Патент USA US2116385код для вставки
>May 3, 1938. R. H. COLLINGHAM 2,116,385 ELASTIC FLUID GOVERNING MECHANISM / Filed Dec. 15, 1936 Inventor‘: Robert H. Col | in ham , by K’ Hi Attorney. PatentedMay 3, 1938 I r ' i 2,116,385 UNITED ‘STATES PATENT OF‘FHCE’ ELASTIC FLUID GOVERNING MECHANISM Robert H. Collingham, RugbyQEngla-nd, assignor _ tcGeneral Electric Company, a corporation of New York > 7 Application December 15, 1936, Serial No. 116,026 lln Great Britain December 17, 1935 ‘ 1 Claim. (Cl. 137—158) The present invention relates to elastic ?uid Theright-hand end of the leverZ?' is pivoted‘ to turbine governing mechanisms, more speci?cally a bellows 2'! and the left-hand end of the lever to the kind of governing mechanisms which con26 is connected by follow-up means including a trol the inlet valve of the turbine in response to $1 changes in the vacuum of the turbine condenser. Such arrangements are important in order to prevent excessive blowing-01f from the boilers in case link 28 and a forked member 28% to the sleeve I'I. The bellows 21 communicates with the condenser 5 ' I2 through a pipe 29. The pressure in the bel lows is counteracted by means of an adjustable spring 30. it is necessary to disconnect the turbine from the , boiler during failure of the vacuum. 10 ‘ The object of my invention is to provide an During normal vacuum condition the bellows 2'! is in its maximum depressed condition and 10 improved construction and arrangement for auto- the pilot valve head 25 of the auxiliary pilot valve matically controlling the ?ow of elastic ?uid to turbines in response to pressure changes in the is in its bottom position so that no force is exerted by oil pressure on the bottom of the sleeve I‘I. exhaust, that is, in response to changes of the The latter then is held in its bottom position by 15 vacuum in the condenser of such turbines. the action of a spring 3I. The pilot valve I6 may 15 This is accomplished in accordance with my invention by the provision of an, improved pilot be normally controlled by a speed governor 3Ia connected to the valve I6 and the motor I3 by valve arrangement for controlling the ?ow of actuating ?uid to a servo-motor for moving the admission valve. The pilot valve according to 20 my invention has an element which is controlled a follow-up lever 3")» With this arrangement an increase in speed causes downward movement in response to changes in vacuum in the con- member iii whereby communication is established denser to effect closing of the turbine inlet valve as the vacuum in the condenser drops, and vice25 versa. For a better understanding of what I believe to be novel and my invention, attention is directed to the following description and the claim appended thereto in connection with the accompanying drawing which illustrates an embodiment of a preferred arrangement of my invention. between the inlet port 20 and the conduit I5, per mitting the supply of actuating ?uid to the hy draulic motor i3 and resulting in closing move- 30 . . The arrangement shown in the drawing com- prises an elastic ?uid turbine it which has an inlet valve II for controlling the ?ow of elastic 35 fluid thereto. The exhaust of the turbine is con- densed in a condenser I2. The valve II is moved by means of a servo-motor I3 to which actuating fluid such as oil is supplied by a pilot valve I4 connected to the servo-motor I3 by a conduit I5. 40 The pilot valve M has a movable valve member I6 disposed within a sleeve or bushing I1, which latter has a number of ports I8 and is movably disposed within a cylinder or casing I9. Actuating ?uid for operating the servo-motor or motors 45 I3 is conducted to the pilot valve through port 20 and discharged therefrom through a port 2I. The sleeve I1 and the lower portion of the casing I9 form a chamber 22 to which oil or like actuating ?uid under pressure is conducted to effect 50 movement of the sleeve. The ?ow of actuating ?uid to the chamber 22 and the discharge of ?uid therefrom is controlled by an auxiliary pilot valve 23 which has a casing 24 attached to the casing I9 and a movable valve member‘ 25 with a stem 55 connected to an intermediate point of a lever 26. of the left-hand end of the ?oating lever 3Ib and consequently downward movement of the valve 20 5 ment of the turbine inlet valve II. Similarly, a drop in speed causes opening movement of the valve II. As long as the sleeve I1 is in its lower position, the governor 3Ia for normally control ling the flow of elastic ?uid to the turbine can 30 . . . effect complete opemng of the admission valve I I. If now for some reason the vacuum falls below a predetermined value ?xed by the tension of the. spring 30, the bellows is expanded and thereby causes upward or opening movement of the aux iliary pilot Valve 25 until actuating ?uid under 35 pressure is admitted to the chamber 22. This causes upward movement of the sleeve I‘I until the follow-up mechanism between the sleeve I1 and valve member 25 restores the auxiliary pilot valve to its normal neutral position. Upward movement of the sleeve I'I establishes connection between the port 20 and the conduit I5 and thus permits the ?ow of actuating ?uid to the lower part of the hydraulic cylinder I3. This e?ects upward movement of the piston of the servo motor I3, resulting in closing movement of the inlet valve I I and consequently a decreased ?ow of elastic ?uid to the turbine Iii. The closing movement of the inlet valve II is automatically effected without any change in the main gover nor setting, not shown, and the portion of the load thrown o? by the setting may be transferred to other turbines operating in parallel. If the vacuum drops further, the operation de- 40 45 50 55 2 2,116,385 scribed above is repeated until the turbine is the combination of a turbine having an inlet valve carrying such a load that any further reduction might cause dangerous heating of the low pres for controlling the ?ow of actuating ?uid thereto, sure end of the turbine. Preferably, therefore, the vacuum trip is set to operate automatically to effect shutting off of the steam supply at this load. Actuating ?uid leaking along the outer surface of the sleeve is discharged through an opening 33 into a channel 34. 10 With my above invention I have accomplished an improved construction and arrangement of governing mechanism for elastic ?uid turbines, especially useful in connection with arrangements where a'plurality of turbo-alternators are con nected to the same electrical system. My im proved arrangement permits the reduction of the load of any particular turbo-alternator with in ?nite ?neness of graduation. What I claim as new and desire to secure by 20 Letters Patent of the United States is: An elastic ?uid turbine arrangement including a condenser for condensing elastic ?uid exhausted from the turbine, and means for positioning the inlet valve in response to changes in vacuum in 5 the condenser, said means comprising a servo motor for moving the valve, a pilot valve for the servo-motor, the pilot valve including a valve member, a sleeve forming ports and surrounding the valve member and a stationary casing sur 10 rounding the sleeve, the sleeve and the stationary casing forming a chamber, means for controlling the ?ow of actuating ?uid to the chamber in response to changes in vacuum in the condenser to e?ect movement of the sleeve, said means com prising an auxiliary pilot valve, a device respon sive to changes in vacuum for moving the aux iliary pilot valve and a follow-up mechanism con nected between the auxiliary pilot valve and the sleeve. 15 " 20 ROBERT H. COLLINGHAM.