US1136910A - Governing means for engines. - Google Patents

Description

F. HODGKINSON. GOVERNING MEANS FOR ENGINES.

APPLICATION FILED AUG-27. l910 Patented Apr. 20, 1915.

- INVENTOR M AM; Ola-"Mk A;

WITNESSES V My invention relates to NTTE STATES PATEN orrion.

FnaNoIs iioneKINsoN, or EDGEWOOD PARK, PENNSYLVANIA, ASSIGNOB, BY MEsNE ASSIGNMENTS, To THE COLONIAL TRUST CCMPANY, TRUSTEE, or PITTSBURGH, PENNSYLVANIA, A CORPORATION or PENNSYLVANIA.

Specification of Letters Patent.

Patented Apr.20,1915.

Application filed August 27, 1910. Serial No. 579,243.

To all whom it may concern Be it known that I, FRANCIS HooeKINso a subject of the King of Great Britain and Ireland, and a resident of Edgewood Park, in the county of Allegheny and State of Pennsylvania, have made a new and useful Invention in Governing Means for Engines, of which the following is a specification.

governing means for turbines or other fluid pressure engines; that is to means for delivering variable amounts of fluid to an'engine for the purpose of controlling its operation.

An objectof my invention is to produce means for exerting a closing force on a' fluid delivery valve, forming a part ofsuch a governing means,.thus forcibly holding it to its seat and reducing the chance for leakage, and for automatically overcoming or removing the closing force prior tothe time of opening the valve so that it may be easily opened with a small expenditure of energy. 7

A further object is to produce a turbine or engine governing mechanism employing a normal load valve and an overload valve, and in which means are utilized for exerting a closing force on the overload valve during normal loads, and for removing or overcoming the closing force during overloads so that the valve may be operated with ease.

A further and more specific object is to produce a normal load valve and overload valve, with which pressure actuated means are employed for holdlng the overload valve firmly on its seat with considerable force during normal loads, and for automatically overcoming the closing force on the valve when the proper time for opening the valve arrives.

These and other objects I attain in a controlling mechanism embodying the features herein described, and illustrated in the drawings accompanying this application and forming a part thereof.

In the drawings, Figure 1 is a diagrammatic arrangement of governor actuated valves embodying my invention, the valves and valve casing are shown in section for convenience of illustration. Fig. 2 is a section along the broken line II-II.

The embodiment of my invention illusdivided, by suitably hereinafter trated is shown in connection with a normal load valve 4 and an overload valve 5. The arrangement of the valves is such as may be employed in controlling the delivery of motive fluid to the initial stage of a turbine and through a by-pass passage to a stage of lower pressure. It may also beemployed for delivering motive fluid to a turbine or engine, which is arranged to receive fluid from one valve during normal loads and an increased supply of fluid through two or more valves during overloads;'or, it may be employed in connection with engines or turbines in which a number of successively opening valves are employed.

The valves illustrated are inclosed within a single casing 6, which is so arranged that all of the motive fluid traversing the casing first passes the valve 4. The casing is arranged diaphragms 7 and 8, into chambers 9, 10 and 11. The chamber 9 communicates through an inlet port 12 and piping" (not shown) with a source of fluid pressure and forms in efi'ect a steam chest for the valve 4. The valve 4 is shown as a balanced puppet valve and controls the delivery of fluid from the chamber 9 to the chamber 10 through a port provided in the diaphragm 7. The chamber 10 is provided with a port 13 which may communicate with the initial stage of a turbine through suitable piping 14. This chamber is in effect a steam chest for the valve 5, which, like thevalve 4, is illustrated as a balanced puppet valve and controls the deliveryof fluid from the chamber 10 to thechamber 11 through a port formed in the diaphragm 8. The chamber 11 is provided with a port 15, which may communicate with a secondary or low pressure stage of a turbine through suitable piping 16.

For convenience of description, I will 95 consider the valves, the valve mechanism and the governing device illus trated, as forming a part of the governing mechanism of a turbine.

