US1774997A - Elastic-fluid turbine and valve structure for use therewith - Google Patents

Description

J. SCHMIDT Sept. 2, 1930.

ELASTIC FLUID TURBINE AND VALVE STRUCTURE FOR USE THEREWITH Filed Sept. 25, 1929 Patented Sept. 2, 1930 UNHTED STATES.

PATENT FFIQE JOHANNES SCHMIDT, OF BERLIN-FRIEDENAU, GERMANY, ASSIGNOR 'IO GENERAL ELEG- TRIG COMPANY, A CORPORATION OF NEW YORK ELASTIC-FLUID TURBINE AND VALVE STRUCTURE FOR USE THEREWITH Application filed September 25, 1929, Serial No. 395,175, and in Germany October 4, 1928.

The present invention relates to elastic fluid turbines and valve structures for use therewith, and especially to installations wherein a driven machine is connected to an elastic fluid turbine and an electric motor, the machine being driven normally by the electric motor and being driven by the turbine only in case the motor fails. Such in.- stallations are termed usually three-unit sets. In connection with such sets, it is known to provide in the elastic fluid admission conduit for the turbine a quick opening valve, which is normally held closed, and which is opened in case the speed of the set falls below a predetermined low value, and a separate quick closing valve which is normally held open, and which is closed incase the speed of the turbine exceeds a predetermined high value. The object of the present invention is to provide an improved construction and arrange ment wherein a single valve performs the function of both a quick opening and quick closing valve.

For a consideration of which I believe to be novel in my invention, attention is directed to the following specification and the claims appended thereto.

In the drawing, Fig. 1 is a diagrammatic view partly in section of a three-unit set equipped with a valve structure embodying the invention, and Fig. 2 is a vertical sectional "iew of the operating part of the valve structure.

Referring to the drawing, 1 indicates an elastic fluid turbine having an admission conduit 2 and an exhaust conduit 3, and 4 indicates an electric motor which receives electrical energy from any suitable source. Turbine .l and motor 4 are both connected to a driven machine 5, here indicated as being a centrifugal pump. I In conduit 2 is a regulating valve 6 actuated by a speed governor 7 through the intermediary of a fluid actuated motor 8, the arrangement including the usual pilot valve and follow-up con nections. The construction and operation of an arrangement of this type is well understood and requires no detailed description. With the arrangement shown, when the speed of the turbine decreases the speed governor lifts governor lever 9 to effect an opening movement of valve means 6, while when the speed of the turbine increases the speed governor moves governor lever 9 downward to eff ct a closing movement of valve 6. Normally the machine 5 is driven by electric motor 4, governor 7 being so set that at the normal operating speed for motor 4, valve 6 hev d closed. lvhen the speed drops below predetermined low value, due, for example, to failure of motor 4, speed governor 7 effects the opening of valve 6 to admit elastic fluid to the turbine, whereby the turbine takes up the load.

According to my invention, I provide in coi'uiection with a set of foregoing type, a valve 10 which is located in conduit 2, and which performs the function of both a quick opening valve and a quick closing valve. Normally, valve 10 is held closed by a catch, which catch is released when the speed of the set decreases below a predetermined low value to permit the valve to open, and in coni'aection therewith means are provided whereby, in case the speed of the turbine exceeds a predetermined high value, valve 10 is closed.

Referring particularly to Fig. 2, 11 indicates thostem of valve 10 and 12 indicates a casing which contains the operating mechaniisi'n for the valve. The upper end of stem 11 is connected rigidly to a piston 13, which slides in casing 12 and is held from turning a key 14. which projects into a vertical groove 15 in the wall of piston 13. Beneath p ston 13 is a spring 16, which is under comp sion and acts in a direction tending to force piston 13 upward. In the side of piston 13 is a notch with which engages a catch 17, pivotally mounted in the side of casing 12. Connected to the outer end of catch 17 is an arm 18 (see Fig. 1) which is connected by a link 19 and a bell crank lever 20 to a rod 21, the lower end of which lies in the path of movement of a finger 22 connected to the stem of speed governor 7. 23 is a spring which acts in a direction to normally hold catch 17 in engagement with the notch in piston 13. Vith the above described arrangement, when the speed of turi'iine 1 decreases below a predetermined low value, the stem of speed governor 7 moves upward sulliciently to bring linger 22 into engagement of lower end of rod 21, thereby raisin the rod and turning catch 17 to a position wherein piston 13 is released. When piston 13 is released, spring 16 moves it upward to quickly open valve 10. Valve 10 thus acts as a quick openmined low value.

