US1861092A - Valve operating mechanism - Google Patents

Description

Filed Nov.28,' 1930 2 Sheets-Sheet Mmmm Re M R O D mw ww NH a IIC E Y n B mzmv, E s s- E N n w@ ATTORNEY A, F. SCHWENDNER VALVE OPERATING MECHANISM May 31, 1932,

Filed N0v.28, 1950 2 Sheets-Sheet 2 INVENTOR RF. SCHWENDNER.

`Patented May 31,1932

i UNITED STATES PATENT; orifice;

" f ANTHONY F. SOHWENDNEB OF ESSINGTON, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIG MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- f 'VANIA VALVE OPERATING MEcHANIsM Application led November 28, 1930. Serial No. 498,796.

My invention relates to a valvesoperating mechanism for a plurality of valves, and it has for its object to provide an improved and simplified construction thereof.

In accordance with my invention, I provide a fluid pressure relay, enclosed in a separate housing for each valve. A cam shaft extends throughthe-housings and carries a cam in each housing for controlling the relay therein. The cam shaft is op erated by a fluid pressure relay, preferably through a crank arm fixed on the shaft.

The presentvalve operating mechanism is particularly adapted for actuatingthe adf mission valves of a prime mover under control of a governor responsive to the speed of the priine mover. i

' The above and yother objects areelected by my invention, as will be apparent from f' the following description and claims taken in connection with the accompanying` drawings forming a part of thisapplication in which:

Fig. 1 is a diagrammatic view showing the l valve operating mechanism applied to the steam chest of an elastic fluid turbine;

Fig. 2 is` an end elevational view of the valve operatingmechanism, showing the governor for operating the same in section;

Figs. 3- to 7 are detail views showing the cams for the several valves, the position of the cam shaft being thesame in all of these views; and,

Fig. 8 isa sectional view of one ofthe 'J valves and the relay for operating the same.

Referring now to the drawings more in detail, I show a steam chest 10 associated with an elastic iuid turbine 11. The steam chest includes a primary valve 13, a secondary valve 14, a tertiary valve 15, a quarternary valve 16, and a quinary valve 17. Each of the valves communicates with its corresponding section of thefturbine through a conduit 18. Y

Each of the valves is provided with a fluid pressure relay 19, includingy a separatehousing 20, shown in` detail in Fig. 8. A cam shaft 21 extends through the interior of each of the relay housings, and has a cam lixed thereon within each of said housings forv operating the relay therein. llhe cam shaft is rotatably or angularly actuated by a governor'r22, which is preferably a fluid pressure governor responsive to the speed of the turbine 11 and which embodies a fluid pressure'relay. Anv impeller 23 is mounted on the turbine rotor shaft 24 and delivers to the governor 22, through a yconduit 25; iiuid pressure varyingV as they square of the speed of the turbine.

The governor 22 is shown in detail in Fig. 2 and includes an ope-rating piston26r disposed in a cylinder 27. It is connected through ai lever 28 and a link29` to a crank arm 31 fixed on the cam shaft 21.

The piston 26 is formed with an upper tubular extension 32 which extends through vided with a chamber 34 with which the conf duit 25 communicates. The piston 26 is thus biased upwardly at all times by the fluid pressure in the chamber 34 acting on the lower end of the extension 33. It is further biased upwardly by a spring 35.

Fluid pressure is admitted to and discharged from the upper end of the cylinder 27 through ports 3G and an annular recess 3T, the latter opening into the hollow interior of the piston. An annular row of ports 38 formed in the extension 33 provides communication between the hollow interior of the piston and the lower end of the cylinder 27. The latter communicates with a discharge conduit 39.

A, pilot valve 41, in the form ofV a sleeve closed at its upper end, is disposed 'within recessL 37. Ity is further provided with an elongated recess 45 normally disposed below the recess 37.

The operation of the governor 22 is as follows:

Upon decrease in fluid pressure, the pilot valve 41 is moved downwardly by the spring 42. The ports 44 move into registry with the recess 37 and fluid pressure from the chamber 34 isadmitted through the ports 44, the recess 37 and the ports 36 to the upper end of the cylinder 27. The piston 26 is moved downwardly by said fluid pressure until communication between the ports 44 and the recess 37 is cut off. n moving downwardly, the piston 26 moves the cam shaft 21 in counterclockwise direction, through the lever 28, the link 29 and the crank arm 31.

