US2375429A - Governor mechanism - Google Patents

Description

'May 8, 1945. v

7 GOVERNOR MEcHANIsM Filed slept. 2, 1942 1 AT1-ORN B. MARTIN 2,375,429

Patented May 8,'I 1.945

GOVERNOR MECHANISM Thomas B. Mtiutin, Dayton, Ohio, assigner to General Motors Corporation, Detroit, Mich., a

corporation of Delaware Application september 2, 1942', serial No. 457,032

(c1. 17o-16s) 12 Claims.

This invention relates to regulators for uid actuated controllable pitch propellers, and has for an object to provide means for regulating an operating propeller in response to acceleration or change of speed of the propeller.

A further object is to provide means in conjunction with a constant speed propeller for effecting regulation in response to a spurt or las of controlled speed.

A still further object of the invention is to provide means and mechanismfor controlling the shift of propeller pitch for constant speed operation, and then superpose control means upon thc constant speed effected for nely adjusting the resulting speed.

Yet another obi ect is to provide means respond'- ing to angular acceleration of the propeller shaft for anticipating a speed change before it actually occurs to any great extent and for applying the anticipated speed change to correction of blade pitch.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein apreferred embodidrive-shaft I2 for driving a propeller hub I4 parts shown in elevation and illustrating an adaptation of the instant invention.

Fig. 2 is a view oi'` part thereof but on a much enlarged scale.

Fig. 3-is a detail view in section with parts ,shown in elevation substantially as indicated by the line and arrows 3-3 of Fig. 2.

Fig. 4 is a detailview in top plan with parts shown in section substantially as indicated by the line and arrows '6 4 of Fig. 3.

In controllable pitch propellers that involve the useof a governor mechanism for the control of the blade pitch to a constant speed it is necessaryfthat there be a change in speed before there can be any consequential change in blade lation of theconventional control means. In the present instance, use is made of a pendulm situated within the reservoir that rotates with the vregulator mechanism and is so pivoted that itv vwlllrcspond to angular accelerationy or speed 5 providing a plurality of blade sockets I6. In theA blade sockets torque applying units IIare sit` uated and have operative connections with the roots of blades I8 for twisting them about` their longitudinal axes in response to fluid pressure applied to one or the other of the transfer tubes 20, 22 and to relief through the other. 'Thedif rection of the torque applied to the blades is de-l sure is applied to, which in turn is determined by the operation 4of a regulator mechanism 24 mounted on `and rotatable with the propeller.

. Pressure applied to tube 20 is admitted to one side of the piston I9 of the torque applying unit and due to the double spiral. spline engagement 2I on 23 causes rotationA of the blade in one direction, while pressure applied to the opposite side of the piston I9 causes rotation of the blade in the opposite direction.

For mounting of the regulator the hub I4 is extended rearwardly along the shaft I2 to provide a sleeve 26 on which is piloted a regulator plate 28 as shown in detail in Fig. 1. The plate is of annular' formand seats against the .aft side of each of the blade sockets I6 where it -is held by means of a sleeve nut 30 threaded onto the sleeve` extension 26 of theihub. Fluid passages comprising tubular inserts 32 and 34 and perhaps others, are embedded in the body of the plate and are so arranged as to join up with transfer pas- Sages 38 and 38 respectively communicating with the tubes 20, 22 when theregulator plate is moved vices 46. An end plate 48 may be inserted there- Since the inner portions l29 and;

tain a measured quantity o f fluid pressure medium which for the most part substantially immerses the control mechanism. It is intended that the regulator mechanism-shallbe self-contained in all of its 'duid circuits and partsito the inclusion of pressure developing means and pressure distributing means 60. The pressure -developing means, sucli'as a constant delivery pump may be driven from a toothed ange 51V extending from the fixed sleeve 43. 'I'he plate 28 provides definite stations ony the inside of the reservoir where the various control elements shall be mounted, and is usually accomplished by incorporating mounting pads or juncture blocks making'proper connection with the embedded tubesor passages so that mere mounting of the particular elements oi' the control mechanism in their designed places will automatically connect them into the fluid circuit at the proper point.

One suchz station is indicated by the pad 82 shown in the drawing and to which a pressure supply tube 64 and the control passages 32, 34 are Joined so as to be accessible to the pressure distributing means 60. The particular 'form of pressure distributing means illustrated constitutes a governor valve mechanism of unitary construc-` tion whose movable valveparts provide centrifugally responsive elements opposed by spring presledge or saddle |04 on which seats a spring |00. A rigid lug or other extension |08 at the opposite end of the block provides a rest for the seating of said lspring at the other end and provides a rigid point from which the spring force may be applied in opposition to centrifugal force applied on the valve body when the regulator is rotating.

