US1583610A - Governing mechanism for prime movers - Google Patents

Description

May 4 1926.

' P. H. SCOTT GOVERNING MECHANISM FOR PRIME MOVERS Filed Feb. 26. 1925.

I LU w m3? 2 mm 1 m a M m4 I o w w a e 5 m 5 A .0 Tm m s W NW 5 3 H a I I/I/r/ Patented May 4, I. I I I v un -Tan STATES PATENT OFFICE.

- r1111. 1:. sootrnor Lm, msnoxusn'rrs, AssIGNon "ro GENERAL ELECTRIC com rm, aoonrona'rron on NEW YoRx.

I eovnmmm .uncmnism ronrnmn novnns.

' Application fled February 26,1925. Serial 110. 11,880.

To all whom "it may concern:

- Be it known that I, PAUL H.

zen of the United States, residing at Lynn, in the county'of Essex, State of Massachusetts, have-invented certain new and useful Improvements in Governing Mechanism for Prime Movers, of which the following is a specification.

, The'present invention relates to govermng mechanisms forprime movers such as elastic fluid turbines. In such governingmechanisins there is provided usually a means for adjusting the mechanism so as to set it for the desiredfs eed, such a means in the case of turbines connected to the same bus'bars. Such a means is usually operated by a reversible electric motor termed a synchronizing 1110- invention. Any. suitable valve means arrangement adapted tobe opened and closed tor. The primary objector my invention is to provide an improved construction and arrangement for eflecting'this adjustment;

For a consideration of what I believe to be novel and my invention, attention'isdirected to the accompan 'ing description and the claims appended-thereto.

In the drawing, Fig. 1 isa' diagrammatic view-partly in section of a governing'm'echamsm embodying my invention; Fig. 2 is, a sectional view on a larger scaleof-a part of the mechanism shown in Fig. 1; Fig. 3 is a sectional detail view on a larger scale than Fig.2 of certain of the parts shown'therein; Fig. 4 isa-dfetailsectional view taken on line 4-4, Fig. 3, and Fig. 5 is a detail view of a part of the governing mechanism.

In connection with the drawing, it is pointed out that'my invention is shown as,

appliedto a valve gear of the general type of that shown in the application of Edgar D. Dickinson, Serial No. 692,615, filed Feb ruary 13, 1924.1 However, it is to be-understood that it is not necessarily limited to use with this "particular type of valve gear although as to certain aspects it isparticularly well adapted for such use.

- -Referringto the drawing, 5 indicates the admission end of an elastic fluid turbine to 50 -which elastic fluid is admitted by suitable valve means 6 which is openedand closed by turning movements of a cam shaft 7.

. -The-turbine shaft is indicated at'8 and the oiPtank at 9.- The illustration of the turbine inFig'. 1- is wholly diagrammatic. The

Soo'rr, a citi- I 'ng termed usually a syn chronizing meansin that it;is utilized in, synchronizing alternating current machines turbine casing 5 and shaft 8 are not shown in correct relation to each other butthe turbine casing is brought around into the planeof the paper in order to illustrate more clearly the arrangement of the governing tom of the cylinder by a spring 16 located between the top surface of the piston and a springplug 17 fastened to the upper end of cylinder 15. The arrangement is such that when piston 14 moves'upward it opens valve means 6 and .whenit moves downward it efiec'ts closing of such. .valve means- The .detail structure of the valve means is not illustrated as itforms no part of the present by movements of rod 13 may be used. The

Standerwick, Serial No. 692,601 .filed .Feb-

ruary 13,1924.

.On turb"e shaft 8 is a worm 18 which meshes with a; worm :whe'el 19 mounted on.

