US2371157A - Governor - Google Patents

Description

GOVERNOR Filed Fb. 27, 1942 2 Sheets-Sheet 1 b S wm. mm e l. s N W. L wm f. m Nw M if@ N5 r uw w Q mw Q Q QSIQ .Ne Q nm .mw @n nw W f f m m A Om. om no. mw G Ow n mK Nm m .E m Nl ,.f/ Nk mm. n V a m I o? m Tm W l# L ,x n l u@ xm Q m mm n W v 2|' March 13, 1945. G. F. DRAKE GOVERNOR Filed Feb. 27, 1942 n 2, sheets-sheet 2 I @ya-Jul T-ro my@ Patented Mar. 143, 1.945l

UNITED STAT-Es PATENT orsi-'cs GOVERNOR George Forrest Drake. Rockford, lll., assignor to Wood a corporation of Illinois ward Governor Company, Rockford, Ill..

' Application February 21. 1942, serial No. 432,519 11 claims. (on. 264-4) Arms I6 on the tlyballs bear-upwardly against the lower race ring il of a thrust bearing having balls i8 supporting an upper ring I9 which abuts against a shoulder 20 on a rod 2i reciprocable in a bore 22 of the sleeve it and carries an enlarged head or piston 23 at its lower end cooperating withA sleeve ports 2t which have a diameter substantially the same as the length 'ofthe piston. The valve thus formed controls the ow or pressure iuid or oil through a groove 2B around the sleeve and a passage 2t leading to the lower end of a vertical cylinder 2l on the l side of the casing opposite the valve structure.

with the movable, element or the servo actuator.

A further object isto arrange the receiving piston of an-hydraulic compensating mechanism within the-servo piston. v

Still another object is to -provide a novel arrangement of springs for modifying the governor action and for restoring normal speed of the prime mover.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with `the accompanying drawings, in which4 Figure l'is a vertical central sectional view of a governor constructed in accordance with the present invention.

Figa-2, 3. l4. and 5 are sections taken respectively along the lines 2 2, 3 3, Land 5-6 of Fig. 1fV

While the invention is susceptible' of various modiiications and alternative constructions, l have shown in the drawings and will herein describe in detail the preferred embodiment. It

is to be understood, however, that I do not intend to vlimit the invention by' such disclosure but aim to covervall modliicatlons and alternative constructions falling within the spirit and scope 7 of the invention asjexpressed in the appended claims.

:In thegovernor shown. vfor purposesoi illusv tration all of the operating parts are housed in? A piston 28 reclprocates in this cylinder and cooperates therewith to form a, servomotor for varlably positioning a throttle rod '2t or other device by which the speed oi the engine is regu lated. Herein the upper end 3d of the servo piston bears against curved surfaces 3i on the biiurcated end of a crank 32 fast on a horizontal rockshaft 33 which is journaled intermediate its endsin a plug 36 which threads through one side of the casing t. The shaft may he connected to the throttle rod through a crank 3b on the outer shaft end, a spring 29a which acts on! the rod providin j the loading necessary to balance the hydraulic forces.

Pressure fluid is supplied by a pump 3B pretera-bly comprising gearsl and 38 disposed in a recess l89 in a plate I0 clampedvagainst the casing bottom, the gear 3l being splinedon the drive sleeve I3. 011 supplied under pressure by the pump is delivered through .a passage il to a` horizontal passage 42 surrounding an external groove 43 formed in the sleeve I3 above the groove 25. The pump inlet is adapted to communicate with an oil supply line 44 through a 7hole 45 in a sleeve 46 connected at its outer end to the lline u with its inner end projecting into the ypassage 42. When an excessive ysupply of pressure' develops. a Piston ll in the sleeve is shifted against'a, spring I8 to uncover a. port I9 and permit the by-passoi oil to the pump inlet.

a casing I usually mounted on the prlme mover `to be controlled and having a tubular extension 1 at its upper open end which is closed by a cover 8. -Chanses in the prime mover speed are detected by upstandlng weights or nyballs l piv.

.'oted' on horizontal pins 'Il on a head Il whichl vrests on aledge' l! ofthe casing. The head is In this Awayfthe oil inthe passage 42 is maintained :atY constant pressure.

"mel tendency `of the urbain colin the pact valve rod i's"counteracted by a main speeder spring il o! truste-conical shape acting between integral with the upper end oi a sleeve iournaled 'in a vertical bore Il with its lower `splined,

end Il projecting from the casing bottgmfior' connection with azsultable drive driven by theoualne. y -i aiwa'sher non Athe upper end ofthe valve rod :band across-headfllf'suided in vertical ways illon' the casing sidewalls. Adjustment of the 'speeder spring stress is effected herein by vturning knurled head Il otra `screw Il; threading into a boss on the casing and bearing at its inner 'endagainst a lug It on a crank. The latter is swung downwardly by the screw.

