US2371793A

US2371793A - Governor

Info

Publication number: US2371793A
Application number: US467732A
Authority: US
Inventors: Ira R Bourland; Arthur A Heavener
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1942-12-03
Filing date: 1942-12-03
Publication date: 1945-03-20
Anticipated expiration: 1962-03-20

Description

Patented Mar. 20,

UNITED STATES ,i

PATENT ori-'lcs ener, Western Springs,

lll., assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware A Application 3, 1942, Serial No. 467,732

1 claim. (ci. zei-4i 'I'he present invention relates to speed responsive governor control mechanisms generally, and

.more particularly to adjustable compensating means for such mechanisms to modify the action thereof. v

It has been found that speed responsive governor mechanisms `for controlling the speed of Vprime movers tend to cause Vover and under speeding and over and under loading thereof and by a speeder spring I'I which surrounds a two part telescopic guide member shown generally at I3; the spring and guide' member being 1ocated between the collar I3 and a cam 2l on a 5 manually operable speed setting lever 23 which is pivoted to a bracket 2| fixed to the housing I. Movement of the cam 2| by the speed setting lever 23 varies the tension' of the speeder spring to vary the speed response of the speed responhunting of the governor mechanisms whenthe l0 sive means or weights 3 in the usual manner.

- governor speed setting means or external load on the prime mover is varied widely and suddenly.

The' principal object of the present invention is to provide simple and readilyadjustable compenanisms of the above mentioned type sothat the governor mechanism will act upon eitherl av gradual and small change or upon a sudden or wide change in either the governor speed settingr a The valve mechanism, in addition to the pilot valve I5, also includes a valve sleeve 25 concentric with the pilot valve. They pilot valve vand 4 sleeve are both returned to the relative positions sating means for speed responsive governormechl5 in which they are shown by compensating means and centering means which will be described, when the speed, load and output of the prime Y mover are at a constant valuefor any particular speed setting of the governor. The pilot valve is similar change inthe load on the prime mover, 20 provided with two axially spaced landsr 21 and properly to adjust the actuating iluid suppliedto the prime mover so as to prevent over or under speeding and loading of the prime niover` hunting of the governor mechanism itself.

29 which are movable in fluid tight relation within the valve sleeve 25, which is also movable in fluid tight relation in a vertical bore 30 in the `housing I. The valve sleeve is provided with The adjustabiecompensanng means by which ,mree axially spaced radial ports al, :s and is;

the above object is accomplished willbe better. understood by referring to the following detailed description and operation thereofand, the accompanying drawing illustrating these means inthe port 33 being shown covered by the pilot valve land 29 andthe ports 3I and 33 being shown on opposite sides of the land 29. Three annular grooves are spaced axially with respect to the corporated in a speed responsive governor mecha- 30 bore 30 and adjacent the portsl in the sleeve to nism of the isochronous type having duid pressure operated control and compensating means.,

Figure 1 of the drawing is a schematic vertical cross sectional view of a governor provided with ouxl adjustable compensating means.

Figure 2 is an enlarged crosssectional view of one element of our adjustable means, and

Figure 3 is a cross sectional view taken on line 3-3 ofFigure 2. l

. Referring to Figure 1; the complete igovernor .40 vertical bore 31 in the housing I; which serves as Y mechanism is shown included in a housing I which may be supported in any convenient manner on the prime mover to be controlledf The governor speed responsive means comprises centrifugal weights s pivotauy mounted 4f" on a gear 5 which is 'rotatably mounted in the housing. I and operating in mesh with .a driving gear 'I nxed on a shaft 3 which is also rotatably mounted in the housing I and adapted to be conweights 3 are prevented irom outward movement fof the dpower cylinder.

32 to which apipe 33 is connected. The pipe 33 35 is adapted to be connected to a constant pressure iluid source from the prime -mover driven \oil pump and pressure vregulating means, not shown.