The valves 4 and 5 are shown in connection with a speed responsive governor 17 and a system of links and levers actuated .anism illustrated are more or less diagram matic, and it will be understood that improved and well known meansmay be employed for utilizing the varying positions of the centrifugal balls 18 of the governor in actuating the valves. The valve t is provided with a valve stem 19, which is shown pivotally connected to a bell-crank lever 20,

V which is operated through a link 21 and a is pivotally connected to 15 passing through the valve will not be throt tled-before the valve 5 is lifted from its seat. This is accomplished in the mechanism illustrated by providing an adjustable lost-motion connection 27 between the rod 26 and the bell-crank 25. The valve l is so arranged that ,the flow offiuid passingit into the chamber will not be appreciably efiected by its further movement after the its seat when the valve is closed, or during valve 5 is open. j The apparatus "thus far described is incapable of forcibly holding-the valve 5 to normal loads on the turbine; and consequently I provide a mechanism for performing thiszfunction and holding the valve forcibly to its seat'for the purpose of preventing leakage of motive fluid through it.

To this end, I provide a piston 28 on the valve rod 23 of the valve 5 and locate it within the cylinder 24L. The cylinder 24: is formed in a cover 29 of the chamber 10 and is closed at its upper end by a head 30,

through which the stem 23projects. The upper portion of the cylinder 24:, above the piston 28, communicates with the chamber 9 through piping 31; and the lower portion, below the piston, communicates with the chamber 10 through a passage 32 provided in the cover 29. IVith this arrangement, one side of the piston 28 is always sub- 1 jected to the fluid pressure in the chamber; 9 and the other side is always subjected to the pressure in the chamber 10. This operation of the apparatus is as follows: During normal loads on the turbine, the function of governlng 1s lmposed on the'valve' 4E and consequently it operates to proportion the amount of fluid delivered to the turbine through the port 13 in accordance with the load demands. This is accomplished by causing the valve 4: to occupy different posi tions corresponding to the varying speeds of the turbine and to throttle the flow of steam from the chamber 9 to the chamber 10. By throttling the flow of fluid in this manner, thepressure inthe chamber 9 is maintalned above the pressure in the charm ber 10, and consequently the fluid pressurein the cylinder 2st above the piston 28 preponderates over the fluidjpressure below the 7 piston, and operates to holdthe valve 5 firmly on its seat. As the load on the turbine increases, the valve it is movedby the operation of the governor, to openthe port between the chambers 9 and 10 greater and greater amounts and'to decrease the throttling of the fluid entering the chamber 10.

At full load onthe turbine, the valve& is fully open and it does not throttle the flow of fluid into the chamber '10, and consequently-the pressures in the c ambers 9 and 10 are approximatelyrqualg Under these valve 5 by the fluid pressureabovethepis- 'ton 28' is removed or overcome, since the pressure in the cylinder 24'below the piston 28 balances the pressure-above the piston. As the load on the turbine increases above conditions, the closing force exerted on the V the normal load, the governor operates to 7 open the valve 5 and to supply motive fluid to the turbine through the portlfi of the valve casing, as well as the portl'ip,

It will'be seen that my inventionpros vides means for holding the valve 5 lirmly onits seat'with consider-able force-through a certain range of loads on the turbine, or through a'certain range of governor travel and for automatically removing'orovercom- 1 ing the closing force at the proper time;

that is, at or just prior to the opening of the valve, or When'full pressure is obtained in; the chamber 10. i

In the apparatus illustrated, I have pro-' vided anadjusting screw or bolt'for varying the lost motion between the rod 26 and the bell-crank 25, and consequently forvnrying so adjust the apparatus that the valve 5 will start to open and to deliver motive fluid to the turbine at a time when the pressure in the chamber 10 is a few pounds less than in the chamber 9. By this arrangement, Iishift the governing function from the valvelt to thevalve as soon as the valve 5 isopened;

Having now descrlbed my invention, what i I claim is V 1 In combination with a supply valve for an engine, means for exertlng a closing force on saidvalve,-means for overcoming or removing said force prior to the opening of said valve and governor controlled means for openlng said valve.

the operation of the-valve 5. I preferably 2. In combination with a supply valve for I an engine, fluid pressure means for imposing a closing force on said valve, means for automatically overcoming said force and governor actuated means for opening said valve.