. Upon increase in fluid pressure in the chamber 34, the pilot valve 41 moves upwardly, increasing the tension of the spring 42. The recess 45, upon the upward movement of the pilot valve, places the recess 37 in communication with the ports 38, so that fluid may flow from the upper end of the cylinder to the lower end. The piston 26 is then moved upwardly by the spring and the fluid pressure acting on the lower end of the extension 33 until communication betweeen the recess 45 and the recess 37 is cut off,

' when the Huid in the upper end of the cylinder 27 is locked in and opposes further upward movement of the piston 26. During the upward movement of the piston 26, it moves the cam shaft 21 in clockwise direction.

Referring now to Fig. 8, there is shown a section through the secondary valve and its relay 19. The other valves and the relays for operatingr the same are of similar construction. The relay includes an operating piston 46, disposed in a cylinder 47, for actuating the admission valve. The admission of fluid pressure to the cylinder 47 for operating the piston 46 is controlled by a pilot valve 48 disposed in a bushing 49.

The bushing 49 is provided with ports 51 which communicate with the upper end of the 'cylinder 47 through a passage 52, and

with a row oit ports 53 communicating with the lower end of the cylinder 47 through a passage 54. The bushing is further provided with a row of ports 55 disposed above the ports 51 and with a row of ports 56 disposed below the ports 53, the ports 55 and 56 communicating with a source of fluid pressure through a conduit 57. A row of ports 58 is formed in the bushing between the ports 51 and 53 and communicate with a discharge conduit 59. The pilot valve 48 is formed with piston portions 50 and 60, which cover the ports 51 and 53 in the cut-off position of the pilot valve.

- A lever 61 is connected at one end to the piston 46, through pivotal connection with a. rod 62 fixed to the piston 46. The other end of the lever 61 is connected to the pilot valve 48 by means of a link 63 pivoted to the lever and to the pilot valve. A lever 64 is pivoted at an intermediate point to a stationary bracket 65, which serves as a fulcrum for the lever. yThe left-hand end of the lever 64 is connected to the lever 61 at a point intermediate its connections with the piston and the pilot valve by means of a link 66 pivoted to said levers. The links 63 and 66 serve to permit horizontal movement of the connected parts of the levers 61 and 64 caused by angular movement thereof.

A cam member 67 is fixed on the shaft 21 within the housing 20. The right-hand end of the lever 64 carries a roller 68 engaging the cam surface of the cam member 67, being urged against the cam b a spring 40 acting on the pilot valve 48. he cam member 67 includes an inner circular surface 69, a second circular surface 70, and an inclined surface 71 for moving the roller 68 vertically.

The operation of the relay 19 is as follows:

Upon clockwise rotation of the cam member 67 the roller 68 is moved upwardly upon engaging the inclined surface 71. The lever 64 is tilted in counterclockwise direction, moving the link 66 downwardly. The latter moves the lever 61 downwardly about its pivotal connection with the rod 62, thereby moving the pilot valve 48 downwardly.

The downward movement of the pilot valve 48 places the port- s 55 and 51 in communication, admitting fluid under pressure to the upper end of the cylinder 47, in which it acts on the upper side of the piston 46 to move the same in valve-closing direction. At the same time, the ports 53 and 58 are brought into communication, permitting the fluid in the lower end of the cylinder 47 to be discharged through the discharge conduit 59. As the piston 46 moves downwardly, it moves the right-hand end of the lever 61 downwardly about the pivotal connection with the link 66 and raises the pilot valve 48, returning the same to cut-off position.