' Thecentral annular groove adjacent the port 33 is connected by a horizontal passage 3l to a a power cylinder, in which a power piston 39 slides in fluid tight relation. The lower annular shown, which is maintained at atmospheric presl l sureatalltimes.

The vertical bore 31 in which the power piston 'v slides is closed at its upper extremity by-a mem- -nected in any well known manner for rotation ber 43 which is threaded into the housing I'and provided with a vent hole` M. A compression spring l5 is placed between the member 43 and the power piston normally to bias the power piston downwardly to the lower end of the b'ore 3l The rupper annular slides.

threaded therein and has a vent hole 54 and a bore 55, in which the lower portion of the,pis ton rod 41 is slidably mounted. The lower end of the piston rod 41 has a clevis 51 xed thereto by which the prime mover fuel regulating means,

not shown, may be connected, so that when the power piston is moved to the lowest position in the bore 31 the prime mover fuel regulatorismoved to reduce the fuel supplied to the prime mover to a minimum value.

The upper end of the bore or cylinder 5I in which the compensator actuating piston 49 opcrates is connected by a horizontal fluid passage 59 in the housing I to' the upper end ofa bore 6I therein which is below and in axial alignment with the bore 30 in which the valve sleeve 25 A compensatingreceiving piston 93 is secured to the lower end of the sleeve'25 and moves in fluid tight relation in the bore or cylinder 6|. An abutment 55 is threaded into the lower end of the bore 8l. A horizontal uid passage -81 extends from a point immediately above this abutment and has a pipe B9 connected thereto for interconnecting the passage 61 to the Pipe 4I which, as previously mentioned, is connected compensating pistons is also connected to the sump through the relief valves shown generally at 85 and 81, to be described.

The compensating receiving piston. 53 is provided with an'enlarged diameter piston rod por- 80 from the passage 5,9 to the sump by uid connec- 'I1 to allow lmovement of the nut 82 relative to the abutment.

It will be evident that the above described combined means serves as motion limiting and retarding means and also positioning means which normally holds the valve sleeve and compensatin-g receiving piston B3 in the normal centered position shown. The spring 8| opposes movement of these parts upwardlyY or downwardly from this position; the maximum permissible movement of the sleeve and piston being equal to the distance separating the collars,

which distance may be a-djusted by the placing of l shims between the collars or between the collars and abutments. When shims are placed between the collars andA abutments the tension of the spring 8| is also changed.

The other adjustable elements of this governor adjusting means are an adjustable pressure operated equalizing or relief valve shown generally at 85 in Figures l, 2 land 3 and a manually adjustable needle valve shown generally at 481 in Figure l. Both of these adjustable valves modify the movement of the compensating receiving piston 63 with respect to that lof the compensating actuating piston 49, because both of these adjustable valves communicate with the passage 59 between the spaces above the compensating

pistons

49 and 53 and provide communication tions to be described. The sump, as mentioned previously, is maintained at substantially atmospheric pressure at all times and therefore both of thesey valves serve to control the rate 86 of equalization between the .pressures in the to the pump sump. The passage 59 between the spacevabove the compensating pistons and thecylindrical valve housing member 9| threaded into ment 65 and the portion 13 extends into a bore 45 15 in axial alignment with the bore 8|. An abutment 11 is threaded into the lower end of the bore 15. The space in the bore 15 between the upper abutment 65 and the lower abutment 11 contains adjustable valve sleeve centering means, shown lgenerally adjacent the character 18, for limiting and retarding follow up movement of the valve sleeve 25 with respect to the.

