 43.

In order to balance the system because of the added weight of members I40 and I, a balancing disc I 5I Figure 8, may be provided which surrounds shaft 4 and is fastened by way of suitable means such as screws or bolts I52 and a plate I53 to gimbal frame II5 as better shown inFigure 6. I

In operation, during the starting period, the drag cup I33 and sleeve 130 are so positioned that ports I3I, I32 of the sleeve are in registry, with bores I25, I26 whereby fluid pressure from member I40 passing through vent I49 of piston I44, passage I43 and channel I24 is -bled t6 the atmosphere, preventing a build up in pressure on the left side of piston I44. The only force on piston I44 atthis time is the pressure exerted by spring I40 holding it in its left hand position thereby keeping bleed orifice I50 closed by virtue of piston I45 thus allowing fluid pressure to discharge through nozzle I I1,

As rotor I I comes up to its normal speed, eddy in the nature of a spiral bi-metallic strip which currents are induced in drag cup I33, in the manner hereinbefore described, causing an angular partially opening bleed orifice I50 because .of the simultaneous movement of piston I45 with piston I44. The rotor IIO, therefore, cannot run faster than the speed at which equilibrium has been established.

The pneumatic relay is more sensitiveas a control for maintaining the rotor speed substantially constant. It also acts in the nature of a pres- 40 to spin said rotor, a valve comprising two relasure equalizer for the reason that with a given opening between ports I3l, I32 and bores I25, I26, a sudden increase or surge in line pressure will increase rotor speed whereby the drag cup I33 and sleeve I30 are further displaced to close 45 will move the free end of hair spring 34 or I34, in accordance with temperature changes. For a definition of the limits of the invention, reference will be had primarily to the appended claims.- Iclaim: v 1. In combination with a fluidpressure driven rotor, a nozzle for directing said fluid pressure to spin said rotor, means comprising a by-pass valve communicating with said nozzle for varying the fluid pressure supplied to said nozzle, magnetic field producing means carried by and r0- tatable withsaid rotor, and means comprising a resiliently constrained member operatively connected to said valve and inductively associated with and mounted for angular movement by said magnetic field producing means an amount pro portional to the speed of said rotor and responding to a predetermined speed of rotation of said rotor 'for operating said valve.

2. In combination with a fluid pressure driven rotor, a nozzle for directing said fluid pressure to spin said rotor, a valve comprising two relatively movable members, one of said members communicating with the fluid pressure supplied to said nozzle and the other of said members adapted to by-pass fluid pressure communicated to said first member, magnetic fleld producing means carried by and rotatable with said rotor, and

means connected with the other of said members inductively associated with and mounted for angular movement by said magnetic field producing means an amount proportional to the speed oi said rotor and responding to a predetermined speed of rotation of said rotor for producing relative movement between said members whereby the fluid pressure supplied to said'nozzle is varied.

registry between ports I a I, I32 and bores 1:5, m.

Such closure increases pressure on piston- 4 to move it further to the right together with piston I45 against spring I48 to completely open bleed orifice I50 and thus compensate for the increased rotor speed by by-passing fluid pressure from member I40 to the atmosphere through orifice I50. As soon as rotor speed decreases, spring I34 acts to return sleeve I30 and drag cup L33 to a position where ports l3i, I32 are brought into registry with bores I25, I20 to relieve pressure on the left side of piston I44 whereupon spring I48 acts to move piston I44 to the left together with piston I to close bleed orifice I50.

There are thus provided novel means for main-. taining substantially constant the speed of rotation of a gyroscopic rotor so that during line surges the pressure at the nozzle is by-passed to compensate for any increase in speed due to such a pressure surge.

Although only two embodiments of the inven- 3. In combination with a fluid pressure driven rotor, a nozzle for directing said fluid pressure tively movable members, one of said members communicating with the fluid pressure supplied to said nozzle and the other of said members being adapted to by-pass fluid pressure supplied to said first member and being resiliently constrained against movement, magnetic field producing means carried by and rotatable with said rotor, and means including a disc connected withsaid other member, and inductively associated with and mounted for angular movement by said magnetic field producing means an amount proand having venting means at the outer. periphery understood by those skilled in the art. For example, provision may be made for compensating for temperature variation in the drag cup torque thereof, a sleeve member surrounding said shaft for angular movement thereon having passages therethrough adapted for communication with said venting'means, means resiliently constraining said sleeve member against angular movement about said shaft, means carried by said sleeve member being angularly movablewith said rotor an amount proportional to the speed of said rotor, and means carried by said rotor for actuating said last-named means for angularly moving said sleeve member against said constraining means thereby providing relative move said directing means, *means mounted for angular movement with said ment between said venting means and said passages whereby the fluid pressure supplied to said nozzle is varied.

