US1575159A - Governor - Google Patents

Description

March 2,1925. 5 1,515,159 .5 w. B. FLANDEVRS- GOVERNOR Filed Dec. 5, 1924 3 Sheets-Sheet 1 Q 8,, III 1 w o 8 5 5 5 (U M f g 1 l 2 g Q E Wfiflander; INVENTOR WITNESSES: BY 9? ATTORNEY March 2, 1926.

w. B. FLANDERS GOVERNOR A s. Sheets-Sheet 2f Filed Dec. 5, 1924 I III I I IV IIII'I EEEWSZZZSZZQ/n WITH 5 s; w.

ATTORNEY WITNESSE Mmh 2,1926. 1,515,159

W. B. FLANDERS GOVERNOR Filed Dec. 3 1924 3 Sheets-Sheet a .Bflanders INVENTOR ATTORNEY Patented Mar. 2, 1926 UNITED STATES PATENT OFFICE.

WARREN B. FLANDERS, 0F PHILADELPHIA, PENNSYLVANIA, ASSIGNOR T0 WEST- INGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OFIENN- SYLVANIA.

GOVERNOR.

Application filed December 3, 1924. Serial No. 753,596. 1

To all whom it may concern:

Be it known that I, IVARREN B. FLANDERS, a citizen of the United States, anda resident of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented a new and useful Improvement in Governors, of which the following is a specification. I

My invention relates to variable fluid pressure operated governing apparatus such as may be used for a prime mover and it has for its object to provide, in apparatus of the character designated, means, in addition to the variable fluid-governing pressure, which shall operate upon the attainn'ient of a predetermined speed of the prime mover, to cause the governing apparatus to close off the supply of motive fluid thereto.

A further object of my invention is to provide automatic means for limiting the power produced by the unit governed.

Armar-atus made in accordance with my invention is illustrated in the accompanying drawing in which: Fig. 1 is a view partly in section of an elastic-fluid turbine having my improved governing apparatus applied thereto: Fig. 2 is a vertical sectional view of the governing apparatus: Fig. 3 is a sectional view taken along the line III-III of Fig. 2: and Fig. 1 is a view partly in section of an auto-stop governor used in connection with my invention.

In the application of Henry F. Schmidt, Serial No. 604,033, filed November 29,1922, and in the application of John S. Myers, Serial No. 662,316, filedSeptember 12, 1923,

both assigned to the Vestinghouse Electric & Manufacturing Company, there is shown and described governing apparatus to which my invention is particularly applicable. This apparatus embodies an impeller pump for dcveloping fluid pressure varying as a. function of the speed of the machine governed. an element movable in response to variations in the fluid pressure, and means for transmitting. movementsof the element to control the machine governed. In such apparatus the force of the governing fluid pressure acts to move the admission valve, or other controlling means of the machine governed, in a closing direction, while a spring, associated with the element is em ployed opposing the governing fiuid pressure and acting to move the admission valve in an opening direction.

Vhile apparatus so constructed has proved very dependable in operation, instances may occur where the pressure developed by the impeller pump fails to increase in proper proportion to the speed of the machine governed, due to heavy leakage from the oil pipes or passages, or to other causes. \Vhere such instances occur, the speed of the machine governed increases beyond safe limits. It is very desirable therefore to provide some means, automatically operative, which shall be effective to move theadmission valve or other control means, of the machine governed in a closing direction upon the attainment of a predetermined speed by the prime moven In accordance with my invention, I provide a governing apparatus operated as above described and also employ a well known form of auto-stop governor. The auto-stop governor is set to. trip upon the attainment of a predeterminedspeed by the prime mover. Between the auto-stop governor and the fluid pressure operated governor is a motor operable upon tripping of the autostop governor, and which acts as an aid to the governing fluid pressure in mov-- ing the pressure operated element in a direction for closing down the prime mover. I also provide a power limit device, associated with the beforementioned motor, which operates to prevent movement of the pressure operated element beyond a predetermined limit, in a direction for admitting power to the machine governed.

