US963811A - Governing mechanism for elastic-fluid turbines. - Google Patents

Description

F. SAMUELSON.

GOVERNING MECHANISM FOR ELASTIC FLUID TURBINES.

APPLIOATIbN FILED NOV. 17. 1905.

963,81 1 Patented July. 12, 1910. g BSKEETB-SHEBT 1.

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' 2a /0 l0 l3 Witnesses. Inventor.

THE NORRIS PETERS can WASFHNGTON. n. c.

Q I Frederick STfiUGlSfiu F. SAMUELSON. GOVERNING MECHANISM FOR ELASTIO FLUID TURBINES.

APPLIOATION FILED NOV.17, 1905.

Patented July 12, 1910. 2 smmwsnnfl 2.

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- Witnesses Inventor. Frederick Samuelson;

ms NORRIS PETERS 0a., wnsnmcton, n c.

UNITED ETATES PATENT OFFICE.

FREDERICK SAMUELS ON, OF RUGBY, ENGLAND, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

GOVERNING MECHANISM FOR ELASTIC-FLUID TURBINES.

To all whom it may concern.

Be it known that I, FREDERICK SAMUEL- son, a subject of the King of Sweden, residing at Rugby, England, have invented certain new and useful Improvements in Groveining Mechanism for Elastic-Fluid Turbines, of which the following is a specification.

The object of my invention is to provide improved governing mechanism for steam turbines which shall be simple in construction and reliable in operation.

My invention comprises essentially a mechanism in which a piston working in a cylinder is employed to control the amount of steam admitted to the turbine, this piston being subjected on one side to the pressure in the steam supply conduit of the turbine and on its opposite side to the pressure of a fluid or liquid which is admitted to and exhausted from the cylinder under the con trol of a speed governing device so as to vary the pressure of fluid or liquid opposing the steam pressure, thereby causing movement of the piston in such a manner as to control a valve or valves or a device governing the movement of a valve or valves so as to vary the amount of steam admitted to the turbine in accordance with the/load conditions.

My invention further comprises the details of construction and arrangement of apparatus hereinafter described.

In order that the invention may be readily understood 1 will now describe its application to a turbine of the type in which the steam is admitted through a number of closely associated nozzles arranged in groups around the turbine Wheel.

The accompanying drawings illustrate the invention as designed particularly for use on a turbine having two groups of admission nozzles, but it is to be understood that it is equally applicable with obvious modifications to a turbine in which a single group or more than two groups of admission nozzles is employed.

In the drawings, Figure 1 represents a front elevation, partly in section, of part of a vertical shaft turbine fitted with my improved governing mechanism; Fig. 2 is a plan view of the turbine shown in Fig. 1, also partlyin section; Fig. 3 is a side elevation of the same; Figs. 4 and 5 are detail sectional views on a larger scale; and Fig.

Specification of Letters Patent.

Application filerl November 1'7, 1905.

Patented July 12, 1910.

Serial No. 287,822.

6 is a side elevation of a vertical shaft turbogenerator on a small scale.

I11 the embodiment of my invention illustrated in the accompanying drawings, 1 represents the casing of an elastic fluid turbine of the Curtis type. Mounted on this casing is a pedestal 2 which may support a generator casing 3. The movable element 4 of the turbine is illustrated in section in Fig. 1 in which figure is also shown one of the elastic fluid admission nozzles 5 of which there are two groups arranged one at each side of the turbine casing. These groups are provided with controlling devices A and B respectively. Controlling device A will be first described.

Above each group of nozzles is provided a valve chest 6 which communicates directly with the steam supply conduit 7 and through ports 8 with the nozzles. The valve chest is fitted with a slide valve 9 which is adapted to move to and fro over the ports and control the supply of steam to all the nozzles in the group. The valve chest 6 is closed at one end and opens at its other end into a cylinder 10 within which is fitted a pair of pistons 11 and 12 arranged at a suitable distance apart upon an actuating rod 18, which rod is also connected to the slide valve 9. Piston 11 forms the steam piston and has one side exposed to the steam pressure within the valve chest. The other piston 12 forms the liquid pressure piston and is separated from the steam piston by an air-space 14 so as to prevent the liquid from causing condensation of the steam.

The actuating rod 13 which carries the two pistons and the slide valve extends through a stufling box 15 at the end of the liquid pressure chamber 10. A similar controlling device B for the second group of nozzles is arranged at the opposite side of the turbine wheel 4: illustrated on the right hand side of Figs. 1 and 2. The efiective piston area of the motor of this controlling device is preferably considerably smaller than that of the cylinder of the controlling device A. The slide valve and arrangement of steam and liquid pistons in this device are the same as in the device which I have just described, but the cylinder 10 of this device is connected through a pilot valve 16 to any convenient source of liquid supply under pressure and to the cylinder of the first mentioned device A, through the pipe 17 so that the governin mechanism A can only receive its supply 0? liquid or be exhausted through the cylinder of the governing device B. The passage of liquid between the two cylinders is controlled by an automatic valve 18 (clearly illustrated in Fig. 4:), actuated by the movement of the slide valve controlling the right hand or second group of nozzles B.