Connected to and forming in substance a continuation of stem 11 is a stem extension Ql, which connect. d to the upper end of stem 11 and to piston 13 by a thrust bearing which permits stem extension 24 to be turned relatively to tem 11 and piston 13. Stem extension :Zl ireaded as is indicated at 23*, and on threads r an elongated nut Eli. pro ideal on one side with key 2. which slides in a groove 28 on the inner surface of a sleeve 2) which surrounds stein extension E-l and forms a part of a piston 30. Nut 26 adapted to travel on stem extension El between a collar 31. lixed on stem extension 2st and an inturned flange 32 on the upper end of sleeve 29. Located between a head 33 lined on the upper end of casing 12 and piston 80, is a spring ill which acts in a direction tending to force piston downward in casing 12. Piston 30 held normally ainst move inent by a catch 35, which engag in a notch in the side of piston Catch is pivoted in the side of casing 12 and at one end is connected by an arm 36 (see Fig. 1) to a link 37, which in turn is connected by a bell crank lever 38 to the upper end of a trip rod 39. The lower end oi trip rod 39 stands in a position to be engaged by the plunger 01" an emergency governor 40 arranged on the tun bine shait. ll is a spring which acts in a direction to hold catch 35 in engagement with thenotchin piston 23 Piston 30 is held from turning by a key l2, which engages in vertical slot 13-3 in its side wall. Connected to the upper end of valve stem extension 2i is a hand wheel it. by means of which stem extension Ql may he turned. Normally piston is held in the position shown in Fig. 2 by catch In case the speed oi the turbine exceeds the predetermined high value, the plunger of emergency governor in will fly out due to a centrifugal force and strilze L119 lower end of rod 39. thereby raising the rod and turning cat h 35 to rol piston 30, whereupon spring ill will force the piston downward. If t this time valve 10 opened it will be forced shut, spring l-l being stronger than sprii During normal operation, the parts occupy the positions shown in drawing, valve 10 being held closed. If the speed of the turbine decreases below a predetermined low value. catch 17 will be turned to release piston 13, as already explained, and spring 16 will force piston 1-3 upward, bringing it into engagement with the lower surface of piston 30, which forms a stop to limit its upward movement. Also the space between the two pistons functions as a dash-pot to cushion the movement of the piston. \Vhen piston 13 moves up 'ardly, it carries with it stein extension 24, and nut 26. the upper end of nut 26 coming closer to inturned tlange S2. The surrounding flange of hand wheel 4st slides on the up per end of casing 12. To close 'alve 10 again, hand wheel 4:4 is turned in a direction to cause nut 26 to travel up stem 2%, and after the nut StllliQS flange 32 continued turning of the hand wheel in the same direction will force stem extension 2i, stem 11 and piston 13 dtnvnward until the valve is again seated, catch 17 engaging its notch in the piston. Hand wheel il is then turned the other direction to run nut 26 down the stem extension to its normal position.

It, while valve 10 is open, catch 35 is moved from engagement with the notch in piston 30, whereby the piston released, the piston will be moved downward by spring 34:, forcing valve 10 to closed position. As stated above, spring Ell is stronger than spring 16. To rethe mechanism, hand wheel l4 is turned in a direction to cause nut 26 to travel upward on stem extension 24:, whereby the upper end ol the nut engages flange and forces piston 30 upward against the action of spring 34: until catch engages in the notch in piston 30. Hand wheel ll is then turned in the opposite direction to bring nut 26 back to the position shown in Fig. 2.

lVhile I have described the invention especially in connection with a three-unit set, it is to be understood that the invention is not limited thereto necessarily, but may be utilized wherever it may be found to be applicable.

llhat I claim as new and desire to secure by Letters Patent oi the United States is:

l. The combination with an elastic fluid turbine. of a valve controlling flow of elastic fluid to the turbine, means which effects the opening of said valve when the speed 01 the turbine decreases below a certain low value. and means which ellects the quick closing of said valve when the speed oil the turbine exceeds a predetermined high value.

The combination with an elastic fluid turbine having a regulating speed governor and an emergency speed governor, of a valve controlling [low of elastic fluid to the t-urbine, means actuated by the regulating speed governor to oil ct opening of said valve when the .ape .l of the turbine decreases below a certain low value, and means controlled by the emergency speed governor which effects closing of said valve when the speed exceeds a certain high value.

3. A valve structure comprising a seat. a valve adapted to engage the seat, a stem for the valve, a piston to which the stem is connected, a spring Which moves the piston in a direction to open the valve, a catch for holding the valve closed a V ainst the action of said spring, a stem extension pivotally connected to the end of said stem, a nut threaded onto said stem extension, a second piston located above the first piston, a spring which tends to force said piston in a direction to close the valve, a catch for holding said second piston against the action of such spring, a flange carried by the second piston and adapted to be engaged by said nut, whereby the second piston may be moved by said nut traveling along the stem, and means for releasing said catches.

4. A valve structure comprising a seat, a valve adapted to engage the seat, a stem for the valve, a piston to which the stem is connected, a spring which moves the piston in a direction to open the Valve, a catch for bolding the valve closed against the action of said spring, a stem extension pivotally connected to the end of said stem, a second piston located above the first piston, a spring which tends to force said second piston in a direction to close the valve, a catch for holding said second piston against the action of such spring, means for releasing said catches, and means actuated by the stem extension for resetting said pistons.

In Witness whereof, I have hereunto set my hand this 12th da of September, 1929.

JO ANNES SCHMIDT.

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