Referring now to the drawings for a detailed description of my invention, I show in Fig. 1, at ,10, a steaui turbine having an admission valve 11 controlled by my improved governing apparatus at A part of the governorhousing is shown broken away for better illustration. Fluid under pressure varying as a functionof the speed of the turbine 10 for actuating the governing apparatus is developed by a pump 13 driven by shaft 14 of the turbine 10.

The governing apparatus at 12, Fig. 2,

comprises a housing 16, which is provided with an operating cylinder 17, anda supply chamber 18,, the latter; being connected to the discharge of the impeller of the centrifugal pump 13. An operating piston 19 is arranged within the cylinder 17. The upper face 21 of the piston 19 is adapted to be actuated by fluid under pressure, while QTY ' by the governing fluid pressure.

portion the wer face of the piston member is at all times open to the exhaust through a port and conduit which permits governing fluid passing therethrough to drain' through to the turbine bearings The ope 'ating piston 19 is provided with an upper stem portion 23 and a lower stem The upper stem portion is connected to a rod 26 which actuates a lever 27 which is, in turn, connected to a stem 28 of the admission valve 11. The lower stem 24 of the operating piston ll) extends downwardlyinto the supply chant ber 18 and is at all times subjected to the fluid pressure developed by the pump 13. lhe operating cylinder 17 is provided with an upper head 29 and a lower head 31 through which the stem portions 23 and A extend, making a fluid-tight lit therewith. The operating piston 19 is provided with a series of upper ports and a series of lower ports 33 for admitting and ezdiansting fluid under pressure to and from the upper face of the operating piston. The operating piston 19 is made hollow and has disposed therein a pilot valve 3% of the piston type. The pilot valve 3% is provided with ports 36 which, in registry with the ports 32, permit fluid under pressure to pass to the upper side of the piston 19. A constricted portion 37 ot the pilot valve 3i, when in registry with the ports 3-2, permits fluid under pressure to pass from the upper side of the piston 1.) to the lower side thereof through ports 33 and thence outwardly to the exhaust. An annular shoulder 38 on the pilot valve St, between the ports 36 and the constricted portion 37, serves to cover the ports 32 at times, preventing fluid under pressure from passing to the upper face 21 ot' the piston 19 or to pass therefrom to the exhaust. The pilot valve 34 is provided at its upper end with a cap member 39 which serves to close the upper end thereof. The upper stem portion 23 ot' the operating piston 19 is bored out, providing an enlarged bore ll which permits the cap 'urember $3!) to move treely therein. Secured to the cap member 39 by a suitable spring anchor is a relatively heavy spring 42 which is secured. at its lower end by suitable means to the lower stem portion 24 ot the operating iiston 19. The function of the spring is to bias the pilot valve ill toward its lowest position with respect. to the operating piston 19 in opposition to; the force exerted i It rela tively light spriu'g elil is also secured, at it=-: upper end, to thocap member 3-! and at its lower end o a stationarymember. The spring 43 serves as a scale spring determirr ing the range of movement; of the pilot valve ill and operatingpiston 19 per unit oi change in governing fluid pressure.

In operation. fluid under a pressure varym with the speed of the turbine- 10 is developed by the pump 13 and delivered to the supply chamber 18 where itacts across the-area ot the lower stem; portion 2 1 of the operating piston 19, tending to force it upwardly. The area ,or" the lower stem portion 24 is made less than the area of the upper taco 21 of the operating piston 19. So long as the governing fluid pressure is less than the load on the springs 42 and ll), ports 36 and 32 are in registry and the fluid pressure acting against the greater area ot the face 21 oi the operating piston 11? holds it to its lowermost position with the admission valve ll open. As the speed of the turbine 10 increases, governing fluid pressure increases and acts against the pilot valve i-l-l through the cap member 3-9, graduallv overcoming the force exerted by the lugs and l-S, lorcing the pilot valve i'l-l upwardly relative to the operating. piston 19. As the pilot valve 3% starts to move upwardly, the annular shoulder 38 comes in re str v with the ports 32 cut-rapping fluid above the taco 21, the operating piston 1:) remaining stationary until. a further increase in governing fluid pressure occurs.