pilot valve I5 and for returning the valve sleeve 25 and attached compensating receiving piston 63 to the normal position in which these parts are shown. This combined adjustable motion limiting and retarding means and sleeve positioning or centering means constitutes one element of one governor adjusting means and comprises col lars 19 slidably mounted on the piston rod portion 13 and a compression spring 8| placed between these collars 19. A nut 82 threaded on the lower end of the piston rod portion 13 holds the collars and compression spring in the above described positions on the piston rod portion 13, as shown. The Vspring 8| tends to constantly urge the upper collar into contact both with they the lower end 'of a vertical bore 93 in the housing I which extends into the passage 59. The internal diameter of the hollow valve housing is less near its central portion than at'its end portions and the annular surfaces formed adjacent the extremities of the smaller internal diameter portion serve as fixed abutments. A piston valve 91 is slidably mounted iniiuid tight relation in the smaller internal diameter central por- -tion of the valve housing 9| andv is of the same axial length as this portion of the housing. The piston valve 91 is normally held in the position shown; that is, with its upper and lower edges ilush with the annular abutment surfaces 95 of the housing, by two hollow movable abutments IIII on either side of the valve 91 which are biased into contact with the upper and lower edges of the piston and the iixed housing abutment surfaces 95 flush therewith, by compression springs |93 placed between the movable abutment members IIlI and fixed abutment members |05 and `I01 threaded in the upper and lower ends of the larger internal diameter portions of the valve housing 9|. The upper xed abutment |05 is provided with an axial bore |08 which provides communication between the passage 59 in the housing and the upper face of the piston valve 91, and has a conical outer surface which is held in fluid tight contact with a complementary sur- 15 radial passages III and IIS extend from the bore |33 to spaced ports I|3 and I|1 in the piston valve. The portion of the piston valve "between the ports ||3 and ||1 normally covers ports ||3 which extend radially through the walls ofthe valve housing 3|. Another opening |2| is provided in the valve housing wall adjacent the lower nected by a vertical passage |21 in the housing which has a pipe |23 connected lthereto for con necting the passage |21 to the sump.

With the parts of the pressure operated valve arranged as shown. the piston valve 31 is moved upwardly or downwardly from the normal position, in which. it is held by the springs |03, by

differential pressure between that in the passage 33 and that in the sump, since the upper face of the piston valve 31 is subjected to the pressure in the passage 33 and the lower face of the piston valve is subjected to atmospheric pressure in the. sump.. I'he tension of either of the `springs |03 may be varied by placing shims between the springs |33 and abutments |01-or |03 on either side thereof, to resist movement, of the`piston valve to either open position where the port ||3 in the valve sleeve housing 3| .is connected to either the upper port ||3 or lower port ||1 of the piston valve 31 by downward or upwardmovement of the piston valve which then connects the passage 33 between the compensating

pistons

33 and 33 to the sump to relieve the pressure above or below atmospheric in the passage 39. It will be evident that the piston valve 31 may be caused to move to either open position at any desired value oi'` pressure either above or below atmospheric by varying the tension of either of the springs |03.

As best shown in Figure l, the manually operable needle valve 31 includes a stem |23 threaded vinto a cap |3| which is threadedy into the'lower end of, a vertical housing bore |33 having an upper portion of reduced diameter or oriiice |35 openingv into the passage 33 which interconnects the compensating

pistons

33 and 33. A drilled passage |31 ls provided inthe housing. to coni nect the bore |33 to the passage |21 and pipe |23 which is connected. to the sump. The upper end of the valve stem |23 is provided with a conical end portion which is adjustable with respect to the orifice |33 to vary the rate ofnuid iiow be tween the sump and the passage .33 which interconnects the compensating pistonsin order to vary the rate of pressure equalization between this passage and the sump. A knurled portion will move rapidly outwardly and move the pilot valve Il rapidly upwardly causing the land 23 of the pilot valve to uncover the `port 33 in the valve sleeve 23. This allows the iluid which is under pressure under the power piston tn pass out to the sump through the passage 33, ports 33 and 3i of the valve sleeve, passage 33 and pipe 3| connected to the sump. The power pistonwill accordingly start moving rapidly downwardly by action of the spring 35, to cause a reduction in the fuel supplied to the prime mover which will reduce its speed. Since the compensating vactuating piston 43 is connected to the Y power piston, it will also be moved rapidly downwardly and'cause. a sudden reduction in pressure in the vuid passage 53, which interconnects the compensating actuating piston with the compensating receiving piston 33, to cause the latter to move rapidly upwardly in follow up relation with respect to the pilot valve.V The rate of upward movement of the compensating receiving piston 63 and the valve sleeve 23 connected there` to is limited by both the amount of fluid allowed to pa'ss through the orifice |35 of the needle valve 31 from the sump to the passage 53 between the compensating pistons. which tends to relieve the Areduction in -pressure therein, and also by the tension of the spring 3| of the motion limiting and retarding means described which is connected to the compensating receiving piston and l valve sleeve. As vthe needle valve 31 is normally which is maintained at atmospheric pressure. f