-a"vertica1 shaft 20. Shaft 20 is mounted in suitable bearings, one of which is 111- dicated at -21, and at its-lower end is connected to drive an oil .pump 22 located in tank 9. Pump 22 takes oil from tank 9 through a. suitable intake strainer 23'anddelivers oil through a conduit 24 to apipe 25. Connected to pipe 25 is. a pressure re-' lief valve .26 which'dischar'ges back to tank v 9 and which is set to maintainin pipe.25

a certain desired pressure. Pipe 25' de-' I livers oil through an orifice 27 '111 "a plate '28 to a pressure pipe 29 anda by-pass pipe. 30iwhich branc es therefrom. Since will-be delivered through orifice 27 to pipes 29-and 30 always at a definite-rate depending'upon the pressure ez zisting in such pipes.

pipe 29 is conneoted'to cylinder 15 beneath piston 14 and conveys pressure to vthe un derside of the piston for efi'ecting operation of the valve means 6.

in a pilot valve casing 32. 1 In casing 32 is a bushing or sleeve 33 provided with ports By-pass ipe 30 isconnected to an annular chamber 51 formed there is. a constant pressure in pipe 25 oil iw I 34 located in alignment with chamber 31.

Bushing-33 extends well beyond chamber 31 i at each'end and is connected at its upper end to a cylindrical head 35 by means of bolts 36. -Head 35 is provided at its upper end with a threaded opening 37 in which is located a threaded stud 38. On stud 38 are two spaced stops 39 and 40 and on the top of head 35 are two stops 41' and 41 adapted to engage with stops 39 and 40, respectively. In pilotvalve casing 32 is a shoulder 42 upon which rests the lower end of a worm wheel43 carried by a sleeve 44. Sleeve 44 is held in position by a cap piece 45 which is fastened in the top of pilot valve casing 32 by bolts 46., Cap piece 45 forms a bearing for sleeve'44 in which the sleeve is adapted to turn.. Cylindrical head 35 has a sliding fit in sleeve 44 and the two '52 fitsloosely on red 47 and is held against.

are attached together in such a manner that while head 35 canmove axially up ai'id down in sleeve 44 it cannot turn therein. To this end sleeve 44 is provided with a vertical roove 44 in which lies a key 44 carried y head 35. Connected to the upper endof stud 38 is a'rod 47 which projects out beyond the top of the pilot valve casing and has a hand wheel 48 fixed on its end; At the point of connection between stud 38 and rod 47 is a shoulder 49 upon which rests the lower end of -a sleeve 50 which hasa sliding fit in sleeve44. -The lower end of sleeve 50 vis provided with an end wall 51 through whlch rod 47 projects and sur- 1 rounding rod 47 and resting on such end,

wall is a thrust washer 52. Thrust washer wall 51 b'y a spring 53 which 'is compressed between washer. 52 and a plug 54 s which forms a part 'of hand wheel 48. Thrust washer 52 is attached" to rod 47 by a key tional connection betweenv rod 47' andv 55 which is'carried by the rod and fits somewhat loosely in a vertical groove 56 in the washer; Rod 47 can thus move ain'ally through washer 52 but cannot turn relatively thereto. Rod 47 fits somewhat loosely in the opening in wall 51 but is-connected to wall 51 by the frictional engagement between such wall, the shoulder 49 and thrust washer 52. other words, spring 53serves to squeeze wall 51 between thrust washer 52 and shoulder 49, thereby forming a. fricsleeve 50.

On-- the outer'end of sleeve 50 are trim-'- 'nions 50 which engage .furcations .57 on '.'the ends of'arms 57 carried by a bell crank spring-:65 into engagement wi 'onca'msa lever 57; Lever 57 is pivotedmt 58 on a .fixe dj arm 59 and is counterbalanced by aw'eight60. Lever-57 is'connected-by a rod 61 to ahead 62 which slides in a. guider63' and has a roller 64 on .its end pressed by a a cam 66 ,Meshin with worm #1190143 .5 worm "of 11 'yo governor I are connected to each other by. a governorwith the governor,

to the pilot valve.