The present invention contemplates the provision of mechanism self-contained within the,

servo element 28 and responsive to the movement thereof to derive the forces necessary to impart a temporary speed droop characteristic to the governor. Herein, this mechanism operates hydraulically and includes a compensating receiving piston 82 slidablein a cylinder 83 formed by constructing the servo piston as a hollow sleeve. I'he transmitting oractuating piston comprises a plug 64 closing thelower end o! the servo piston sleeve 28. The plunger 82 has a hollow stem 85 with an enlargement 88 guided inthe cylinder 83 and fluted longitudinally as indicated at`81to permit oi' the free flow of oil upwardly from the chamber 88 between the enlargement and the plunger 82.`

Small clearance is provided between an inturned flange 88 on the upper end oi' the sleeve 28 and the portion of the piston rod which projects from the sleeve. By iltting the servo piston or sleeve 28 loosely into the cylinder ,21, oil from thejpressure chamber 28 leaks upwardly along the piston and ilows through holes 18 Vin thesleeve to keep the chamber 68 filled at all times.

The plunger 82 cooperates with the cylinder 88 and the plug 88 to define a chamber 1I whichv is closed except for leakage through an axial bore 18 in the stem 85 as permitted by a needle valve 12 .to control the compensation or restoring action. Preferably. though not necessarily, the

valve is incorporated in the enlarged upperend of plunger stem 88 in a manner to permit leakfrom the chamber 1l through the conage to and supported on a block 88 clamped by a b olt 88 to a bracket 81 on the casing section 1 (see Figs. 3 and 4). The bolt projects through a slot 88 in the bracket paralleling the lever so that the block may be set at diilerent positions along the slot to vary the spacing of the pivots 88 and 82 and therefore the ratio of motion transmission from .the piston 82 to the spring 11.

To provide for etlective return of the lever 8i to its neutral position while permitting the auxiliary spring 11 to exert an eiect which is small as compared to the main spring 88, a second spring 88 is arranged to act on the lever 8|I at a point adjacent the stem 88. YThis spring is substantially stronger than the spring 11 and also acts in tension or compression, having one end fastened to a block- 88 pivoted at 8| on the lever and its lower end attached to a cross-bar 82 which is fastenedto integral ledges 82 on the casing.

Operation When the governor' has attained equilibrium, the parts will be positioned as shown in Fig. l, the chamber 88 being filled with oil by leakage up 'past the servo piston and through the holes 18. 'Ihere will be no pressure in thechambers 88 and 1i, and the springs 11 and 88 exertno force on the lever 8l, the speed setting of the governor being then determined solely'by the spring 88.

First assume that the load .on the engine increases resulting in a decrease in speed. In response to this the ilyballs 8 move in dropping the stantly illled chamber 88 and at the same time be accessible 'for convenient adjustment.` To this end, the valve comprises a needle 13 projecting into an oriiice 18 at the end of a passageway 1 8 drilled in the enlargement 88 and communicat.

ins with the chamber 88; At its upper end, the

passage joinsthe passage 18 extending axially through the stem 88 and communicating with the chamber 1|.` The needle is on a screw 11 .that threads into a bore in the enlarged projecting -DOrtion of the stem at such an angle that the screw head is accessible for adjustment from a'- point exteriorly of 4the servo piston 28.

A novel means is provided for transmitting to the governor pilot valve the forces derived by motio iston 82 as to roduce s d n of the p so p pee .downwardly by the combined tensile forces of droop and then compensate therefor so as to renderthe droop only temporary. This means includes an auxiliary spring 11 acting in parallel with the main speeder spring 88 to either increase or decrease the loading of the ilyballs according to thedirection and extent of movement Vof the compensating receiving piston 82 away from the neutral or equilibrium position Vshovwn the upper end of a rod 18 projecting up through the cross-head 88 and the main spring with its lower end pinned to the upper end of the pilot valve stem 21. One end of the coil is fastened to the rod 18 while the other end is secured to a block 18 pivotally connected at 88 to a horizontal lever 8i iulcrumed on a pin 82 disposedadjacent to the spring. The opposite end of theflever is connected by apivot pin 88 to the upper end of the stem 88 of the receiving piston 82.' To pa'mit the lever ratio to be adjusted as desired. the pin vnisuisposeriin-a slet' um theleverandis pilot valve piston 28 below the ports 24 so as to admit pressure fluid to the chamber 28. This raises the servopiston 28 and through the crank 82 rocks the shaft 88 to shift the rod 28 and increase the throttle opening. At the same time,

