US2299824A - Governor - Google Patents

Description

` Octz', `1942. Y A KANN 2,299,824 GOVERNOR Filed July 24, 1941 INCREASES POWER INPUT DEcRgAs Es Q, 1mm

ami n Divided the accumulator is supplied to a governor port E L n andiA continuously therebeyond to one face F of a of prime movers (e1. gf Diesel engi h ubdouble acting hydraulic-servo-motor power piston ject to varyingV loadf" The application isr ivi- Gr.` The port E is'controlled by a lower land porsionofffrny application $erial"f'No.-"f3 y LBfled :5 tion` offap'ilot valvexplunger H-which, if moved Junez, 1941. Tliegovernorl'inechnisni neral@ =downwardlyi lfrom the normal position inrwhic'h ly is "shown herein more forless s ti ally, shown,` opens'thefportlEJto a duct Ileading to the whereas theosame is shown in" l oppositeeffectively larger) face J` of thepower application". l piston;` `causing lupward movement'of the piston. Under certain {condition s` f" n. Upward movement of the pilotA valve plunger from be done t`) ""1`3rirne` movers` `byfatterrlptingf` repeatedly ,its-wnormal position causes'anfupper land portion to increasepowe inputtheretlatftoo high arate. thereof to fopen the duct Iv at a port K,`dumping Diesel" engines'tif opera"ted'atfy nearly? maximum .ipressuresiluidnfromfbelow-tnespowerlpistonginto capacitvloadinglcan beinjured b'yinjectingtoo the sump and causing :the pistonitofdescend by L muc-li fuel during acceleration under load orwhen l5 reason-.ofthe constant` prersurernantained at the V cold." Thepresnt" invention isjconcerndxriainly piston ,face Y f y l l i l y `witl'ianarrangement:for preventingfoperation of The pilot. valve plunger Hismoved vertically aspeed regulating'servo-motor of the governor in in opposite directions as a Aresultof the difference power-input-increasing direction at rates which i `between centrifugalforce on a set` of Hyp-balls L could endanger suclranengine, while neverthe- 20 rotated yby the prime moverand opposing force exerted Jby an adjustable Speeder spring M, so that an increase in speed on part` of the prime moved raises l the pilotlvalve` plunger l and a decrease in speed lowers said plunger. l Regulation `of speedfby the servofmotor incident to` change in loadfds initiatedby such movement of the pilot valvepinger H; o l f Power inputptc the' governed prime mover is increased bysraisingthe-powerpistorr GI Vl(and decreased illy-loweringl the piston) l as 4indicated on thedrawing. "fThusg in governing, fory example, a Diesel engine, increasezrnload?icausesytdecreased centrifugal force; on theflyrballsz and lowering ot tlie;pi1'otvalvewplungeri; thus initiating anincrease inatldelratef.of` supplyffof; duel:tothe;engine; and deceaseli-ntloadi causeslrralsing 4of` the pilot valve plunger #ande consequentifdecrease in the ,rate of supply"alterner..1` arrangement,l -suchfV 'fasA thus I ar described reriulrsiistabilizaticnsin order tofpreventivvacillan neednv or huntingw` consequent upon` load changeandv subsequent;uspeedfcorrecting operation of the governor. The-stabilizing `mechanism lincludesffafhydraulic` compensation Lsystem supiedfwit Lflu'i'd'ifromlgthesump `and-.actuating and delving compensation! pistons oli-f` said J system 'l asiai functionwofiregulatingmovement thels vcexrifotorspistonzGfito-dam11for. check This invention Arela governors of the typead incorporating "the ll f tieni* andlFigf lis; aisectionaly deta 1 "indicated "am-1442 on Fig-1,1

porary overregula on inthe` rime'moverrtherectu'atingaoompeus tion p 'run p'oitinfo liepowelly lacesi hydraulic: fluid in ay ductzlO; leading to the reo ng ompensat-in pistoni -slidablyimounted in a cylindrical extension of the outer pilot valve element, whenever the power" piston G starts to perform a regulating operation in either direction. The motion of the receiving compensation piston P is always opposite the regulationinitiating movement of the pilot valve plunger H, and places temporary primary yielding compensating restraint on each movement of said valve plunger through the intermediary of a coil spring Q connecting the compensating piston P and valve plunger H. 'I'he primaryv compensating force is removed, after regulation is eiected, by relieving the positive or negative pressure in the duct O through an adjustable secondary compensation leak-oi needle valve R communicating the duct O with the sump.