Upon movement of the cam member in counterclockwise direction, when the inclined surface 71 comes into Contact with the roller 68, the latter moves downwardly under force of the spring 40. The left-hand end of the lever 64 moves upwardly, permitting the lefthand end of the lever 61 and the pilot valve 48 likewise to move upwardly. The ports 53 are now placed in communication with the ports 56, admitting fluid under pressure to the lower end of the cylinder 47 to raise the piston 46. The fluid above the piston 46 is discharged through the ports 51 and 58 to the discharge conduit 59. The piston 46 thereupon moves upwardly to increase the opening of the admission valve 14, at the same time moving the pilot valve 48 downwardly to return it to cut-off position through the lever 61.

The cylindrical surface 69 of the cam member maintains the roller 68 in a position providing full opening of the admissionvalve, and the circular surface 70 maintains the roller 68 in a position providing complete closing of the admission valve. rl`he opening and closing movement of the valve is effected during engagement of the roller With the inclined surface 71, Which covers a small angle in the movement of the cam shaft 21. The time of opening and closing of each valve With respect to operation of the governor 22 is determined by the angular position of the inclined surface 71.

The cam members for the valves 13 to 17 are shown in Figs. 3 to 8, respectively. These figures show the same position of the cam shaft 21, and it Will be noted that the cam member 72 for the primary valve provides full opening thereof, While the cam member 67 of the secondary valve provides complete closing; but upon further counterclockWise movement, it Will begin movement of the secondary valve in opening direction. The cam member 73 for the tertiary valve Will re uire further counterclockwise movement be 'ore it begins to open the valve, this movement being equal to the angular movement of the shaft necessary to bring the secondary valve tov full open position. The inclined surfaces of the cam members 74 and 7 5 for the quaternary and quinary valves are successively further spaced from the rollers 68, so that said valves will open successively after the tertiary valve has opened.

It will be noted that the cam member actuates the pilot valve in the direction for effecting closing movement of the admission valve. Should the pilot valve tend to stick When the governor is operating in valveclosing direction, the cam member Will provide a positive force for moving the pilot valve, thereby guarding against overspeeding because of failure of the relay to close the admission valve.

The operation of the mechanism as a Whole Will noW be apparent and is asfollows:

Upon increase in load on the turbine and decrease in speed, the Huid pressure developed by the impeller 24 decreases. In response thereto, the piston 26 of the governor 22 moves downwardly to turn the shaft 21 in counterclockwise direction. As will be apparent from Figs. 3 to 8, the counterclock- Wise movement of the shaft 21 effects successive downward movement'of the rollers forY the several admission valves, effecting opening movement thereof in sequence.

Upon decrease in load and increase in speed, the fiuid pressure developed by the impeller 23 is decreased, in response to which the governor 22 moves the shaft 21 in clock- Wise direction. The cams on the cam shaft 21 thereupon control the relay of the several is to be understood that the invention is not Y so limited. Each valve may be brought to any desired position at each position of the cam shaft by shaping the cam member accordingly.

From the above description, it Will be seen that I have provided a mechanism which is readily adaptable to Widely varying applications. The rate and time of opening of each valve is readily determined by the shape of the cam surface.

lVhile I have shown my invention in but` one form, it Will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications Without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereon as are'imposed by the prior art or as are speciflcially set forth in the appended claims.

What I claim is:

1. The combination With a plurality of valves, of mechanism for operating the same comprising a fluid pressure relay for each valve, a housing for each relay, a cam shaft extending through said housings and having a cam thereon in each housing controlling the relay therein, and a fluid pressure relay for actuating the cam shaft.

2. The combination with a plurality of valves, of mechanism for operating the same comprising ay fluid pressure relay for each valve, a housing for each relay, a cam shaft extending through said housings and having a cam thereon in each housing controlling the relay therein, a crank arm on said shaft, and a fluid pressure relay connected to said crank arm for actuating the cam shaft.

3. The combination with a prime mover having a plurality of admission valves, of mechanism for operating the same comprising a fluid pressure relay for each valve, a housing for each relay, a cam shaft extending through said housings and having a cam Y thereon in each housing controlling the rethrough said housings and having a cam thereon in each housing controlling the relay therein, a crank arm on said shaft, and a governor responsive to the speed of the prime mover and connected to said Crank arm for actuating the cam shaft.

In testimony whereof I have hereunto subscribed my name this 25th day of November,

ANTHONY F. SCHWENDNER.

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