Assuming that the pressure or" fluid within the supply chamber 18 further increases, due to an increase in speed of the turbine 10, fluid under pressure, acting upon the cap 39 of the pilot valve til-l, overcomes the force exerted by the springs and and forces the pilot valve 3 1 upwardly, placing the coustricted portion 37 in registry with the up per ports 32, permitting fluid entrapped above the face 21 of the operating piston 19 to pass to the lower side thereof and thence to the exhaust, whereupon fluid under pressure acting against the area of the lower stem portion 2a of the operating piston 19 forces the operating piston upwardly and the admission valve 11 in a closing direction. In starting the upward movement of the pilot valve the governing fluid pressure necessary is that to overcome the combined force of the springs 42 and 43. As soon. however, as the constricted portion 37 registers with the ports 32 the operating piston 19 begins to follow the pilotvalve 34 taking the lower end of the spring -12 with it and the spring 42 is not stretched any further. As the pilot valve continues to move upwardly it further stretches the coniparatively light spring -l3, placing an increasing load upon it until the shoulder 38 is again broughtin registry with the-ports 32 preventing turther passage of fluid from the upper side of the operating piston 19 and preventing its further upward i'novemei, t

It can thus be seen that movements of the pilot valve 34 and the operating piston 19 are determiiurd by the scale of the small spring lil after the piston 19 has st rted to move. The pilot valve ill: and operating piston 15} remain in the equilibrium position described until a further change in governing fluid pressure occurs. 7

Assuming that the speed of the turbine drops, causing a decrease in governing fluid pressure in the supply chamber 18, the governor springs 42 and 43 cause the pilot valve 34 to move downwardly, placing the ports 36 thereof in registry with the ports 32 of the operating piston 19 admitting fluid under pressure to the active face 21 of the operating piston 19, forcing it downwardly as previously described.

Upon an upward movement of the pilot valve 32, influenced by an increase in fluid pressure, or a downward movement thereof caused by a drop in fluid pressure and the force exerted by the governing springs 42 and 43, said movements continue until the force exerted by the governing fluid pressure is equal to the force exerted by the governing springs whereupon the annular shoulder 38 of the pilot valve 34 covers the upper ports 32 of the operatingpiston 19, stopping its movement. The pilot valve and the operating piston 19 will remain-in this position until a further change in governing-fluid pressure takes place, all as described in the beforementioned applications of Henry F. Schmidt and John S. Myers.

In order to limit'movements of the pilot valve 34 and the operating piston 19 when moving the admission valve 11 in an opening direction, and, in case of overspeeding of the turbine 10, to close the admission valve 11, I provide a lever 46 fulcrumed at 47 in a suitable support formed on the housing 16; One endv of the lever 46 extends through the housing 16 as shown in Fig. 3 and is provided with a lug 48 whichextends through a; suitable slot 49 in the upper end of the stem portion 23 of the operating piston 19. The lug 48 is positioned below the cap member 39 of the pilot valve 34, as shown by the dotted lines in Fig. 2, and is adapted to engage with said cap member upon downward movement of the pilot valve 34. The lug 4S and slot 49 are also so arranged that upon extreme movements of the lever 46, with the lug 48 moving in an upward direction, and when there is a failure of governing fluid pressure, the lug 48 engages the upward part of the slot 49 and moves the operating piston 19 upwardly in a manner more particularly described latter.

With this arrangement the pilot valve 34 and piston 19 maymovefreely in an upward direction, as upon increases in fluid pressure induced by .increases in speed, for closing the admission valve 11. As the pilot valve 34 moves downwardly, however, followed by the operating piston 19, moving the admission valve 11 in anopening direction, th'e'lug 48 engages the cap 39 of the pilot valve 34- carrying the inner end of the level- 46 downwardlyand causing the outer end to move in an upward direction. Upward movement of the outer arm of the lever 46 is limited by an adjustable stop member 51, said member having a fixed support as from the cap number 29 as shown. It will be apparent that upon downward movement of the pilot valve 34, and with the lug 48 engaged with the cap member 39, as soon as the outer end of the lever 46 engages with the stop member 51 further movement of the pilot valve 34 and -ae operating piston 19 in a downward direction is arrested. Thus, the opening of the admission valve 11 and the power developed by the unit governed may be limited to any desired extent. The stop 51 may be set in any desired position, at any time and may be operated manually as indicated in Fig. 2, or may be operated from a distance as by means of a reversing motor 51 and suitable gearing as shown in Fi 1.