the receiving plunger 82 is raised with the servo piston because the valve 12 blocks the rapid escape of fluid from the'chamber through the pasv sages 18 and 18. The lever 8l is thus raised away from its neutral position and the springs 11 and 88 extended correspondingly. The spring 11, being now under tension, counteracts the eil'ect of the spring 88 and in effect reduces the speed setting of the governor so as to permit recentering oi' the pilot valve plunger 28 relative to the ports 28' at a lower engine speed thereby producing speed ldroop and preventing hunting. AWhen the valve becomes rqcentered andthe servo piswn 28 I is brought to rest, the plunger 82 will be urged the two springs 11 and 88, theoil in the chamber 1|v thus being placed under pressure. This oil is permitted to leak out into the chamber 88 l through 'the passage 18, the needle valve 12 and the passage 18 so that the plunger 82 and the lever 8l are permitted to move downward gradually. As an incident to this, the speed setting of the governor is increased progressively so that the servo piston 28 moves to increase the throttle setting still further. This compensating action continues until the original speed setting of the governor has been restored which occurs when, byleakage of oil through the valve 12, the lever '8i and the plunger 82 have been restored to their neutral position with the servo piston and the throttle in their new positions which correspond tothe increased load. The result of this compensating action is that the speed droop initially produced inv response to the speed change in order to secure stability of engine operation is dissi- Ilmd gradually and the initial speed setting of the governor is restored regardless of the servol position and therefore the load on the engine.

In response to overspeeding of the engine, the action above described is reversed. That is, the pilot valve plunger 23 is raised permitting iiuid in the chamber 26 to escape through the drain passage 95 with a consequent lowering of the servo piston land a decrease in throttle opening. As an incident to this,.the plunger 62 follows because the needle valve restricts the uid flow fromthe chamber 68 to the chamber 1I. Thus, the springs 'Il and 89 are compressed and the governor speed setting increased correspondingly. Under vthe influence of spring eiects, the plunger 62 is raised relative to the servo piston as permitted by the now of oil through the valve 12 into the chamber 'Il with the result that the throttle opening is gradually reduced until equilibrium is again restored under the new load condition. The needle valve is of course adjusted to permit the springs to recenter the pilot valve in exact unison with the return of the engine speed to normal.

It will be observed that by adjusting the position of the lever fulcrum 82, the magnitude of the temporary speed droop and therefore the stability of the governor maybe changed as desired. Also, the action of the auxiliary spring 'll is not in any way influenced by the supplemental return spring 89 which latter spring may therefore be as strong as may be required in order to eifect proper recentering of the lever.

By arranging the compensating receiving plunger within the servo piston and transmitting the droop and restoring Amotions to the pilot valve as above described, extreme compactness is obtained, and the construction as a whole is greatly simplified as compared to that of prior isochronous governors. Thus, the addition of the compensating feature does not complicate the construction of the main pilot valve nor necessitate the use of a special connection for driving the iyballs. Moreover, by applying both the speed droop and compensating connections to the upper end of the pilot valve stem and in parallel with the main speeder spring, all of the adjustments are made conveniently accessible.

I claim as my invention:

1. A governorV having, in combination, rotatably mounted, spring loaded flyballs, a servo actuator including a stationary cylinder and a piston reciprocable therein, a pilotl valve actuated by said flyballs and operable selectively to admit pressure fluid to said cylinder or permit the escape of iluid therefrom, a second fluid lled cylinder closed at one end and disposed within said piston so as to move therewith, a plunger reciprocable in said second cylinder, a valve on said plunger controlling the flow of uid into and out of the chamber between said plunger and the closed end of said second cylinder, a lever swingable 1n opposite directions from a neutral position, an auxiliary spring actuated by said lever to increase or decrease the loading on said flyballs according to the direction ,of lever movement relative to said neutralposition, means connectmg said lever to said plunger, and a second spring acting between said lever and a xed point and urging the lever toward said neutral position.

2. A governor having, in combination, rotatable spring loaded yballs, a servo actuator including a stationary ,cylinder and a piston reciprocable therein, a pilot valve actuated selectively by said ilyballs to admit pressure fluid to said cylinder or permit the escape of nuidthereirom, a second 75 5 ber between said plungerand the closed end of said second cylinder, a lever swingable about a xed pivot in opposite directions from a neutral position, means connecting said lever `to said plunger, and means resiliently increasing or decreasing the loading of said flyballs according to the'direction and extent of lever movement away from said neutral position. Y

3. A governor having, in combination, rotary yballs, a main speeder spring loading said ilyballs and selectively adjustable to vary the speed setting of the governor, an auxiliary spring acting on said yballs to supplement the force of said main spring in opposing the centrifugal force exerted on the ilyballs, an element connectedl to said auxiliary spring` land movable in opposite directions -from a neutral position in which no force is exerted'by the spring, said element being movable in Opposite directions away from said neutral position to create forces acting in opposite directions on said ilyballs, a member variably movable in opposite directions in accordance with speed changes detected by said ilyballs, compensating mechanism including a part initially movable with said member to actuate said element and stress said auxiliary spring correspondingly and then to move reversely at a controlled rate whereby to produce temporary speed droop, and a secondary spring means energized selectivelyy in accordance with the direction of movement of said element out of said neutral position and assisting said auxiliary spring in moving the element reversely to said neutral position.