As fully explained in my Patent 2,219,229, the

fly-balls cause continuous rotation of the pilot valve plunger in its coacting fixed valve sleeve through contact of the ball-arm fingers with a disc portion h of the plunger; and the spring Q is so connected with the plunger and receiving compensation piston P that the piston is likewise rotated in its fixed cylinder. possibility of binding of either the valve plunger or said piston due to foreign matter in the hydraulic fluid and assures that the pilot valve is free from friction and therefore free to respondto very slight changes in speed. The spring also allows relative axial movement between the parts connected thereby so that the valve is always free to respond promptly to any change in centrifugal force acting on the fly-balls.

In operation, when the engine load is increased the resultant decrease in speed causes relative inward movement of the fly-balls; lowering of the pilot valve plunger; opening of the port E; admission of hydraulic fluid through duct I to the lower side of the powe'r piston G, and increase of fuel to the engine. The upward movement of the piston G pumps iiuid through duct O; raising the receiving compensation piston P; compressing the spring Q and exerting an upward slight force on the pilot valve plunger suicient to onset the temporary overbalance of speeder spring force relative to the centrifugal force on the fly-balls, thus closing the port E. The port E is ordinarily closed sufl'iciently quickly to prevent overtravel of the power piston in the speed correcting' direction; and, as the engine returns to normal speed,

`the compression force of the spring Q is dissipated by reason of leakage of fluid from the duct O into the sump through the secondary compensation leak-oilr aperture of the needle valve R.

The mechanism operates the same as described above for a decrease in load except that all the movements are reversed, the compensating spring Q being placed in tension by suction action of the compensation fluid system, and hydraulic fluid being finally drawn from the sump into the duct 0 through the aperture of the needle valve R to relieve said tension.

Speed adjusting or changing means is represented by the speeder plug V at the upper end of the speeder spring M. Additional speed changing means would, of course, 'be provided, for example as in my application Serial No. 396,338 of which this application is a division, or in other ways as well known in the art.

' The device I in cooperation with a self closing valve 2 shown at the upper right in Fig. l (I being detailed in Fig. 2) may be called a servo-check" in that the cooperating elements prevent too rapid operation of the power piston G of the speed regulating servo-motor in the power-input- This eliminates the increasing direction during a critical range of operation of the governed engine. The servocheck, however, allows the power piston to move rapidly in said direction an adjustable distance and then damps or checks the remaining travel in that direction, There is no damping in the power-i-nput-decreasing direction, wherefore deceleration and shut-down can always be accomplished quickly.

The servo-check comprises, in part, a body 3 having a cavity or chamber 4 which is in constant free communication with a space T of the servomotor cylinder above the trunk portion of the power piston. The body 3 may be rigidly attached to the servo-motor block U as by screws 5 (one shown) so that the cavity 4 is fully closed from below except at the constant communication passage 6. The space T is kept full of hydraulic fluid from the sump through the valve 2 (gravity opened, upwardly closing ball type check valve, as shown) and the main exit for fluid from said space T is through the passage 6. The valve aperture of the valve 2 in the lowered position of the ball is sufiiciently large so as to place no restraint on movement of the power piston, as during speed decreasing or shut-down movement thereof in respect to the engine.

Inside the body 3, at the left Fig. 2, is a relatively large vertical bore 1 in open communication with the chamber 4 at the lower end of said bore. The upper end of the bore has air vents I. A cup shaped plunger 9 slidably seals the bore 'I so as to block the exit of hydraulic iluid through the bore from the chamber 4, the plunger being biased downwardly by a light coil spring I0 reacting upwardly against an upper wallII of the body. An abutment screw I2 threaded in said vreduced tapered lower end of the needle valve pin.

