US1756850A - Emergency governing mechanism for elastic-fluid turbines and the like - Google Patents

Description

April 29, 1930. R J AUGHEIY 1,756,850

' EMERGENCY GOVERNING MECHANISM FOR ELASTIC I FLUl TURBINES AND THE LIKE led June 24, 1927 Inventor: Reed Cougheg,

His Attorney.

Patented Apr. 29, 1930 v UNITED STATES REED J. OAUGKE Y, SCHENECTADY, NEW Y03:1 ,.ASIGNORTO GEIIEBAL WHO COMPANY, A COBPOBATIGF OF NEW YORK I PATENT oFFIc maneuver aovnnnme nncmmsm r013. ELASTIG-FLUIIl) TUBBDIIlS min m m Application filed. June 94,

The present invention relates to governing mechanisms for elastic fluid turbines or similar machines which governing mechanisms are utilized to effect the shutting off of the supply of actuating fluid to the machine in case of excessive speed. The invention relates especially to governing mechanisms comprising an eccentrically mounted spring-restrained wei ht member carried by the shaft and a trip finger which functions normally to hold the automatically closed emergency valve open, the arrangement being such that when the speed of the turbine or similar machine exceeds a predetermined high value, the eccentrically mounted weight member flies out and engages the trip finger thereby releasing the emergency valve and permitting it to close. I

The object of the invention is to provide an improved construction and arrangement whereby a governing mechanism of this type may be tested while the machine is running without overspeeding the machine and without disturbing the initial setting of the emergency governor, and for a consideration of what I 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 view partly in section of an elastic fluid turbine provided with an emergency governing mechanism embodying the invention; Fig. 2 is a transverse sectional view through the emergency governor; Fig. 3 is a longitudinal sectional view of the emer ency governor; Fig. 4 is a top plan view 0 the emergency governor shown in Fig. 2, and Figs. 5 and 6 are detall vlews similar to Figs. 2 and 3, of a modification. I

Referring to the drawing, 1 indicates an elastic fluid turbine of any suitable type, the turbine being provided with a fluid chest 2 to which elastic fluid is supplied by conduit 3. In conduit 3 is a combined trip and throttle valve 4, a well known type being indicated diagrammatically. Valve4 is biased toward closed position but is held open normally by a catch controlled b a linkv 5 which is connected by a rod 6 to hell crank lever 7 Gonnected to the free end of bell crank lever 7 1927. mm No. 201,249.

is a plunger rod 8which extends down through the plunger rod rests as is shown in Fig. 1 of the drawing. When the trip finger is moved on its pivot from beneath plunger rod 8 sprin 13 forces the plunger rod downwar thereby turning the bell crank lever 7 and through rod 6 and link 5 releasing the catch for valve 4. Valve 4 then closes automatically.

The emergency valve mechanism above de scribed is a known arrangement and'one in common use in connection with elastic fluid turbines. It is shown more or less diagrammatically and is to be taken as typical of any suitable arrangement for effecting closing of an emergency valve.

Referringnow more particularly to Figs.- 2, 3 and 4, mounted on the shaft of the turbine, which shaft is indicated at 14, is an emergency governor in the form of a rin 15 comprising two annular walls 16 and 17 eld.

in spaced relation to" each other by a wall 18 suitably connected thereto and by a c linder 19 which is fastened to walls 16 an 17 by means of flanges20 which. are riveted to the walls. Ring 15, which may be termed an outer ring, 1s mounted on an inner ring 21 which in turn is fixed directly on shaft 14, the connection between rings 15 and 21 being such that when a redetermined speed is reached, ring 15 will be moved transversely relatively to ring 21 by centrifugal force and strike the end of trip finger 10 to trip the emergency governor valvemechanism and permit the valve to close automatically. This cylinder head 27 having threaded engagement with cylinder 19 so that b screwing the head into and out of the cylin er the tension of the spring can be adjusted. 28 is a guide member for ring 15, the same being in the form of a sleeve which surrounds spring 26 with one end fixed in socket 25 and the other having sliding engagement with cylinder 19. The lower side of ring as viewed in Fig. 2 is heavier than the other side so that when the shaft is rotating ring 15 tends to move transversely of the shaft. In other Words, the center of mass of ring 15 as viewed in Fig- 2 is located below its geometrical center orthe center about which it rotates. It is held from movement normally by spring 26 which tends to hold ring 15 1n the position shown in Fig. 2 with the end of block 24 against an adjustable stop but 29. -After a predetermined speed is reached, the centrifugal force exerted on ring 15 will be suflicient to overcome spring 26 and move ring 15 transversely of the shaft so it will engage trip finger 10 and effect closing of the emergency valve. In-ordinary practice, the tension of spring 26 will be adjusted so the emer ency mechanism will operate at a speed a pre etermined amount above normal speed. The characteristic of spring 26 is such that it is over-isochronousor unstable so that ring 15 does not begin. to move until a certain speed is .;reached but when the ring'does start it 1es out tov its extreme position. Now, in order to be able to test the emergency governing mechanism at any time without overspeeding the turbine, I provide a means whereby while the machine is running the tension of spring 26 can be decreased an amount such that the centrifugal force acting on the emergency governor at normal speed is suificient to effect movement of the I emergency governor ring 15.