I also provide means for securing a positive closure of the admission valve 11 in case the turbine 10 should overspeed. To

this end I show at a cylinder having disposed therein a piston The piston 53 has a stem portion 54 extending through the upper end of the cylinder 52 and connected to the outer end of the lever 46 by a lost motion connection 56. By this means, during normal. movements of the pilot valve 34 and of the operating piston 19, there is no interference by the piston 53 with said movements. The piston 53 is provided with a restricted passage 5( connecting the upper face tothe lower face thereof or otherwise so arranged as to permit a restricted flow of fluid thereby It will be seen from the drawing that the effective area of the upper face of the piston 53 is the area of said piston less the area of the stem portion 54, while the total area of the under face of the piston 53 is effective. The upper end of the cylinder 52 is connected by a conduit 58 to the motive fluid supply pipe of the turbine 10 so that fluid under pressure is at all times acting against the upper face of the piston 53 and is free to pass by way of the restricted passage 57 to the lower end of the cylinder F2. The lower end of the cylinder 52 is connected by a conduit 59 to an autostop governing device to he described later which controls the flow of fluid from the lower end of said cylinder.

\Vith the conduit 59 closed, fluid under pressure on top of the piston 53 passes through the restricted passage 57 and acting against the greater area of the under face of the piston 53 forces it to its uppermost position where it remains until the pressure beneath the piston is relieved. lVhen the pressure beneath the piston 53 is relieved, the pressure acting against the upper f ce xthreet forces it- ,clowa ardly whereupon the lost motion connection 56 is engaged, the outer end of the lever a6 is forced downwardly by the force exerted by the motive fluid on top of the piston 53 and the inner end of the lever 16 is forced upwardly. Upon upward movement of the inner end of the lever to, the lug 48 engages the cap 39 of the pilot valve 34 forcing the pilot valve 3% upwardly, followed by the operating piston 19, as already described, and closing the admission valve 11. If, for any i ason, fluid under pressure supplied from the governor 12 has failed, the lug eiS engages the upper end of the slot -19 and forces the piston 19 upwardly, thus ell'eet ing a closure of the admission valve 11 with or without governing-fluid pressure.

In Figs. 1 and a, I show a wellknown form of auto-stop governing mechanism for controlling the pressure beneath the piston T he auto-stop governing mechanism comprises a tripping weight 61 disposed within a diametral recess of the shaft 1st and normally held in position by a spring 62. Within a IDlBCliEtElil'liDGtl range of speed, the tripping weight 61 is inoperative. Upon the attainment of a predetermined speed, however, the tripping weight 61 protrudes from the shaft 1st striking a member 63 secured to a shaft 64, which is in turn supported from a housing-65, surrounding the shaft 1%. I show at 66 a valve member which is normally hold on its seat by a trip lever 67 pivoted at (38 on the housing 65. The trip lever 67 is normally held in position by a latch 69. secured to the shaft 6%, and controlled by the tripping member 63. In order that the valve (35, when seated, may be held on its seat bv a positive pressure, a spring 71 is provided in compression between a stem 72 which bears upon the stem of the valve 66 and an adjustable abutment 73 carried by the trip lever 67.

The valve 66 serves to close the conduit 59 leading to the underside of the piston 53, the conduit 59 being connected to the underside of the valve (36. lVhen the valve 66 is unseated, pressure within the conduit 59 and beneath the piston 53 is free to pass to the atmosphere through a port 'lhe operation of apparatus made in accordance with my invention will be apparent. During normal speeds of the turbine 10 and normal governing pressure the pilot valve 31 and o ierating piston 19 are free in their movements to control. the position of the admission valve 11. Should the turbine speed drop a predetermined amount, causing a reduction in the pressure developed by the pump 13, the pilot valve followed by the operating piston 19 moves downwardly until the cap 39 of the pilot vaive 25% engages the lug 48 of the lever 4:6 and the outer end of the lever 46 is arrested init s upward movement by the stop 51, The

stop 51 pevents further movements of the pilot valve 34 and operating piston 19 in a downward direction and thus prevents a further opening of the admission valve 11, limiting the power developed by the turbine 10.