The area of the liquid pressure piston of the controlling device B for the second group of nozzles is smaller than the area of the piston of the controlling devices of the first group so that no movement thereof takes place until the first nozzle-controlling pistons 11 and 12 are moved to the full extent of their travel.

In order to control the flow of liquid to and from the liquid pressure cylinders of the two devices, a pilot valve 16, clearly illustrated in Fig. 5, is provided which is operated by the centrifugal governor driven by the turbine shaft. This valve controls three passages 19, 20 and 21 one of which 19 is open to the supply of pressure liquid, another of which 20 forms an exhaust passage, and the third 21, connects with the cylinder of the valve governing mechanism B. The passage 21 may be put in communication with either the supply or exhaust connections 19 and 20 by movement of the pilot valve. Any suitable source of liquid or fluid pressure supply may be used, but I prefer to employ the liquid (which may be water or oil) that is used to lubricate the one or more bearings of the turbine, so that if the pressure of lubricating fiuid to one or more of the bearings fails the turbine motive fluid pressure will move the controlling valves automatically to their closed position, shutting off the supply of fluid to the turbine.

The ports 8, Fig. 2, leading to the nozzle openings and controlled by the slide valves 9 may be arranged in any suitable manner, but I prefer to employ an arrangement such as shown on the left hand of Figs. 1 and 2 in which half of the ports 8 are located at one side of the center of the valve chest 6 and the other half at the opposite side of the center in alternating or offset relation to the first half, each opening being of triangular form, as it enables a closer packing of the openings and better regulation to be obtained.

It will also be observed that half of the passages leading from the ports extend from the right-hand side of the center of the valve chest to the nozzles 5, while the other half are offset with respect to the first and extend from the left-hand side of the center to said nozzles. These discharge passages leading from the ports terminate in the same plane, namely, that of the receiving portions of the groups of nozzles 5, and are arranged in alternate order.

The automatic valve shown in Fig. 4: which controls the sup ly of liquid between the liquid cylinders or the two valve controlling devices, is arranged on the actuating rod 13 of the pistons of the controlling device B for the right hand or second group of nozzles. This valve comprises a sliding collar 22 upon which is arranged a hydraulic packing 23 adapted to engage with a ring seat 24: surrounding the piston rod 13. This collar is acted upon by a spring 25 seated on a fixed shoulder and is normally held out of contact with the ring seat 2& by an outwardly curved projection 26 on the piston rod when the latter is in the position corresponding to the closed position of the slide valve. This is the relation in F ig. 4:. In this case there is a free communication for liquid from the pilot valve through pipe 21, passage 27 and pipe 1'? to the cylinder of the controlling device A.

Then the apparatus is in operation the liquid is admitted as just described to. the liquid cylinder of the controlling device A causing its slide valve to open the nozzle passages and admit steam or other elastic fluid to the turbine wheel. This movement continues until the valve is fully open when the pressure within the two liquid cylinders is raised sufliciently to initiate the movement of the piston of the second controlling device B. As soon as this takes place the projection 26 on the actuating rod 13 of the piston moves to the right through the ring seat 24 of the automatic valve, relieving the pressure on the spring controlling the collar 22 which forms the movable portion of the valve. The collar 22 is then forced by the spring 25 into contact with the ring seat 24: preventing the exhausting of liquid from the liquid cylinder of the controlling device A which has just operated. The movement of the piston and valve of the controlling device B then continues, admitting steam to the nozzles of the second group until the pressure is arrested by the governor operated pilot valve 16. It will thus be seen that the pistons of the two devices are interlocked and that the movements must take place in a definite sequence.

When the speed of the turbine varies in such a manner as to necessitate the shutting off of the steam, the reverse of the operations above described takes place, the pilot valve then establishing communication between the cylinders and the exhaust relieving the pressure on the liquid pistons and allowing the pressure in the valve chests to operate on the steam pistons to close the valves. It will also be understood that during normal operation, if the load on the turbine diminishes, the liquid pressure is reduced and the steam piston moves so as to cause the slide valve to reduce the steam opening by the proper amount.