4. An isochronous governor having, in combination, an axially shiftable rod, spring loaded 4o flyballs rotatable around said rod and acting on the rod intermediate the ends thereof to shift the rod in opposite directions with opposite speed changes, a power actuated member, control means associated with one end of said rod and operable to control the application of power to said member to vcause movement thereof in accordance with the rod movement, spring means acting on the opposite end of said rod, and compensating mechanism actuated in response to movement of ysaid power .actuated member and operable tov variably stress said spring means so as to impart a temporary speed droop characteristic to said governor.

5. A governor having, in combination, a rotary head carrying yballs, a main speeder spring coiled about theaxis of saidheadand acting on said iiyballs, a pilot valv'e on the opposite side of said head including a stem having an end projecting through said head and said coiled my spring, an auxiliary speeder spring acting on said projecting end and adapted to vbe stressed selectively to increase or decrease the loading of said ilyballs, an hydraulic actuator energized selec- Y tively underfthe control of said valve and having 55ra movable speed regulating member, and mechanism responsive to the movement of said member and operable to vary the stress of said auxiliary spring and impart temporary speed droop to said governor.

6. An isochronousk governor having, in combination, spring loaded rotary yballs, a lever swingable about a normally fixed fulcrum, spring means connected between said lever and said yballs and being normally inactive when said lever is disposed in a predetermined neutral post.

tion, said spring means operating bymovement of the lever in opposite directions away from said position to respectively increase and decrease the loading of said ilyballs, a second spring means connected between said lever and a iixed point and acting in the same direction as said rst mentioned spring means to urge said lever toward said neutral position, and compensating mecha.- nism actuating said lever to impart a temporary speed droop characteristic to the governor.

7. An isochronous governor having, in combination, spring loaded rotary yballs, a lever swingable about a normally fixed fulcrum, spring means connected between said lever and said flyballs and being normally inactive when said lever said spring means operating by movement of the tion to respectively increase and decrease the loading of said yballs, a second spring means connected between said lever and a xed point and acting in the same direction as said iirst mentioned vspring means to urge said lever toward said neutral position,y compensating mechanism actuating said lever to impart a temporary speed droop characteristic to the governor, and means by which the eiective ratio of said lever may be varied to adjust the stability of the governor.

8. An isochronous governor having, in combination, spring loaded rotary yballs, a lever swingable about a normally xed fulcrum in opposite directions from a predetermined neutral position, spring means connected between said tive when the lever is in said'neutral position, said spring means being energized by movement of the lever in opposite directions away from said neutral position to respectively increase and decrease the loading of said flyballs, and compensating mechanism acting on said lever to energize said spring means and cause the latter to said governor.

9. A governor having, in combination, rotary yballs, spring means exerting a force acting on said fiyballs to oppose the centrifugal force thereon, a servo actuator including a stationary cylinder and a piston reciprocable therein, a pilot valve actuated by said flyballs and operable selectively to admit pressure iluid to said cylinder or permit the escape of fluid therefrom, a second iluid filled cylinder closed at one end and movable with said piston, a plunger reciprocable in said second cylinder, a valve controlling the flow of uid into and out of the chamber between said plunger and the closed end of said second cylinder, said second cylinder, said plunger and said is disposed in a predetermined neutral position,A

' ber away from said neutral position and applying lever in opposite directions away from said posi lever and said flyballs and being normally lnacimpart a temporary speed droop characteristic to a force to the latter to urge the member back toward said neutral position.

- l0. A governor having, in combination, rotary spring loaded ilyballs, a servo actuator including a stationary cylinder and a piston reciprocable therein, aA pilot valve actuated by said flyballs and operable selectively to admit pressure fluid to said cylinder or permit the escape of iluid therefrom, a member movable in opposite directions from a neutral position, an auxiliary coiled spring alined' with the rotational axis of said ilyballs and having opposite ends connected to said member and said ilyballs whereby to add to or subtract from the loading on said flyballs according to the direction of movement of the member relative to said neutralv position, and means connecting -said member to said piston including adashpot having a leak valve for by-passing fluid to permit dissipation of the energy imparted to said spring and restoration of said member to said neutral position following a change in the position of said piston.

11. A governor having, in combination, rotary iiyballs, spring means exerting a force opposing the centrifugal force acting on said lyballs, a servo actuator including a stationary cylinder and a piston reciprocable therein, a pilot valveI adapted to leak and permit dissipation of the said member to energy imparted to said spring and restoration of said neutral position. K GEORGE FORREST DRAKE.

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