US1029786A - Valve-gear for steam-turbines. - Google Patents

Description

O. BANNER. VALVE GEAR FOB. STEAM TURBINES.

APPLICATION FILED mam, 1911.

1,029,786. Patented June 18, 1912.

3 SHEETS-SHEET 1.

O. BANNER.

VALVE GEAR FOR STEAM TURBINBS.

APPLICATION FILED rEB.27,1911.

1,029,786. Patented June 18,1912.

3 SHEETS-SHEET 2.

0. BANNER.

VALVE GEAR FOR swam TURBINES.

APPLICATION FILED TE'B.Z7,1911, 1,029,786. Patented June 18,1912.

3 BHEETSSHEET 3.

Z WIZ,W&SJ&JJ wvcwtor' OTTO BANNER, OF STERKRADE, GERMANY.

VALVE-GEAR FOR STEAM-TURBINES Specification of Letters Patent.

Patented June 18, 1912.

Application filed February 27, 1911. Serial No. 611,187.

To all whom it may concern Be it known that I, O'rro BANNER, chief engineer, subject of the Kingdom of Prussia, residing at Sterkrade, Rheinland, Germany, have invented new and useful Improvements in Valve-Gear for Steam-Turbines, of which the following is a specification.

This invention relates to an-improvement in oihrelays for governing the steam inlet valves of steam turbines, and pertains particularly to a mechanism whereby the pressure required to operate the valves is gradually applied, by the interposition of an auxiliary relay.

By the present method of regulating the speed of an engine, the advantage is obtained that the changes of the load both with live and exhaust steam, instantly operate the steam valves, and the work is performed independently of the steam pressure, and with little pressure in the relay system at any time. Furthermore, the pressure is first applied, in reduced quantity, to an auxiliary device or relay, and then, in full force to the main relay, so that there is no strain on the system, which is liable to place its parts out of gear. Also, the action is such that the oil is in continual circulation, so that there is no danger of clogging the system, or of having no pressure at the instant when the valves should operate to admit more steam to the engine.

In the accompanying drawings. Figure 1 is a view, partly in elevation and partly in section, of a turbine, showing my invention applied thereto, there being a group of five relays for governing five steam inlet valves of the turbine. Fig. 2 is a sectional elevation of the main relay or control valve and the auxiliary relay or control valve. Fig. 3 is a diagrammatic showing of the relay system as it is applied to the steam chest of a turbine, two relays being connected to the system.

Referring more particularly to said drawings, a is the slidable sleeve carried by the centrifugal governor b, the latter being carried by the turbine. In the cylinder 0 a slide valve or piston d is operative and is connected to the sleeve a by means of a rod 0. The forward edge of the slide valve or piston d is adapted to cut off the channel or annular groove 9 more or less from communication with the interior of the cylinder 6,

according to the speed of the engine, for the purpose of automatically creating a pressure in the system, as hereinafter described.

InFig. 3, in which the system is diagram matically shown, 2, i1 is a spur wheel pump for lifting the oil out of the oil tank or reservoir I through the suction pipe 2 Said oil is forced under high pressure int-o the pipes Z and n, from which it is taken by branch pipes for various purposes. For instance, the branch pipe 11 conducts oil from the pressure conduit 1, n to one of the engine bearings for the purpose of lubrication.

The branch pipe v carries oil from conduit Z, a under pressure through the cylinders m of the oil relays. Tn each cylinder m ,a piston u is operative. and is connected through a rod 1 to a steam valve 0c. in the steamehcst q, (Fig. 3). A spring 3 bears against each piston u and holds it in normal position. The vavles 00 operate in the steam chamber q, as above stated, and steam is allowed to enter said chamber through the inlet The issuance of steam from said chamber or chest 1] is governed by the operation of the relay system. and its consequent effect on the valves .20. Encircling each pis- 'ton u is an annular recess p, which communicates. through the intermediacy of a passage 0 witlrthc hollow interior of the piston. ln said interior of the piston u is an auxiliary slide valve 2, which governs the passage of fluid through the passage 0 and a longitudinal canal 72, which affords communication between the interior of the piston u and the forward end of the cylinder. The slide valve 3 is connected to a stem or rod t, at the opposite end of which is a piston 1" which operates in an auxiliary cylinder m at the rear of the cylinder m and preferably attached thereto. said cylinder m constituting, with said piston .therein, an auxiliary relay. Spring 8 bearing between the piston r and the end of the cylinder m maintains the piston in its normal forward position, and holds the slide valve 2 in position to cut off communication between the passage 0 and the canal 79. A valve ;2 is located in the branch pipe 2', for placing the system in operative communication with the engine. The cylinders m are provided With return pipes w and the cylinder 0 is provided with the return pipe is, said return pipes k and w serving to return the oil to the tank or reservoir Z, after it has passed through the relays.

