US1728042A - Emergency governing mechanism for elastic-fluid turbines and the like - Google Patents

Description

Sept. 10, 1929. R. J. CAUGHEY 1,728,042

EMERGENCY GOVERNING MECHANISM FOR ELASTIC FLUID TURBINES AND THE LIKE Filed June 24, 1927 Inventor; Reed J. Caugheg,

His Attorneg:

Patented Sept. 10, 1929.

UNITED! STATES PATENT OFFICE.

REED J. CAUGHEY, or SCHENECTAZDY, NEW YonK, nssIe-Non To GENERAL'ELEGTRIG coMrAnY, A CORPORATION or new YORK. v

nmnnenncv GOVERNING MECHANISM non nrnsrrc-rnnrb 'rneernnsjeivn THE LIKE.

Application filed June 24,

The present invention relates to governing mechanisms for elastic fluid turbines or similar machines which governing mechanisms are utilized to effect a shutting off of the supply of actuating fluid to themachine in case of excessive speed. The invention relates especially to governing mechanisms com-; prising aneccentric spring-restrained weight member carried bythe shaft and a trip finger which functions normally to hold the automatically closing emergency valve open, the arrangement being such that when the speed or" the turbine or similar machine exceedsa predetermined high .value theeccentrically- 1 mounted weight member movesoutward under the action of centrifugal force to engage the trip finger thereby releasing the emergency valve and permittingit to close.

The object of the invention is to provide 2 an improved construction andarrangement whereby a governingmechanism of this type may be tested without overspeeding the machine or without disturbing the initial setting of the emergency governor, and for a consideration of whatI believe to be novel and my invention attention is directed to the accompanying description and the claims appended thereto;

In the drawing,-Fig. 1 is a sectional view of a governing mechanism embodying the invention; Fig. 2 is a detail view partly in sectionshowing the mechanism of Fig; 1 assembled on a turbine, and Fig. 3 is a plan'view of the emergency governor.

Referring to the drawing, 1 indicates an elastic fluid turbine of anysuitable type, the turbine being provided with a fluid chest 2 to which elastic fluid is supplied by a conduit 3. I In conduit 3 is a combined trip and throttle valve 4:,a well-known type being in-' dicated diagrammatically. Valve 4 is biased toward closed positionbut is held normally open by a catch controlled by link 5 which is connected by a rod6to a bell cranlelever 7.

Gonneetedtothe free end otfhelieranir'lever 192'?! Serial No; 201,248;

7 is a plunger rod which extends down through a housing 9 to apoint in'proximity to a pivoted trip finger 10. Trip finger 10 is provided with a fiat surface "11' uponwhich the lowerend of plunger rod 8 normally rests."

Fastened on rod Bis a collar l2and surroundmg rod 6 is a spring 13 whichengages collar 12 at one end and a fixed'abutment 14 at the 1 other ends Spring, '13 acts to force plunger rod 8 downward but isnormallyheld under compression by trip finger 10 upon which the plunger rod rests as is shown in Fig.2 of

the drawing. -When tripfinger 10 ismoved on itsv pivot from beneath plunger rod 8,

with a guide pin 17Jand a guide sleeve 18.

Mounted on guide pin 17 and guide sleeve 18 j lars 19 united throughout a portion of their circumferenceby a plate 20. Diametrically opposite'plate 20.; collars '19 are, connected by a guide sleeve 21in wh'cih guide sleeve 18 slides; The outer end of'guidesleeve 21 isarranged to receive an adjustable nut 22. Arranged between adjust-able nut 22.111101 the bottom of the opening inwhich guide sleeve 18 is fastened is a governor spring 23. The tension of governor spring 23 may be ad 'justed by means of the nut22.r Guide pin 17 islocatedina guide sleeve 24 fastened be-, tween collars 19 and/on the-guide pin is a nut 25 which forms, an adjustablestop with which guide sleeve 24' engages. As viewed in Fig: 1 of the drawing. centerof the mass of the governor rin .isslightlybelowthe cen ter of rotation of'theshaft,= sothat when the shaft is rotating the governor ring tends to eat-ward against the aetioii ef spring 23. Spring 23 is adjusted so that at normal speed it holds the emegency governor ring from moving eccentrically of the shaft far enough to strike trip finger 10. In case of excess speed, however, the emergency governor will move outward sufiiciently far to strike the trip finger, thereby effecting closing of valve 4.