' valve sleeve connected at its lower "end directly to the" weight arms of a centrifugal. speed governor so as to turn therewith. To this end sleeve valve 73 is fastened to an upper spring plug 74 which is connected to a: lower spring plug a spring 76. The lower spring plug is rovided with a stirrup 77 in which the en s of governor weight arms 78 lie, the end of the arms overlapping each other.

The under arm end is pivotally connected to the'stirrup by a pin '79. The upper arm end is provided with a pivot bearing 80 betweenwhich and a pivot bearing 81 on The engag ng surfaces of the overlap ing spring'plug 74 is located a pivot rod 82. 4

ends of arms 76 are curved so as to roc on 1 each other and are-kept in engagement with' each other by pivot rod 82 which is held in its pivot bearings by spring 7 6. The governor wei ht arms 78 are pivoted on. the arms e 83 by pin bearings 84 and the weights which are indicated at 85 spring 86. Yoke 83 is fastened directly to the upper end of shaft 20. Spring 76 forms a driving connection between pilotvalve 73 and the governor so that the pilot valve turns pivot rod 82 forms a connection between the pilot valve 73 and the governor for transmitting axial movements from the governor When the turbine is running, oil piimp 22 maintains a definite pressure 1n} ipe 25 and the oil flowing through orifice 2 .maintains a definite-.pressure-in pressure pipe 29 and bypass pipe 30 depending upon the extent to whieh ports 34 are uncovered by--p1lot .valve 73, it being understood that when ports 34 are uncovered oil can escape from pi e 30-through ports 34 and the inside of pi ot 73 to tank' 9. The pressure 1n pressure pipe 29 acts onthe underside of piston'14 and holds-it against the action of spring 16 in a position whereinvalve means ened to the extent required .to maintain t e desired speedi- If new the "speed and in conjunction with lid increases the speed governor weights 85 will 7 'move out thus lowering pilot valve sleeve 73 and uncovering further ports 34. This permitsfthe more rapid escape ofjoil from pipe 30 through ports'34 thereby effecting a decrease in the pressure in pipe-29 and that under piston 14' whereu on spring 16' forces piston 14 downward, t erebyturning cam shaft 7 to close somewhat valve means 6 so 'as. to decrease the supply of elastic fluidto the turbine. When ca'mshaft turns it turns also the cam 66 in a direction to permit' spring 65 to move rod 61 toward the left as seen in Fig. 2. This turns bell crank lever .57 in a direction to force sleeve 50 downward somewhat and when sleeve 50 moves downward it carries with it stud 38 and bushing 33. The downward movement of bushing 33 serves to move ports 34 toward pilot valve 73 so as to close the ports somewhat and prevent overtravel or hunting of the-valve mechanism. With decrease in the supply of elastic fluid the turbine returns'to normal s eed again. In case of a decreasein the tur ine speed, then a similar. operation takes place in the opposite direction to eflfect further opening of the valve means so as to bring the speed back to normal. The bushing or sleeve 33 connected to 7 rod 61 in conjunctlon with pilot valve sleeve 73 takes the place of theusual follow-up connection for the pilot valve and operates .to produce the same result.

With the above construction it will be noted that the pilot valve 7 3' is connected directly to the governor andrevolves therewith. This keeps the pilot valve continuously in motion so that there is no danger of-its becoming stuck. The pilot valve 73 may be made ver light in Wei ht so that it places very litt e load onjt e governor weights and'but little force is required to move it axially. A's-a result the governor is required to 'do but very little work so that it may be made smalland extremely simple and sensitive. v 3

Referring now, to the adjustment of the governing mechanism for; difi'erent speeds, this is accomplished by' changing the settingof bushing or sleeve 33 relatively to the speed governor and pilot valve73. Assume for example that the turbine is operating at a certain normal speed and that it is desired to set it fora hi her speed. This'is done by lowering bushing 33 relativelyto pilot valve 73 vso as to close somewhat .ports 34 which results in the building up of the pressure inpipe 29 and a further-opening of valve meansfi. The turbine will then increase in speed and governor weights 85 will thereupon-assume a' new position drawing "down. pilot valve 73 until equilibrium is established at alnew and'higher speed. To

set the governor fora lowerspeed bushing 33 is raised relativelyto pilot valve 73.there.-' by opening further ports 34which efiects a decrease in' 'tl 1e-' pressure under piston 14 -whereupon 1t s lowered and-valve means 6' closed somewhat; The speed of the turbine then decreases and the speed governor as- 'sumesa new setting at the same'timeraisingxpilot valve 73 untilequilibrium is again restored.