The governor valve mechanism so constituted is adapted to be mounted with its machined face ||0 directly over the mounting pad or juncture block'62 so that the chambers 88, 10, 12 make fluid connection with ports or passages in the juncture block leading to the supply passage and control passages, and with the lever 82 at the inboard end of a radius of rotation. When so mounted the movable parts of the mechanism, that is the valve plunger 84 and, the lever 02 form weight members responding to the action of centrifugal force in a manner tending to compress the constantly acting spring |06. Under a condition of rest the valve plunger will be pro- `ected radially inward so as to move the'plun'ger to an in position in which the pressure ports nism which rotation increases until the centrifusure for controlling the propeller mechanism to operate at asubstantially constant speed to be selected -lby hand from a point outside of the regulator. l

Toward that end the governor valve mechanism includes a block 36 chambered at 68, 10 and 12 for uid connection with the earlier mentioned pressure tubes and control passages.' Secured .within a fbore of the block intersecting the chambers is a sleeve or liner 'Til that has groups of holes 16, 18, 80 that o'pen from the interior of the sleeve into each of said chambers. One end of the sleeve is headed or otherwise provided with stop means 82 for holding the .sleeve properly positioned in the block, and a cross pin may be added at the other end for the same purpose. A

valve plungerd is adapted to slide along the bore of the sleeve v'N and has a pair of spaced lands 86, 88 so positioned as to substantially stop flow through all of the ports of the groups 16 and 80 respectively 'when the valve plunger is in the equilibrium or mid position.

An extension of the plunger 8B provides a po tion 90 to which Ais pivoted a lever 92 through gal force acting upon the movable elements of the valve mechanism balances the opposing spring force, at which time the valve plunger occupies an equilibrium position in' which iluid flow is substantially stopped through either of the control ports I6 or 80. The propeller mechanism will then operate at a substantially constant speed untila different speed level is selected. Slight domination of either centrifugal force or spring force will shift the valve plunger d outward or inward respectively from the equilibrium position and result in a consequential application of iiuid pressure from the supply port 'i8 either tothe port 80 forpitchincrease application or to the port It for pitch decrease application. The

y the corrected speed of propeller rotation, to the which the valve actuating force is applied. A

4guide plate 94 is fixed at one end to an end of the 'block 66 b'y means of screws 96 and has a pair of guide arms 98 extending away from the block to slida'bly 'Support a carriagejll. To reduce resistance of sliding movement the carrier |00 is provided with rollers i 0| that roll upon the ways 98. A fulcrum roller |02 vis carried by the carriage i 00 and is adapted' to support the extended or free end ofthe lever 92. A convenient form of the lever 92 is that of a yoke having two such arms in parallel each resting on a fulcrum roller and providing between them at the bite a extent that a pitch increase application will increase the load upon the engine to reduce its speed and the accompanying centrifugal force, by which the valve plunger regains its equilibrium position. Similarly, a pitch decrease lessens the load and-is followed by an increase of engine speed and centrifugal Aforce to bring the valve plunger back to the equilibrium position.

Selection of the different speed levels is accomplished by moving the fulcrum 02 relatively nearer .to or further away from the point of applied spring force opposing the centrifugal force. Upon reference to Fig. 2, it will be noted'that moving the fulcrum forward toward the valve plunger operates to shorten the length of the lever arms through which the opposing forces are applied to the ,valve plunger 84.' However,

K the length of the arm between the fulcrum and lthrough the end of the ways prevents vfrom the axis of rotation.

. e '2,375,429 spring force. When those conditions obtain.l then the mechanism will control at a lowex` constant speed than when the fulcrum is ata point near the aft end of the guideway. A, cross-pin ||2A l r l the carriage from disengaging the wayaf. Movement of the fulcrum |02 is accomplished by means of a control ring ||4 slidable axially of 'l the sleeves: and retained against rotation reis-v i t tive thereto. The control ring' ||4is grooved to slida'bly receive a shoe |20 extending from the carriage |00. Thus movement of the controlring fore and aft along the sleeve 42 carries with it the carriage |00 and results in movement of thel fulcrum |02 toward or away from the point oi spring force.

through the aft portion of the adapter assembly supporting the sleeve 43, including a guide-ring disposed between the end of the sleeve 43 and the mounting ring 40. A thrust collar |28 and a pinion |00 limit endwise movement of each screw shaft, and the pinion |00 engages a ring 's shoe |20. Ii the pendulum swings tothe other 81de, Bay 1101MB. then the i'ulcrum'will be moved inthe other direction. jy `fllhe consequential amount of movement for tl'leifulcrum under the pendulum control is designedly's'mall sc that the-control function will be inaugurated almostbefore there is an actual change of speed..l

