US954011A - Turbine-governing mechanism. - Google Patents

Description

E. E. ARNOLDL TURBINE GOVERNING MECHANISM. APPLICATION FILED APR.2, 1906. RENEWED APR. 20, 1909.

954,01 1 v Patented Apr. 5, 19.10.

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E. E. ARNOLD.

TURBINE GOVERNING MECHANISM.

, APPLICATION H'L-ED APR. 2, 1906. RENEWED APR. 20, 1909.

954,01 1 Patented Apr. 5, 1910.

3 SHEETS-SHEET 2.

INVENTOR ATTORNEY WITNESSES ANDREWE. murmur ca mom-umoerumm WASHINGTON, D. c.

E. E. ARNOLD. TURBINE GOVERNING MEGHANISM.

APPLICATION FILED 9mm, 1906. RENEWED APR. 20, 1909.

954,01 1 Patented Apr. 5, 1910.

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INVENTOR ATTORNEY mui iw a GRANANI c0. PNOTO-LITHOGRAPHERS. WASHINGTON. 0.1:

UNITED STATES PATENT OFFICE.

EDWIN E. ARNOLD, OF WILKINSIBURG, PENNSYLVANIA, ASSIGNOR'TO THE WESTING- HOUSE MACHINE COMPANY, A CORPORATION OF PENNSYLVANIA.

TURBINE-GOVERNING- MECHANISM.

Specification of Letters Patent.

Patented Apr. 5, 1910.

App1ication filed April 2, 1906, Serial No. 309,491. Renewed April 20, 1909. Serial No. 491,196.

To all whom it may concern:

Be it known that I, EDWIN E. ARNOLD, a citizen of the United States, and a resident of WVilkinsburg, in the county of Allegheny and State of Pennsylvania, have made a new and useful Invention in Turbine-Governing Mechanism, of which the following is a specification.

This invention relates to elastic fluid turbines and more particularly to governing means for such turbines.

Elastic fluid turbines are ordinarily provided with extremely sensitive speed governors or controlling devices which operate in conjunction with a more or less complicated valve-operating mechanism in proportioning the amount of motive fluid supplied to the turbine. The valve-operating mechanism is ordinarily controlled by the governor through a fluid or electrically actuated relay device and, while it is ordinarily reliable and accurate in operation, it is expensive and diflicult to build.

The object of this invention is the production of a governing mechanism for turbines of simple construction and extremely sensitive and effective in operation.

A further object is the production of a mechanically-actuated valve-operating mechanism which is adapted to proportion the flow of motive fluid to the turbine in accordance with the load demand.

These and other objects I attain in a turbine embodying the features herein described and illustrated.

In the drawings accompanying this application and forming a part thereof, Figure 1 is a longitudinal section of a turbine embodying my invention; Fig. 2 is a side elevation of the valvebperating mechanism included in my invention; Fig. 3 is a section along the line 4:4= of Fig. 2; and Fig. 4 is a detail of the apparatus included in my invention.

The turbine illustrated as embodying my invention is of the multi-stage type and comprises a rotor element 5, inclosed within a stationary casing 6 and mounted on a shaft 7, which is journaled in suitable bearings. The casing is provided with a primary admission port 8, which admits motive fluid to the initial or high-pressure stage of the turbine, and a secondary port 9, which admits motive fluid to a secondary or lowpressure stage of the turbine. The primary admission port is provided with a double beat puppet valve 11, which controls the admission of motive fluid to the turbine, and the secondary admission port is provided with a similar valve 12, which is adapted to by-pass a portion of the motive fluid supplied to the low-pressure stage through the port 9.

The valve-operating mechanism consists of a series of levers which is operated by an eccentric and is under the control of a speedresponsive governor 13. The arrangement is such that the primary valve 11 will periodically admit regulable amounts of motive fluid to the turbine while the turbine is operating under light or normal loads; for heavy and excessive loads the bypass valve 12 begins to open periodically and admit regulable amounts of motive fluid to the low-pressure stage of the turbinethrough the port 9.