If for any reason the turbine 10 should overspeed, whether from failure of governing pressure or otherwise, the weight 61 of the auto-stop governor protrudes from the shaft 14, striking the member 63, and disengaging the latch 69 which holds the trip lever 67 in position and the valve 66 closed. Pressure within the conduit 59 and beneath the piston is then free to raise the valve 66 and pass outwardly to the atn'iosphere through the ports 74. Upon relief of pressure beneath the piston 53, it is forced downwardly by the pressure of motive fluid above it in a manner already described. Upon downward movement of the piston 53 the outer end of the lever a6 is pulled downwardly through the lost motion device 56 causing the inner end of the lever 16 to move upwardly, whereupon the lug es of the lever 16 engages the cap 39 of thepilot valve forcing the pilot valve upwardly. Upward movement of the pilot valve 3% causes governing fluid to be exhausted from above the operating piston 19, whereupon the governing fluid under pressure acting against the operating piston 19 and the pilot valve 3% causes an upward movement thereof, closing the admission valve 11 in a manner already described. If for any reason, there has been a failure of governing-fluid pressure the lug a8 engages with the upper por tion of the slot 49 in the piston 19 forcing the piston 19 upwardly and closing the admission valve 11 by the. force of the motive fiuid acting against the upper face of the piston 53.

From the foregoing, it will be apparent that I have invented an improved governing apparatus efiective to limit the power produced by the unit governed and also effective to positively close off the supply of energy thereto in case of overspeeding.

lVhile I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended 'claims.

.Vhat I claim is:

1. In a. variable fluid pressure operated governing apparatus for an elastic fluid turbine having an admission valve, the com bination of an element movable in response to increases in the variable fluid pressure and ef et e for m ing the dm ssion al in a closing direction, resilient means associated wlth the element and opposing the governing fluid pressure for eflecting open- 2. In a fluid-pressure actuated governing apparatus for a prime mover, the combination of means for developing fluid pressure varying as a function of the speed of the prime mover, a pilot valve movable in response to variations in the fluid pressure, an operating piston controlled by the pilot valve and following its movements, and additional means operable upon a predetermined speed of the prime mover for effecting a movement of the pilot valve and the piston in the direction of movement caused by increases in fluid pressure.

3. In a fluid-pressure actuated governing apparatus for a prime mover having an admission valve, the combination of means for developing fluid pressure varying as a function of the speed of the prime mover, a pilot valve movable in response to variations in fluid pressure, anoperating piston controlled by the pilot valve and following its movements, said operating piston contro'lling the position of the admission valve, and means in addition to the variable fluid pressure operable upon a predetermined speed of the ,prime mover for moving the pilot valve and the operating piston in a direction for closing the admission valve.

4. In a fluidepressure actuated governing apparatus for a prime mover having an admission valve the combination of means for developing fluid pressure varying as a function of the speed of the prime mover, a pilot valve movable in response to variations in fluid pressure, an operating piston controlled by the pilot valve and following its movements, said operating piston controlling the position of the admission valve, a lever having means at one end adapted to engage with the pilot valve and also adapted upon extreme movements to engage with the operating piston, a fluid motor normally inoperative for actuating the lever so as to engage and move the pilot valve\and the operating piston to close the admission-valve, and tripping means operable upon a predetermined" speed of the prime mover for rendering the fluid motor operative.

5. In a fluid-pressure actuating governing apparatus for a prime mover having an admission valve, the combination of means for developing fluid pressure varying as a function of the speed of the prime mover, a pilot valve movable in response to variations in fluid pressure, an operating piston controlled by the pilot valve and following its movements, said operating pistencontrolling the position of the admission valve, a lever having means at one end adapted to engage with the pilot valve and also adapted upon extreme movements to engage with the operating piston, a member adapted to engage with the lever and limit movements of the pilot valve when moving in a direction for opening the admission valve, a fluid motor normally inoperative for actuating the lever so as to engage and move the pilot valve and the operating piston to close the admission valve, and tripping means operable upon a predetermined speed of the prime mover for rendering the fluid motor operative.

In testimony whereof, I have hereunto subscribed my name this twenty-first day of of November 1924:.

WARREN B. FLANDERS.

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