In operation, as the servo-motor moves from its lowered (shut down) position, fluid is forced through the duct E by raising the plunger 5 from the position shown into a raised position in which the plunger abuts the screw I2. The screw is set, for example, so as to abut the plunger when the throttle moves suddenly from zero throttle to substantially idling throttle position, and thereupon further upward motion of the servomotor piston is retarded in accordance with the amount of restriction set by the needle valve I4. Thus even though the operator habitually moves the s peeder mechanism rapidly from low to high speed setting the engine will always accelerate at an adjusted rate appropriate to long life on part of the engine. The check valve 2 allows unrestricted rate of throttle closure or fuel reduction.

During ordinary governor operation, because it takes a sudden upward surge of hydraulic iluid through the check valve 2 in order to close said valve,'the servo-check mechanism does not operate unless the rate of increase of fuel exceeds predetermined limits. Such limits may be varied by increasing or decreasing (e. g.) the weight of the ball in the check valve 2 or changing the charv acter of the outlet passages around the ball.

I claim: 1. In a governor for prime movers, means operable to regulate power input to the prime mover, speed responsive means arranged to control the operation of the regulating means, speed changing means operatively associated `with the speed responsive means and operable to accelerate and decelerate the primeV mover through the agency of the regulating means, and means operatively connected to the regulating means in a. manner progressively to retard the rate of operation thereof n a speed increasing direction `irrespective of the rate of accelerating operation of the speed changing means beyond a predetermined value.

2. The combination according to claim 1 wherein the rate retarding means becomes operative only after a predetermined unretarded movement oi the regulating means in speed increasing direction.

3. In a governor for prime movers, hydraulically actingmeans operable to regulate `power input to the prime mover, speed responsive means arranged to control the operation of the regulating means, speed changing means operatively i associated with the speed responsive means and.

operable to accelerate and decelerate the prime mover through the agencyy of the regulating means, and Suid-operated braking means operatively connected to the regulating means in a manner to cause relatively slow operation thereof Vduring part of the movement thereof in a speed increasing direction consequent upon operation of the speed changing `means in accelerating direction at an undesired high rate.

4. In a governor for prime movers, a hydraulically operated servo-motor cylinder having a piston therein operable to regulate power input to the prime mover, speed responsive means and speed changing means arranged to control the d and away from the movable means.

operation of the servo-motor, means forming a displacement chamber communicating with the cylinder. the volume of which chamber is diminished as the piston moves toincrease speed, a relatively restricted Iluid outlet for the chamber, movable means forming a yieldably expansible space withsaid chamber, and abutment means operable on the last named means to limit expansion of said space whereby the restricted outlet becomes operative to restrain movement of the servo-motor piston only after fthe abutment means becomes effective.

5. The combination according to claim 4, wherein the abutment means is adjustable toward Y 6. The combination according to claim1 4 wherein the restricted fluid outlet is adjustable in sizewhereby to vary the rate of fuel increasing, movement of the piston.

7. The combination accordingv to claim 4 wherein the displacement chamber `has a substantially vunrestricted inlet so arranged that'the regulator can move unrestrictedly in a. direction to decrease power input to the prime mover.

8. In a governor for primemovers, a hydraulically operated servo-motor operable to regulate power input to the prime mover, speed responsive means and speed changing means arranged to control the operation of the servo-motor, means forming a displacement chamber which is contracted and expanded as the servo-motor movesv to increase and decrease power input respectively,` chamber, a .cylinder communicating with said chamber, a displaceable element slidably sealing the cylinder, and abutment means'arranged `to engage and limit movement of said element in f said cylinder, whereby the restricted outlet becomes operative to restrain movement of the servo-motor only after the displaceable element has moved into contact with the abutment means. i ALBERT KALIN.

-a relatively restricted fluid outlet for the

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