The operation of the system is best followed in Fig. 3, in which the controlling apparatus is diagrammatically shown. Here, two relays are shown connected in series and controlling adjacent valves w. Under ordinary conditions of running of the engine when no load is carried thereby, the piston d stands, as shown, with its front edge f more or less freezing the annular passage 9. Thus, under normal conditions, the oil will pass through the system, when pumped from the tank 1, from relay to relay through conduits *0, and after filling the relays as far as permited, that is, until stopped by the slide valves 2-, as above described. The oil will also flow through branch pipe 2', the valve y having been opened, from auxiliary cylinder to auxiliary cylinder, from thence to cylinder 6, through passage 9, and pipe k, back to the reservoir 1. When, however, the load on the engine is increased to the extent of influencing the governor Z) to draw the sleevea backwardly, the piston d will be drawn outwardly, and cover the passage 9 entirely, thereby increasing the pressure in the pipe 2' and consequently in the auxiliary cylinders m Simultaneously with this increase or pressure in, the pressure will increase in the" pipe '0. As a result, the pistons 1' will move backwardly against the action of the springs s, and thereby/slide valves 2 will be removed to place passages o in communication with canals p, when the oil under pressure in pipes 1) will fill the chambers 0 in front ot the pistons u. Under the pressure there set up, the pistons u will move rearwardly against the action of the springs 8 When thepistons u move rearwardly, the valves w are operated, and the steam in chamber or chest 9 distributed accordingly. When the machine again speeds up, so that the gov ernor b replaces valve or piston d, the pressure in the system is relieved by the consequentrestablishment of the complete circuit through the pipesi, cylinder 2 and the pipe is, and the springs s and s will return the slide valves 2 and pistons u to their normal positions. Before the slide valves 2 again shut off communication between the the passages 0 and'the canals p, the oil in front of the pistons u-will flow through canal p and the central passages in the pistons u into the chamber 0 in the rear of the pistons u, and will thence flow back into the reservoir Z through the return pipes 10. In practice, the springs s and 3 in the different relays are formed of varying strengths, so that the fluid pressure will actuate the pistons in turn, and thus give a gradual and regulated steam feed to the engine. It may, however, be desirable in certain cases to cause all the valves to be actuated at once.

While in the diagrammatic showing of Fig. 3, only two relays are shown with two steam valves, it is obvious that any number of relays may be connected in series or otherwise, with a corresponding number of steam valves, according to the needs of the engine. The relation of such a group to the engine is shownin Fig. 1, where five relays govern the five valves of the en ine. It is also obvious that, the regulation 0 the strength of the springs s and s in the different relays give a wide range of adjustability to the system in which a group of fiy e or more relays is used, so that the responses to the changes of speed will be quick and smooth. Also, the relays may be grouped to be controlled to admit either high or low pressure or exhaust steam, the pressure necessary to make the devices respond to requirements being easily regulated as above described to accommodate any steam pressure, independently of the latter, since the action of the controlling mechanism does not depend on the steam pressures.

What I claim and desire to secure by Letters Patent of the United States is 1. Valve gear for steam turbines, comprising in combination, a main piston, means to supply a liquid of constant pressure to said main piston, an auxiliary iston, a

.speed governor, and means toa just the passage of a liquid to said auxiliary piston and adapted to be controlled by said governor, substantially as, and for the purpose, set forth.

2. Valve gear for steam turbines, comprising in combination, a main piston, an auxiliary piston, a speed governor to regulate the admission of a liquid to said auxiliary piston, substantially as, and for the purpose, set forth.

3. Valve gear for steam turbines, comprising in combination, a plurality of principal pistons, a plurality of auxiliary pistons, a governor, and means controlled by said governor to regulate the admission of a liquid to said pistons, substantially as, and for the purpose, set forth.

4. A valve gear for turbines, comprising in combination, a steam valve, means for actuating said steam valve, said actuating means being controlled by fluid pressure, a circuit including said actuating means in which said fluid pressure is constantly maintained, and means governed by the speed of the engine for interrupting said constant pressure, whereby said actuating means is caused to ope said steam valve.

5. A valve gear for turbines, comprising in combination, a steam valve, means for actuating said steam valve, a circuit including said actuating means in which a constant fluid pressure is maintained, a governor controlled device also in said circuit for circuit may be communicated to said second interrupting said constant fluid pressure to piston, and means actuated by said first actuate said valve actuating mechanism, the mentioned piston, whereby, when said cirresult of said interruption being such that quit is interrupted, said fluid pressure will the constant fluid pressure is directed wholly actuate said second piston to move sai to actuating said "alve actuating mechavalve. 20 msm. In testimony whereof I have signed my 6. A valve gear for turbines, comprising name to this specification in the presence 0 in combination, a continuous circuit in which two subscribing witnesses.

a constant oil pressure is maintained, a pis- OTTO BANNER [L ton in said continuous circuit, means for ina terrupting said circuit, a steam valve, a sec- Witnesses:

ond piston adapted to actuate said steam ALFRED HENKEL,

valve, a branch whereby pressure from said A. PosiiR.

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