- 'Considerinsn that manual movement .of the move'the fulcrum roller |02 fore or aft to alter absorption changes in such a way as to cause a decrease in speed the pendulum `will tend to advance 'inangular position and thereby effect such shift ofthe fulcrum roller |02 as to sive the y spring force a slight advantage over the centrif-` ugal force. The dominating spring force shifts the valve plunger inward a slight amount to con-` neet the pressure port 1u with the control port 1S and thereby appli' a pitch vdecreasing impulse 'to the torqueapplying unit oi the blades. In like manner an unbalance' of forces tending to cause gear |32 mounted yfor` oscillation in the space between the guide ring |20 and the mounting ring 44. The ring gear- |02 is provided'with a lug |34A apertured at |00 for linked or cabled connection with a manual or instrument control located in the pilots compartment, or elsewhere, and completes the hookup for outside control of the parts situated within the reservoir 40. vlay oscillation of the ring gear the control mechanism C may beset at a. new speed level while the propeller is-rotating, thereby superimposing manual an increase in propeller speed will result in domination oi' the centrifugal force which shifts the valve plunger 80 outward to apply a pitch in- As the ring gear is movedin one direction it 4rotates the screwsharts due to the geared en gagement wlththe pinlons |30, fand the screw riage |00 which carries the fulcrum toward or e away from the point of spring pressure.

The regulating of speed change anticipating mechanism comprehends manufacture of the carriage in t'wo cooperable and relatively shiftable parts, one, |40 supporting thefulcrum rollers on its threaded end the nut |40 which has on its exterior surface a coarse pitch thread |48 engaging the part |40. The nut |40 extends to the rear of the part |40 and there receives a pendulum |00 secured by a screw device |0|, whose weight |02 extends generally radially outward The screw |44 being secured in the part |42 against rotation and cooperating with the double pitch nut aords a dierential screw 'device or screw jack for shifting the carriage parts |40 and |42 relative to each other upon-v swinging of the pendulum |00 to either side of the medial position. With respect to Fig. 3. if the pendulum swings to one side, say to |02L as shown in the drawing, the iulcrumy |02 will be moved in4 one .7"

dlrectionalong the ways 00 with respect to the l claims which follow. shafts -in turnI move the control ring alongl the sleeve 43 with a resultant movement of the carcreasing impulse to the torque applying units. Thus, the pitch of the propeller blades is shlited quickly in response to angular change in speed at the very earliest indication of change in propeller rotation. However as soon as the forces again balance, the propeller blades return to the original position.

While the embodiment oi the present invention l as herein disclosed, constitutes ,a preferred form. it is to be understood that other forms might be adopted, all coming within the scope of the What isfclaimed is as follows:

1. In a controllable pitchpropeller, a reservoir rotatable therewith and charged with a quantity of pressure actuating fluid, iluid pressure actuated control mechanism enclosed within the reservoir and operable upon rotation of the propeller for effecting pitch shift ofthe blades thereof toward constant speed operation, said control mechanism comprising, a governor valve unit including centrifugally operated means for se sure actuated control mechanism enclosed within the reservoir and operable upon rotation of the propeller for effecting pitch shift of the blades thereof toward constant-speed operation,

' said control mechanism comprising, a governor mechanism with connections for effecting constant speed operation of' said propeller, and including a valve member adapted for movement y from an equilibrium position in response to dominating spring and opposing centrifugal force. means for predetermining and selecting the speed level Vat which the opposing forces will be in equilibrium, and means including an oscillatable means and responsiveto angularccelertio the propeller for biasing the valve member to a -corrective position.

3. In a controllable pitch propeller `having a reservoir rotatable therewith andcharged with 'a quantity of pressure actuating-fluid, fiuid v pressure actuated control mechanismenclosed'.v

within the reservoir and operable upon rotation of the propeller for effecting pitch shift of the blades thereof toward constant speed operation,

said control mechanism lcomprising, a governor mechanism with connectionsl for eifectingconstant speed operation' of said propeller, and including a valve member adapted for movement' from an equilibrium position' in response tofdorninating spring and. opposing centrifugal force, means for predetermining the speed l level at which the opposingforces will be in equilibrium, including a movable fulcrum, a lever resting on' the fulcrum and pivoted to the valve member I. and Vacarria'ge for movingthe fulcrum toward and awayfrom the valveimember, and means for applying slight movement to the fulcrum in response to angular acceleration of the propeller.