5. In combination with a fluid pressure driven rotor,- a shaft mounting said rotor for rotation thereon, a nozzle for directing said fluid pressure to spin said rotor about said shaft, said shaft be: ing provided with means therein communicating with the fluid pressure supplied to said nozzle and having venting means at the outer periphery thereof, a sleeve member surrounding said shaft said rotor and responding to a predetermined speed of rotation of said rotor for angularly moving said sleeve member against said constraining means to bring said passages in registry with said venting means to partially relieve the fluid pressure supplied to said nozzle.

6. In combination with a fluid pressure driven rotor, a shaft mounting said rotor for rotation thereon, a nozzle for directing said fluid pressure to spin said rotor about said shaft, said shaft being provided'with means therein communicating with the fluid pressure supplied to said nozzle and having venting means at the outer periphery thereof, a sleeve member surrounding said shaft for angular movement thereon having passages therethrough adapted for communication with said venting means, means resiliently constraining said sleeve member against angular movement about said shaft, throttling means for by-passing a portion of the fluid pressure sup plied to said nozzle, actuating means for said sleeve member being angularly movable with said rotor an amount proportional to the speed ,of said rotor, and means carried by said rotor for operating said actuating means, said actuating means responding to a predetermined speed of rotation of said rotor for angularly moving said sleeve member against said constraining means to displace said passages relative to said venting means whereby said throttling means are actuated to by-pass a portion of the'fluid pressure supplied to said nozzle.

7. Speed control means for a fluid pressure driven rotor adapted for rotation in a flxed plane comprising means .directing said fluid pressure to spin said rotor, valve means communicating with said directing means, means connected with said valve means and mounted for angular movement with said rotor an amount proportional to the speed of rotation of said rotor and responding to a predetermined speed of rotation of said rotor for actuating said valve means to by-pass fluid-pressure therethrough to vary the -fluid pressure supplied to said directing means,

and means carried by said rotor for operating said last-named means.

determined speed of rotation of said rotor for actuating said valve means to operate said throt tling means thus varying the fluid pressure supplied to said directing means, and means supported by said rotor for actuating said resiliently constrained means.

9. Speed control means for a fluid pressure driven rotor comprising means directing said fluid pressure to spin said rotor, a pneumatic reelay comprising a cylinder having an inlet and an outlet for said fluid pressure and a normally closed bleed means, said directing means communicating with said outlet, a piston mounted for reciprocal movement within said cylinder and closing said bleed means, valve means in restricted communication with said cylinder normally by-passing a portion of said fluid pressure 'from said cylinder, resiliently constrained means mounted for angular movement withsaid rotor an amount proportional to the speed of rotation of said rotor and responding to a predetermined speed of rotation of said rotor for acuating said valve means whereby fluid pressure builds up to move said piston to open said bleed means thereby by-passing fluid pressure from said cylinder thus modifying fluid pressure flow to said directing means, and means rotatable with said rotor for actuating said resiliently constrained means.

10. Speed control means, for a fluid pressure .driven rotor comprising means directing said 8. Speed control means for a fluid pressure driven. rotor comprising means directing said fluid pressure to spin said rotor,,valve means comrotor an amount proportional to the speed of rotation of said rotor and responding to a prefluid pressure to spin said rotor,,a pneumatic relay comprising a cylinder having an inlet and an outlet for said fluid pressure, said directing means communicating with said outlet, a piston mounted for reciprocal movement within said cylinder, valve means communicating with said cylinder normally by-passing a portion'of said fluid pressure from said cylinder magnetic means rotatable with said rotor, resiliently constrained means inductively associated with said magnetic.-

means being adapted for angular movement with said rotor an amount proportional to the speed of rotation of said rotor and responding to a predetermined speed of rotation of said rotor-for actuating said valve means whereby pressure builds up on-said piston to move the latter, and means operable during movement of said piston for venting fluid pressure from said cylinder thereby modifying the fluid pressure supplied to said directing means.