The mechanism by means of which the pilot valve 16 is operated by the governor consists of a lever 28 which has one end attached to an adjustable link 29 controlled by the shaft governor and also to an adjustable spring 31 by means of which the speed of the turbine may be regulated. The lever 28 at or near its central portion is pivotally connected with the actuating rod 32 of the pilot valve 16 and the outer extremity of the lever is connected through a bell-crank lever 33 to a link 34 which couples together the valve actuating rods of the two nozzle controlling devices A and B. When the governor operates, it causes the lever 28 to be raised or lowered against the force of the controlling spring and at the same time raises or lowers the pilot valve so as to supply or exhaust liquid from the cylinders of the controlling devices. The lever 28 in this case pivots round the extremity supported by the bell-crank lever 33 which connects said lever to the link 34 connecting the valve actuating rods of the two controlling devices. lVhen the governor operates to establish a given load condition, the movement of the actuating rods which is then caused, actuates the bell-crank lever connections in such a way as to raise or lower the pilot valve controlling lever from its opposite end, the lever then pivoting about its end connection with the governing mechanism, and the pilot valve being moved into such a position controlling the liquid supply as to maintain this load condition. To state the 'matter in another way the shaft governor opens the pilot valve and a piston starts in motion, and this motion, through the bell crank lever, restores the pilot valve to its initial position, the parts involved in this movement constituting a follow-up or restoring device to prevent overtravel of the pistons.

It will be obvious that where only a single liquid controlling device is used, a similar governor controlling mechanism is applicable, the governor serving to cause the pilot valve to move in such a way as to establish a given load position of the slide valve and the movement of this slide valve toward this position being used to return the pilot valve to a position in which it brings the slide valve to rest in its regulated position.

Where more than two groups of inlet nozzles are employed interlocking devices such as above described and illustrated in Fig. 4

will be fitted to each of the cylinders except the one controlling the valve first operated, the effective piston area of each of the cylinders diminishing from the first operated to the last, in order to insure their operating in proper order as described above.

It will also be obvious that instead of the pistons actuating a slide valve to cover and uncover the steam ports they may actuate valve operating mechanisms such as for example a cam rod adapted to raise and lower the inlet valves as shown in British patent No. 2727 5 of 1903 corresponding to United States patent to Oscar Junggren, 796,482, dated Aug. 8, 1905.

In Fig. 6 is shown on a small scale a turbogenerator of the vertical shaft type. 40 represents the shaft governor that responds to speed variations and is connected to the pilot valve 16 through suitable connectors. 41 represents the step-bearing that supports the main shaft, the latter being common to the turbine and generator. Fluid under pressure, such as water or oil, is admitted to the hearing by the conduit 42. Connected to the conduit is the pipe 19 leading to the pilot valve so that when the pressure supply fails the controlling devices will shut off the supply of steam or other elastic fluid to the turbine.

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 represent the best embodiment thereof; but I desire to have it understood that the ap paratus shown is only illustrative, and that the invention can be carried out by other means.

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

1. An elastic fluid turbine mechanism for controlling the admission of motive fluid to the turbine wheel comprising a cylinder, means supplying lubricant under pressure to the turbine, a piston operating in said cylinder and acted upon on one side by the pressure of the motive fluid supplied to the turbine and on the other side by fluid under pressure from said means, a pilot valve operated by the turbine governor for controlling the admission of fluid from said means to the cylinder and its exhaust therefrom, and a follow-up device for the pilot valve.

2. An elastic fluid turbine mechanism for controlling the admission of steam to the turbine wheel comprising a cylinder, means supplying lubricant under pressure to the turbine, a double ended piston operating in said cylinder, one end of said piston being acted upon by the steam supply of the turbine and the other by liquid under pressure from said means, a valve operating mechanism located in the steam chest and connected to said piston so as to uncover and cover ports leading to the inlet nozzles as the piston reciprocates, a pilot valve controlling the admission of said liquid to the cylinder, and a speed responsive device adapted to operate said pilot valve.

3. In combination, an elastic fluid turbine having a plurality of groups of nozzles, mechanism which opens and closes the nozzles of each group in successive order to control the admission of fluid to the turbine wheel, motors for actuating said mech anism, a speed responsive device for controlling the supply of energy to the motors, and means for preventing the'admission of fluid by said motor-actuated mechanism to any of the nozzles of one group until all of the nozzles of the preceding group have been opened.

4. In combination, an elastic fluid turbine, having a plurality of groups of inlet nozzles, with mechanism including pressureactuated motors for controlling the admis sion of fluid to the turbine wheel, and an interlocking device between the motors for preventing the closing of the nozzles of one group until all of the nozzles of the following group have been closed.

5. An elastic fluid turbine mechanism for controlling the admission of fluid to the turbine wheel comprising a fluid pressure operated piston, a cylinder therefor, and a valve operated by said piston adapted to open and close the fluid admission ports, the supply of fluid pressure to the piston cylinder being so arranged that the valve automatically closes the admission ports when the supply of lubricating fluid to the turbine bearing fails, substantiallv as described.