the speed of the'machine is effected by means by synchronizing motor 71 which may be controlled by a suitable switch in the usual and 'known manner, it being understood that motor 71 is a khown. type of reversing motor. When motor' 71 runs in one direction it turns sleeve 44 one way and when it runs in the other direction it turns the sleeve the other way. When sleeve 44 turns, it carries with it head 35 and bushing 33 because of the groove and keyconnection 44, 44 Stud 38 is held from turning normally due to its frictional connection with sleeve so that as head 35 turns it will be driven up or down on the threads or stud '38 acthe stops 39 and 40,- such stops being engaged by stops 41 and 41 on the head when the upper and lower limits are reached. \Vhen either pair of' stops comesinto engagement, continued vertical movement of. I

head 35 is arrested and if further operation of the motor inthe same dir'ectiontakes place then, due to the engagement of the stops, stud 38 and rod 47 will be 'turned along with head 35 and bushing 33, the

frictional connection between stud .38 and sleeve 50 slipping. By the use of this frictional connection, I avoid either stalling themot'or or the use of limit switches 'for the motor circuit and I consider this feature one of the important ones in my invention: 1

. By the above described construction it will be seenthat the follow-up mechanism and the-synchronizing mechanism for the governing mechanism arev embodied in a single structure which is compact and comparatively simple jin arrangement. andperation." At the same time it is sensitive and reliable'in operation.

In accordance with the provisions of the patentstatutes, I have described the princi 1c of operation of my invention, together with the apparatus which I nowcon'sider to represent the best embodiment thereof, but I desire to have it understood that the apparatusshown is only illustrative and that the invention may be carried out by other means. y a What I claim as newand desire to secure by Letters Patent of the United States, is z- '1. In a governing mechanism, the combination of a regulating valve means, a fluid-actuated motor including a pilot valve structure for actuating said valve means, a governor connectedto the pilot valve structure,'means for'eflecting adjustment of the setting of the governor, a motor, adjusting means including. africtional connection,

through the-intermediary of which adjustin means said motor moves said meansfor e ecting adjustment .of the setting of the ture for actuating said valve means, a governor connected tothe pilot valve structure, means for effecting adjustment of the setting of the governor, said means comprising two members in threaded engagement with each other'and one of which is held frictionally. I

.member of two engaging threaded members, 7 'one of which is attached to'said axially mov-(vfrom turning, a motor connected with the other member for turning 'it to cause it to move on the first member, and stops for limiting the movement of such other memher on thefirst member.

3. The combination with mechanism comprising a regulating valve means, a'fluid-actuated motor including a pilot valve structure for actuating said valve means, and a governor connected to the pilot valve structure, of means for efiecting adjustment of the setting of the governor, said means comprisin a threaded member,

frictional means or holding it "from turning, a second threaded member on the first;

a governing member, a sleeve, a key and slot connection between the second threaded member and the sleeve,- a motor for turning saidsleeve ,to effect movement of the second threaded 4. In a governing mechanism comprising an axially movable member for effecting adjustment of the setting of the mechanism,- the combination with such axially movable able member, means for holding the other threaded member frictionally from turning,

a motor, means connecting themotor to the threaded member which-is attached to the axially. movable member for turning it whereby there is effected axial movement of it, and stops on-the threaded members for limiting such axial movements, said two stops are in engagement.

In witness whereof,- I have hereunto set my hand this 24th day of February, 1925.

' PAUL H. SCOTT.

threaded members both turning when the

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