11. Speed control means for a fluid pressure driven rotor comprising means directing said fluid pressure to-spin said rotor, a pneumatic relay comprising a cylinder having an inlet and an outlet for' said fluid pressure, said directing means communicating with said outlet, a piston mounted for reciprocal movement within said cylinder; valve, means communicating with said cylinder normally by-passing a portion of,said

fluid from said cylinder, magnetic means carried by and rotatable with said rotor, a resiliently constrained drag cup associated with said magnetic means mounted for angular movement with said rotor an amount proportional to the speed of rotation of said rotor and responding to a predetermined speed of rotation of-said rotor for actuating said valve means whereby pressure builds up on said piston to move the latter, and means operable during movement of said piston for venting fluid pressure from said cylinder thus modifying the fluid pressure supplied to said directing means. a

12., In combination with a fluid pressure driven rotor, a shaft mounting said rotor for rotation,

thereon, a nozzle for directing said fluid pressure to spin said rotor about said shaft, said shaft being provided with means therein communicating with the fluid pressure supplied to said nozzle and having venting means at the outer periphery of said shaft, a sleeve member surrounding said shaft for angular movement thereon having passages therethrough adapted for communication with said venting means, meansresilient- 1y constraining said sleeve member against angular movement about said shaft, a pneumatic relay comprising a cylinder having an inlet and an outlet for said fluid pressurefsaid nozzle communicating with said outlet, a piston mounted for reciprocal movement within said cylinder, actuating means for said sleeve member mounted for angular movement with said rotor an amount proportional to the speed of rotation of said ro- -tor, means carried by said rotor for operating said actuating means, said actuating means responding to a predetermined speed of rotation of said rotor for actuating said valve means whereby pressure builds up on said piston to move the latter, and means operable during movement of said piston for ventingfluid pressure from said cylinder thus modifying the fluid pressure. supplied to said directing means.

13. Speed control means for a fluid pressure driven rotor comprising means directing said fluid pressure to spin said rotor, a valve com.- prlsing two relatively movable members, one of said members communicating with the fluid pressure supplied to said nozzle and the other being resiliently constrained against movement, magnetic field producing m'eans rotatable with said rotor, and means connected with said other member inductively associated with said magnetic field producing means and mounted for angular movement thereby an amount proportional to the speed of rotationof said rotor and responding to a predetermined speed of rotation of said rotor for moving said other member against said resilient constraint to vary the fluid pressure sup-- plied to said directingmeans whereby the speed of rotation of said rotor is decreased, said angularly movable means being returned to its initial position at decreased rotor speed whereby the fluid pressure supplied to said directing means and the other being resiliently constrained against movement, said valve normally by-pass-' ing a portion of the fluid pressure supplied to said directing means, pressure operated throttling means for said directing means communicating with said onemember, means defining a by-pass normally closed by said throttling means, actuating means connected with said other member mounted for angular movementwith said rotor an amount proportional to the speed of rotation of said' rotor, and means carried by said rotor for operating said actuating means, said actuating means being operative during a predetermined speed oi'. rotation of said rotor for angusilient constraint thereby building up pressure on said throttling means to open said by-pass means thus varying the fluid pressure supplied to said directing means to decrease rotation of said rotor, sai d angularly movable means being returned to its initial position at decreased rotorsaid fluid pressure driven member comprising a cylinder having venting means and-an inlet and outlet for said fluid pressure, and piston means mounted for reciprocal movement within said cylinder normally closing said venting means. said piston means responding toan increased speed of operation of said driven member due to an increased fluid pressure flow through said outlet to open said venting means thereby bypassing fluid pressure from said cylinder thus modifying the fluid pressure flow at said outlet.

16. In combination with a fluid pressure driven member, a pressure relay for maintaining substantially constant the speed of operation of said fluid pressure driven member comprising a cylinder provided with ventingmeans and having an inlet and an outlet for said fluid pressure, piston means mounted for. reciprocal movement within said cylinder, and resilient means normally maintaining saidpiston means in a predetermined position to close said venting means, said piston means being movable against said resilient means in response to an increased speed of operation of said ldriven member due to an increased fluid pressure flowthrough said out let to open said venting means thereby by-passing fluid pressure from said cylinder thus modifying the fluid pressure flow at said outlet.

17. In combination with a fluid pressure driven rotor, speed control means therefor comprising means directing fluid pressure to spin said roto magnetic fleld producing means carried by and rotatable with said rotor, and control means communicating with said directing means and inductively associated with said magnetic fleld producing means for operation thereby to vary the rotor, speed control means therefor comprising I means for directing fluid pressure to spin said rotor, magnetic fleld producing means carried by and rotatable with said rotor, means connected to said directing means for by-passing fluid pressure supplied thereto for modifying the fluid pressure issuing from said directingmeans, and control means operatively connected to said by-passing means and inductively associated with said magnetic fleld producing means for operation thereby.

' larly moving said other member against said re- PAUL A. NOXON.