6. An elastic fluid turbine mechanism for cont-rolling the admission of fluid to the turbine wheel comprising a valve controlled by the movements of a reciprocating motor having a piston adapted to open and close the ports admitting fluid to the turbine wheel, said piston working in a cylinder and being acted upon on one side by the pressure of the fluid supplied to the turbine and on the other side by the pressure of the liquid supplied to lubricate the turbine shaft bearing, in such a manner that when the supply of lubricating liquid to the turbine bearing fails, the turbine fluid applied to the turbine automatically operates the piston and valve so as to close the admission ports, substantially as described.

7. In a governing mechanism for elastic fluid turbines, the combination of a chest through which motive fluid passes to the turbine, ports therein arranged in a group and admitting fluid to a turbine wheel, a device located in the chest for covering and uncovering the ports as the demand for energy changes, means for supplyin lubricating fluid under pressure to the turbine, a motor for actuating said device that is subjected to the motive fluid admitted to the chest for moving it in one direction and to liquid under pressure from said means for moving it in the opposite direction, and a pilot valve responding to load changes for admitting liquid from said means to and cutting it off from said motor.

8. In a governing mechanism for elastic fluid turbines, the combination of inlet ports arranged in groups, a device for each group arranged to cover and uncover the ports as the demand for energy changes, motors for actuating the devices that are subjected to the fluid admitted to the turbine for moving them in one direction and to a separate source of fluid under pressure for moving them in the opposite direction, and a pilot valve that is common to and controls the motors.

9. In a governing mechanism for elastic fluid turbines, the combination of inlet ports arranged in groups, devices for covering and uncovering the ports as the demand for energy changes, motors for actuating the devices that are subjected to the fluid admitted to the turbine for moving them in one direction and to a separate source of fluid under pressure for moving them in-the opposite direction, a mechanical connection between the moving elements of the motors, a pilot valve for controlling the motors that moves in response to load changes, and a follow-up device for the pilot valve that is actuated by the connection.

10. In a governing mechanism for turbines, the combination of a plurality of fluid-regulating devices, motors for actuating them which are moved by liquid under pressure, the moving elements of the several motors having difl'erent eflective areas which are acted upon by the liquid, and a means causing the liquid to operate the motors one after the other.

11. In a governing mechanism for turbines, the combination of fluid-regulating devices, motors for actuating them which are moved by liquid under pressure, the moving elements of the motors having diflerent effective areas which are acted upon by the liquid, and a valve responding to the movement of one motor for controlling the action of another.

12. In a governing mechanism for turbines, the combination of fluid-regulating devices, motors for actuating them, comprising pistons and cylinders which are actuated by liquid under pressure, conduits for conveying liquid through one motor to another, and a valve which remains in a given position until one motor has moved to its limit and then moves to a position which admits fluid to another motor.

13. In a governing mechanism for turbines, the combination of fluid-regulating devices, motors for actuating them, comprising pistons and cylinders which are actuated by liquid under pressure, conduits for conveying liquid through one motor to another, and a valve mounted on a moving part of one of the motors which is closed by fluid pressure and positively opened by the movement of the motor.

14. In a governing mechanism for turbines, the combination of regulating devices,

motors for operating them comprising relatively movable parts, a pilot valve controlling the motors, a connector that is secured to the moving partof each motor and restores the pilot valve to its initial position after each of its movements, and a device for moving the pilot valve in response to load changes.

15. In a governing mechanism for turbines, the combination of a plurality of triangular ports arranged in oppositely disposed IO'WS, nozzle orifices connected therewith, a slide valve arranged to move longitudinally of said roWs to cover and uncover the ports, a piston for moving the valve that is subjected to steam on one side and liquid on the other, and a speed responsive means for controlling the movements of the piston.

16. In a governing mechanism for turbines, the combination of a governor, a controlling valve, a casing in which the valve operates to control the passage of motive fluid to the turbine, longitudinal roWs of ports in the casing Which are arranged on opposite sides of the longitudinal center line of the valve and extend therefrom to the points of discharge to said turbine, and a governor controlled means Which actuates the valve and causes it to move over said ports.

17. In a governing mechanism for turbines, the combination of a valve chest, a controlling valve mounted therein, ports and passages arranged at opposite sides of the valve, the passages terminating in the same plane and alternating one With the other, a motor for operating the valve, and a governor controlled means regulating the act-ion of the motor.

18. In a governing mechanism for turbines, the combination of a valve chest, a controlling valve mounted therein, ports arranged at opposite sides of the valve, those on one side being offset With respect to those on the opposite side, a nozzle comprising a plurality of discharge orifices, passages connecting the ports \Vltll said orifices Which lead from opposite sides of the controlling valve and terminate in a common plane beloW it, the passages alternating one with respect to the other, a motor for operating the valve, and a governor controlled means for regulating the operation of the motor.

In Witness whereof, I have hereunto set my hand this sixth day of November, 1905.

FREDERICK SAMUELSON.

Witnesses:

ERNEST HARPER, SIDNEY GEO. WEBB.

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