4. Theffcombinationset forth in claim 3, in which the carriage comprises a pair of relatively movable-'parts one of which carries the fulcrum, and-a pendulumoscillatable ina plane parallel with theplane of rotation is adapted to'move one part of thecarriage with respect to the other for effecting the slight fulcrummovement.

5. Thecombinationset forth in claim 3, in which the carriage-comprises a pair of relatively m'ovablaparts one.of which carries the fulcrum,

a diierential screw connecting the carriage. parts4 and adapted on rotation to move one of-the car= riage parts relative to the other, and a pendu` lum for turning the di'erential screw upon change of speed of the propeller whereby the said slight fulcrum-shift is accomplished.

6. hydraulically actuated controllable pitch propeller comprising in combination, torque ap plying-units for changing the angle of attack of the bladesmf said, propeller, a liquid containing reservoir, mounted on the propeller, fluid pres;4 sure passagesnconneoting the reservoir with the 1 torque/applying units, and pitch controlling" means-enclosediby'the reservoir including gov-,

peller and opposed. by spring force, a.movabl' fulcrum, a lever bearing on the fulcrum for trans-` mitting spring force to said valve member, means for moving-the fulcrum to and from the valve member to vary the relation of the .centrifugal and spring .forces acting thereon for v,selectinguai speed leve1 .at which regulation will be effected,

and means operable upon thefulcrum'to change its positiomautomatically in response to angular accelerationof thepropeller.

7. The a com inatii;in4 stforth in claim 6, in which agdivide'd carriage supports the Lfulcrum' and isd actuatable from outside the reservoir while the propeller is operating for,the selecting of a speed level, and in which an inertia ,mem-Q ber operates to shift a part ofthe carriageand thereb'ylrthe fuIcrnm. position in :said 'response to angular 4 accelers'ition of the propeller mecha- 8..'ln-atcon`stant speed propeller mechanism '2,375,429 pendulum operable -upon fthe precletermining- "-A a hydraulicfregula' 1 0-s in spaced relation on either side of thel lever,

rotatable with'the propeller and containing control mechanism for eil'ecting change in blade pitch in response vto v change inl speed of propeller rotation, the com- I 5 bii'iation comprising, a governor valve and lever pivotally connected-therewith adapted for movement in a plane-normal'to-.the d isc of' propeller rotation, a ported housinglocating the valve substantially on a radius of the d isc ofrotation, axial extensions from the housing disposed afulcrum forthe lever carried by one, ofthe extensions, yielding means .operating from the other of said extensions to bias said lever against movement by centrifugal force of propeller rota- `tion,`and means for shifting the fulcrum toward angular acceleration of said propeller.

g; in, acarriage supports the fulcrum and. is constantlyuoperablefrom outside the regulator for selecting a different speed level for which the propeller speed shall be'controlled, said carriage being divided into '.'two parts movable as a whole from outside of the regulator and one partV thereof carrying the fulcrum and movable with respect to the other part by said acceleration responsive means within the regulator effecting to angular accelpart by an inertia member "within the regulator for eii'ecting the said ,fulcrum shift responding to angular acceleration of the propeller. 40 y 1l. In a rotatable hydraulic regulator of the class described, a governor' valve unit rotatable with the regulator and comprising in combination,- a ported housing extendingradially of the axis of rotation, a pilot valve movable in the `housing to cover and uncover the ports therein 'upon change in centrifugal force, a lever pivoted to the valve and `extendingfrom'the housing, guide ways extending in. spaced relationto ,the lever, a carriagemovable along the guide .P ways and providing a"fulcruin roller for supporting the extended end of;fsaid lever, means constantly biasing the. lever against said fulcrum j roller, rotation ofthe valve uhit'establishing a balance between centrifugal forcethereof and sgfthe biasing means.l whereby the ports of the `housing are ooveredby. the pilot valve, means ion-setting. the. position of the carriage alongI thef'guide ways, and'.means responclingtov a rate of change in speed of rotation of. said regulator for moving therfulcrum roller valong the lever relative toggthe carriage includes a threaded stud l gsecured infonie part of .the"carriage, a differential'nut threaded ontothe stud and into a 'movablepart of thecarriage, and wherein said means responding to a rate of, ,ch ange of speed includes en .in'ertia member for' turning the nut whereby fm'shif't'iof the vvalve member is madein .anticipalatr.

. THOMAS B. MARTIN.

l land away from the valve member in response to thereof being movable .inrelation to the other ;offlchange speed of rotation of said regu,

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