. In the arrangement shown in Figs. 1 to 4,

carried by a stem 31 which extends through.

a. radial opening 32 in shaft 14. Opening'32 communicates with an axial opening 33 in the end of shaft 14 and in such axial opening is a rod 34 provided with a beveled surface 35 upon which the lower end of stem 31 rests. Rod 34 rotates with the shaft and its outer endis arranged in a suitable bearing housing 36 carriedon a stationary support 37 and on which it may slide. Connected to housing 36 by a link 38 is a hand lever 39 by means of which the housing and rod 34 ma be moved axially relatively to shaft 14. od 34 has two ositions relatively to shaft 14, one of whie may be termed the in position (which is t e osition shown in F i 3 of the drawing) and the other of whici may be termed out position. When rod 34 is in the in position, stem 31 is held in raised position by surface '35 thereby increasing the compression of spring 36. This in the nor- 1,7ae,euo

mal or running position of the emergenc governor. When rod 34 is moved to its out position, it will be seen that the beveled sur face 35 moves under stem 3l permitting the stem to move inward toward the center of the shaft, thereby decreasing the compression of spring 26.

In the use of the invention, rod 34 is set in its in position as shown in Fig. 3 and the compression of spring 26 is adjusted by means of nut 27 for the desired emergency tripping speed. When the turbine is running and it is desired to test theemergency governing mechanism, it is necessary -mere 131 to move rod 34 to its out position by means of hand lever 37 thereby decreasing the compression of spring 26, whereupon the emergency governor will operate to effect tripping of the emergency valve mechanism. After the test has been completed the emergency governor is restored to its former condition by moving rod 34 back to its in position.

lVith this arrangement, it will be seen that the emergency governor can be tested readily without overspeeding the turbine, without its being necessary to stop the turbine, and without permanently disrupting the initial setting of the emergency governor spring.

In Figs. 5 and 6, I have shown a modification wherein the emergency governor spring 26 corresponding to spring 26 of Figs. 1 to 4 inclusive, is supported on a piston 42 which moves in a cylinder 43. The outer end of turbine shaft 14 is carried in a bean ing 44. Connected to bearing 44 is a wall 45 which provides a chamber 46 which chamber is connected to cylinder 43 beneath piston 42 by an axially-extending passage 47 and a radially-extending passage 48 formed in shaft 14. Connected to chamber 46 is a pipe 49 in which is arranged a suitable twoway valve 50 by means of which a fluid under pressure, such as oil, may be supplied to chamer 46 or discharged therefrom. Outward movement of piston 42 and cylinder 43 is limited by means of the annular stop shoulder 51.

In normal operation of the emergency governor valve 50 is set to supply fluid under pressure through pipe 49 to chamber 46 from whence it flows to the underside of the piston 42 whereby piston 42 is held in its out position as defined by stop 51 and as is shown in Fig. 5 of the drawing. Now, if it is desired to test the emergency governor, valve 50 is turned to shut off the supply of fluid to cyl-- inder 43 and permit the fluid in the cylinder to escape. Piston 42 is then moved inwardly by spring 26 thus decreasing somewhat the compression of spring 26 whereupon the emergency governor will operate after the manner already described in connection with Figs. 1 to 4 inclusive, to effect closing of theemergency valve. After the mechanism has been tested, valve 50 is turned to again admit fluid under pressure beneath piston42 there by {moving it outward against stop 51 and compressing spring 26 to its former value.

In connection with each of the arrangements "illustrated, it will be seen that means are provided for-setting initially the emergency governor so that the emergency governor will operate at the desired overspeed and that in connection therewith an independent means is provided whereby the setting of the emergency governor spring may be changed by a predetermined amount to permit of testing of the mechanism after which the spring may be restored to its former initial setting. Thus the initial setting of the emergency governor is not disturbed.

In accordance with the provisions of the Patent Statutes, I have described the principle of operation of my invention, together with. the a paratus which I now consider to represent 51o best embodiment of my invention, 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. The combination with a shaft, of an emergency governor comprising an eccentrically mounted weight, a radially extending spring which normally holds the weight from movement, a movable support for the inner end of such spring, said support normally holding the spring under a predetermined compression, and means for effecting movement of said support to decrease the compression of said spring whereby the governor may operate under the action of centrifugal force at a lower speed.

2. The combination with a shaft and an emergency governor thereon com rising an eccentrically mounted weight mem er, a radially extending spring which opposes movement of the weight member, and means for cally mounted weight, a spring which opposes movement of said Weight under the action of centrifugal force, a support for the spring which support is independent of the weight, and means for eflectlng movement of said support to decrease the compression of the spring whereby the governor may be operated under the action of centrifugal force at a lower speed.

4. The combination with a shaft and an emergency governor thereon comprising an eccentrically mounted weight member, a spring normally under compression which opposes movement of the weight member and means for adjusting the setting of the governor, of means independent of said weight member and operable while theshaft is rotating for effecting a decrease in the compression of said spring whereby the emergency governor may be caused to operate under the action of-centrifugal force at a speed lower than that for which it is set by said first named means.

5. The combination with a shaft, of an emergency governor comprising an annular eccentrically mounted weight member which surrounds the shaft, a support which is independent of the weight member, a radially extending spring located between the weight member and the support which opposes movement of the weight member under the action of centrifugal force, and means for effecting movement of said support while the shaft is rotating for changing the setting of said spring whereby the emergency governor may be operated under the action of centrifugal force at a lower speed.

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

REED J. CAUGHEY.

adjusting the spring at its radially outer end for setting the governor, of a support for the radially inner end of said spring, said support being independent of the weight member and having a radially inner and a radially outer position, said support being normal in its radially outer position, and means for moving the support from its radially outer position to its radially inner position to change the setting of the s ring, whereby the emergency governor may e operated under the action of centrifugal force at a lower speed without changing the setting of said first named means.

3. In combination, a prime mover, means controlling the flow of operating fluid thereto, an emergency governor operated by centrifugal force for effecting the actuation of said means when the speed of the prime mover reaches a predetermined high value, said emergency governor comprising an eccentri-

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