'I'his sudden increase in pressure inthe passage '33 to that of the sump is suiiicient to substan- |33 isZ provided on the lower end of the vitlvesteml |23 to .facilitate adjustment of the valve stem-|23 with respect to the orifice |33.

With the various parts of the governor mechanism in the positions shown. the prime mover will be caused to operate at a constant value of lspeed and load equal to half itsmaximum value. With the described adjustable means properly ad'- iusted, the operation of the governor mechanismA will be in accordanceV with the following description when `there is a wide and sudden reduction in the tension of the governor speeder spring I1 to reduce the speed setting of the governor or upon a wide and sudden. increase in the speed of the prime mover due tc. a wide and sudden reduction in the load on the prime mover.

,Inres'ponsetoeitheroftheabovesuddenand wide changes. the governor centrifugal weights adjusted to allow only a small` amount oi uld to ow therethrough, the valve sleeve and cornpensating piston will move upwardly against the force of thespring 3|. When these parts move upwardly to a position where the lower collar 13 engages the upper collar of the motion limiting means 13, the pressure operated reliefV valve 35 opens because the upper spring |03 included therein is adjusted so that the reduction in pressure in the passage 33` acting on the piston valve 31, of the pressure operated relief 'valve 33, is then sufiicient to cause it to move upwardlyl so that the ports |1 lll in the iiow of fluid from the sump valve housing 3|. This allows a sudden to pass through the pipe |23, passage |21 Ain the housing I, ports ||3 passage 53 interconnecting the compensating PS- tons to cause the pressure therein to be increased suddenly to a value equal to that in the sump,

tially check further upward movement of the valve sleeve and 'compensating receiving piston which thenfallows the spring. to start moving .the valve sleeve and compensating actuating piston downwardly in follow up relation with respect" to theV pilot valve, which is now being moved downwardly. `The pilot valve is being moved downwardly by inward movement of the centrifugalweights in 4response to the decrease in` speed of the prime mover due to the reduction in fuel supplied thereto by ment-of the pilot valve land 23- past the port 33 of the valvesleeve momentarily stops this initial downward movement of the power 'piston when the port 33 is closed by the land 23. When the power piston stops in this lower position the reduction in fuel supplied 'more than enough to compensate for the suddenv initial upward movement of the pilot valve caused to the prime mover is of the piston valve registers with the port the initial downwardmovement of the power piston. Downward moveby the sudden initial outward movement of the centrifugal weights in response to the wide and sudden reduction in the governor speed setting or decrease in load on the prime mover. As a result of the above, the centrifugal weights will then move inwardly beyond their original position to cause the pilot valve to move downwardly beyond its normal position. When the land 29 of the pilot valve is moved downwardly past the port 33 in the valve sleeve, fluid from the constant pressure flui'd source is allowed to enter the space under the power piston through pipe 36, passage 32, valve sleeve ports 3| and 33 and the passage 34 to cause the power piston to then move upwardly. This upward movementl of the power piston and also the compensating actuating piston causes downward follow up movement of the valve sleeve and compensating receiving piston by the increase in pressure in the passage 59, which is applied to the compensator receiver pistonv by this upward movement of the compensator actuating piston. -The compensator receiving piston and valve sleeve will accordingly be also moved downwardly below the normal position until the port 33 in the valve sleeve is adjacent the land 29 of the pilot valve, which is then also below the normal position, thus cutting off the fluid pressure applied to the power piston to stop upward movement thereof. The power piston will thus be finally stopped in a position below its normal position and above the position at which its initial downward movement was' stopped'. This final upward movement of the power piston and compensating actuating piston causes an increase in the fuel supplied to the prime mover just necessary to compensate for the initial reduction in fuel which, as explained, was more than enough to compensate for the sudden reductionv in governor speed setting or sudden reduction in load on the prime mover. This nal increase in the fuel causes prime mover speed will accordingly be increased to a new constant value corresponding to the change in the governor speed setting or the speed of the prime mover will be adjusted to its original constant value due to the increase in load thereon.