3. A control mechanism for an engine 1 comprising a valve for delivering motive fluid to the engine, an auxiliary valve for delivering an auxiliary supply of motive fluid to the engine, a governor for controlling the operation of both valves, and pressure actuated means responsive-to variations in the'pressure of the fluid delivered by the first mentioned valve for imposing a closingi'orce on the auxiliary valve while said valve is closed and for relieving said auxiliary valve of the closing force, prior to the opening of said valve in response to the operation of the governor.

4. In combination with a supply valve for an engine, fluid actuated means for imposing a closing force on said valve, governor controlled means for overcoming said force and means connected to and operated by the I governor for opening said valve.

5. In combination with the supply valve of an engine, means subjected to opposing fluid pressures for exerting a closing force on the valve, governor actuated means for equalizing said opposing fluid pressures and 'means connecteclto and actuated by the governor for opening said valve.

6. In combination with a supply valve of an engine, a piston subjected to opposing fluid pressures for exerting a closing force on said valve, governor controlled means for equalizing said pressures and means connected to and actuated by the governor for opening said valve. a

7 In combination with a supply valve of an engine, a piston subjected to opposing fluid pressures for exerting a closing force on said valve, a governor actuated valve for equalizing the pressures on said piston and means connected to and actuated by the governor for operating said valve.

8. In combination with the normal and overload valves of an engine, load responsive means directly connected to said valves and fluid actuated means for imposing a closing force on said overload valve during normal loads on the engine and for overcoming said force during full and overloads on said engine.

9. In combination with the normal and overload valves of an engine, a governor connected to said valves and having connection therewith for opening the valve and for opening the overload valve after the normal load valve is open and fluid actuated means for imposing a closing force on said overload valve and for overcoming said force during the operation of said overload valve.

10. In combination with a normal and overload valve of an engine and a governor, means connecting the governor and the valves for operating both of said valves in series and means for imposing a closing force on said overload valve while it isinnormal load operative and for overcoming said force during itsoperation.

11. In combination with a normal and overload valve of an engine, a governor, meansconnecting the governor and the valves for operating both of said valves in series and means for imposing a closing force on said overload valve while it is inoperative and for overcoming said force prior to the opening of said valve.

12. In combination with the normal and overload valves of an engine, speed responsive means for opening said normal load valve and for opening said overload valve after said normal load valve is opened and means subjected to opposing fluid pressures for exerting a closing force on said overload valve while said valve is inoperative.

13. In combination with the normal and overload valves of an engine, a governor for controlling the operation of the valves, a piston for exerting a closing force on said overload valve, means for admitting fluid pressure from the valve chest of said normal load valve to one side of said piston, and means for admitting fluid pressure from the valve chest of said overload valve to the other side of the said piston.

14. The combination of a supply valve and an overload valve on an engine, of a speed responsive means connected to the supply valve, a lost-motion connection between said speed responsive means and the overload valve, and means for imposing a closing force on the overload valve during normal loads on the engine and for overcoming said force during full and overloads on said engine.

15. A turbine control mechanism, comprising a valve for delivering motive fluid to the turbine, a second valve for delivering motive fluid to the turbine, a governor controlling the operation of both the valves to successively open and close said valves in response to variations in the load on the turbine, and pressure actuated means, responsive in operation to the operation of the first mentioned valve for imposing a closing force on the second valve prior to the opening of said second valve in response to the operation of the governor and for relieving said second valve of the closing force, while it is in operation in response to the operation of the governor.

16. A control mechanism for a turbine, comprising a valve for delivering motive fluid to the turbine, a second valve for delivering motive fluid to the turbine, speed responsive means for successively opening and closing said valves in response to varia tions in the speed of the turbine, and means subjected to the pressure of fluid delivered to and the pressure of fluid delivered by said first mentioned valve for imposing a closing force on the secondvah'e while said snbscribedmy spouse to the, operation 'of the speed respon- S1VG means.

In testimony whereof, I have hereunto Copies of this patent maybe obtained for five cents each, by addressi Washington, D. 03.

name t'his 26th day offlug ust' FhANQISHODGKINSON,

- (1 W. MOGHEE, E. W. MoGnnLls'rnn.

11g the Commissioner 6f Patents,

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