The general arrangement of emergency valve and trip mechanism so far described is a known one and operates in a manner well understood by those familiar with this type of apparatus. p,

As pointed out above, the object of my invention is to provide an improved arrangement whereby the emergency governing mechanism may be tested without overspeeding the machine and without disturbing the setting of the emergency governor. To this end, I provide an emergency governor spring 23 which in operation is stable or under isochronous which means thatfor every speed of the turbine shaft the governor ring assumes a definite position. I then provide means whereby trip finger 10 may be moved toward and away from the governor ring. In this connection itwill be understood that withan arrangement of this type wherein the governor spring 23 is stable, the speed at which'the emergency governing mechanism will be trippedwill'depend upon the distance between the striking surface of the governor ring and the trip finger so that by.

moving the trip finger toward the governor ring the tripping speed will bedecreased while by moving it further from the governor ring the tripping speed will be increased.

In the embodiment of the invention illustrated, housing 9 is. made in the form of a cylinder in which is located a piston 26and between the piston and the head of housing .9 is arranged a spring 27 which normally biases piston 26 toward the bottom of the easing. The outward movement of piston 26 is limited by a guide sleeve and stop 28 and the inward movement of the piston is limited by a shoulder 29. Connected to housing 9 is-a pipe 30 through which a liquid such as oil may be supplied to the housing beneath piston 26. In pipe 30 is a suitable two-way control valve 31. Ontheouter end of piston 26 is a bracket 32 upon which trip finger 10 is pivoted as is indicated at 33. It'will thus be seen that the trip fingeris carried by pis ton 26. 34L is a spring which biases trip finger 10 to the position shown in Fig. 1 wherein the flat surface 11 of the trip finger is held in engagement with the end of piston 26 and in a position to be engaged by and support the plunger rod 8.

During normal operation, valve 31 is turned toaxposition to admit fluid'under pressure through pipe 30 to the underside of piston 26. This serves to hold the piston in what may be termed its retracted position,

the piston being in engagement with the end of stop 28. As thus positioned, trip finger 10 is spaced suificiently far from the emergency governor ring that it will be engaged by it only in case the speed of the turbine exceeds apredetermined high value. When it is desired to test the emergency governing mechanism, valve 31 is turned to shut off the supply or" fluid to housing 9 and permit the fluid beneath the piston to escape. Spring 27 then forces piston 26 outward until shoulder 29 engages the bottom of housing 9. This moves trip finger 1O sufficiently close to the governor ring that it will be engaged by it and turned to release plunger 8 whereby spring 13 will force rod 6 toward the left as shown in Fig. 2 thereby releasing emergency valve 4, permitting it to close.

After the emergency governor mechanism has operated, valve 31 is turned to again admit fluid under pressure to cylinder 9, thereby moving piston 26 back to its former position. Valve 4 is then reset in the usual way.

lVith the above described arrangement, it

will be seen that the emergency governor mechanism may be tested at any time without overspeedingthe turbine, without stopping the turbine and without disturbing the initial setting of the emergency governor spring 23.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to repre sent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States, is,

1. An emergency governing mechanism comprising a spring restrained eccentrically mounted weight member which assumes positions corresponding to the speed of rotation, a trip member adapted to be engaged by said weight member, a piston upon which said trip member is mounted, a cylinder for the piston, stops in the cylinder for limiting the movement of the piston therein in each direction, a spring which biases the piston toward one of said stops, and means for supplying fluid pressure to the cylinder to move the piston into engagement with the other of said stops, whereby movement of the piston from the one position to the other may be effected for adj usting the tripping member relatively to said weight member.

2. The combination with a prime mover having a valve controlling the admission of elastic fluid thereto, of means including a trip element for holding the valve open, an emergency governor comprismg an eccentrically-mounted weight member, and a spring which tends to hold the weight mem- .ber from movement, and means whereby said trip element may be moved toward and away from the Weight member While the prime mover is running, said last-named means comprising a movable element upon which the trip element is mounted, a support for the movable element stops ,for limiting the movement of the movable element in each direction, means biasing the movable element against one of said stops, and means for moving the movable element against the action of said biasing means and into engagement With the other stop.

In Witness whereof, I have hereunto set my hand this 23d day of June, 1927.

REED J. CAUGHEY.

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