For a gradual and small change in either the governor speed setting or load on the prime mover the needle valve 81 may be adjusted to allow the valve sleeve 25 to follow movement of the pilot valve I5 from its normal position to cause the power piston to move to a new position such that the change in the fuel supplied is just right to an increase in the speed of the prime mover to a new lower constant value corresponding to the reduction in governor speed setting or to the same constant value of speed for the reduction in load on the prime mover. The centrifugal weights will accordingly move outwardly `in response to this final increase in speed to their normal position, moving the pilot valve upwardly to its normal position and the valve sleeve will bemoved upwardly to its normal position by the spring 8| at the same rate as the pilot valve with the port 33 in the sleeve adjacent the land 29 of the pilot valve to retain vthe power pis- -ton in the new position,since the pressure in the space 59 connecting the compensator pistons isr then relieved at the proper rate by fluid entering this space from the sump through pipe |28`passages |21 and |31, bore |33 and orifice |35 of ,I the needle valve 81, .when this valve is properly adjusted.

It will be evident for a wide and sudden in crease in the speed setting of the governor or a wide and sudden increase in the external load on the prime mover that the governor will act in the reverse manner to that described above. That is, the fuel supply to the engine will be initially increased more than enough to compensate for this change and finally decreased to compensate lor tne initial change in theffuel supply. 'I'he ca use both the pilot valve and sleeve to move back to their normal position while leaving the power piston in the new position. For gradual and small changes the collars v1i) of the motion limiting means 18 do not engage and the pressure operated relief valve does not function.

The above described governor adjusting means are readily adjustable to vary the rate and extent of movement of the power piston operating the means provided on any type of prime mover toadjust the actuating fluid supplied thereto in order to properly control the speed thereof for both gradual and small and wide and suddeny changes in load and speed demanded from the prime mover.

It has been found that the governor mechanism may be used in a similar manner to control both the supply of actuating fluid and load control means for a prime mover electric power plant such as used on Diesel electric power plants.

We claim:

vA -governor for controlling prime mover speed varying means comprising, fluid pressure actuated means for operating said means, prime mover speed responsive means, means for adjusting the speed response ofl said speed responsive means, a two element valve means for controlling movement of said fluid means, said valve means lcomprising a pilot valve element operable by said speed responsive means anda second valve element movable in follow-up relation to said pilot valve to cause movement of said fluid means, and adjustable compensating means for varying the rate and extent of follow-up movement of said second valve element with respect to said first valve element to control the rate, direction and extent of movement of said fluid means to'compensate for movement of said speed responsive means due to speed variations of the prime mover, or due to adjustment of the speed response of the speed responsive means, said adjustable compensating means comprising adjustable means for stopping the movement of said second valve element and means rfor retarding .the motion of said second valveelement, a comfluid pressure variations in said uid passage.

` IRA R. BOURLAND,

ARTHUR A. HEAVENER.