The primary valve 11 is provided with a valve casing 14, the interior passages of which communicate with a main fluid-supply pipe 15 through a passage 16, the valve chamber of the secondary valve 12 through a passage 17 and directly with the primary inlet port 8. The valve 11 is provided with a ri idly-connected valve stem 18, which exten s through a suitably-packed gland 19 located in the casing 14, and is rigidly connected to a cam-actuated housing 21. The housing 21 comprises a base piece 22, to which the valve stem 18 is rigidly mounted, and a top piece 23, which is connected to the base piece by suitable bolts 24. A rod 25, rigidly connected to the top piece 23, extends through suitable ways formed in the supporting casing 26 of the valve-operating mechanism and is provided with a rigidlymounted piston 27 which operates in a cylinder 28 formed integrally with the casing 26. The piston 27 is provided with a cylindrical extension 29 which is adapted, for certain positions of the piston, to close a cylindrical port 30 formed in the casing and communicating with the cylinder 28. The piston 27, in conjunction with the cylinder 28, performs the function of a dash or gag pot during the reciprocations of the valve 12.

The casing 26 is provided with suitable bearings 31 and 32 in which cam-actuating levers 33 and 34 are respectively journaled. The cam-actuating levers each comprise a hub portion 35, which is provided with an arm 36 and a cam 37. The cams-of the respective levers are located adjacent to each other and are arranged to contact with the top piece 23 of the cam housing 21 and to open the valve 12 by raising the housing.

A shaft 38 extends through the center of the hub portions of the levers 31 and 32 and is rotatably mounted therein. A tripping lever 41 is rigidly mounted on the shaft 38 and is provided at its free end with a rotatably-mounted pin 42 on one end of which a hook 43 is keyed and on the other end a releasing finger 44, which is adapted to contact with a cam 45, rotatably mounted on the shaft 38.

The tripping lever 41 is rovided with a jaw 48 to which an eccentric rod 47 is pivotally connected. The eccentric rod is reciprocated by an eccentric 46, which is driven by the turbine shaft through suitable gears and oscillates the tripping lever 41. The

cam 45 is moved to different positions about,

the shaft 38 by a governor 13 through the agency of a system of links and levers. The hook 43 is adapted to raise the valve 11 predetermined amounts during the oscillations of the lever 41 by seizing the end of the arm 36 of the cam-actuating lever 33 and carrying it through a portion of its travel.

The amount of the valve opening, or the are through which the arm 36 is carried by the hook, is determined by the positions of a trip surface 51 of the cam 45 which is arranged to occupy definite positions about the shaft 38 corresponding to the difierent speeds of the turbine and to trip the hook 43 through the agency of the releasing finger 44, thereby proportioning the amount of port opening in accordance with the load demand. The cam 45 is provided with an arm 52 to which a rod 53 is pivotally connected; the rod is connected to an arm 54 of a bell crank 55 which is moved to different positions about its fulcrum 56 by a governor-actuated sleeve 57.

The governor 13, which is somewhat dia-- grammatically shown in the drawings, consists of balls 58, pivotally mounted on brackets 29 carried by a rotatable standard 61 and connected to the sleeve 57, which is loosely mounted on the standard in such a way that the sleeve will occupy certain positions along the standard for certain speeds of the turbine.

The operating surface of the cams 37 of the levers 33 and 34 is so arranged that the valve will be opened rapidly at the beginning of the stroke of the eccentric rod 47, thereby overcoming the tendency of the motive fluid to wire draw and throttle. A spring 62 is mounted in the cylinder 28 and is adapted to close the valve 11 when the hook 43 releases the cam-actuating lever 33.

The arrangement of the piston 27 and the cylinder is such that the valve will be moved rapidly downward by the spring until the extension 29 enters the port 30 when the confined air below the piston will check the action of the spring and the valve will seat gentlydue to a restricted opening 80 which communicates with the cylinder.

In order that the forward and backward strokes of the eccentric may be utilized in opening the valve 11, a valveoperating mechanism, similar to the one described but oppositely positioned, is located at the other end of the shaft 38 and is adapted to opcrate the cam-actuating lever 34. The lever 63 corresponds in its functions to the lever 41 and is provided with a hook 64 and a releasing finger 65 which are rigidly mounted on a rotatably-mounted pin 66. The hook 64 is adapted to seize the arm 36 of the camactuating lever 34, which corresponds to the lever 33 and is provided with a cam 37, as before described. The cam is adapted to, open the valve 11 during the upward movement of the hook 64 and the lever 63. A cam 67 is rotatably mounted on the shaft 38 and corresponds to the cam 45 and is adapted to contact with the releasing finger 65 and certain positions of the lever 63. The cam is provided with a tripping surface 68 which is moved by a rod 69 which is connected to an arm 70 of the bell crank 55 to different positions about the shaft 38 which correspond to the different positions of the tripping surface 51 of the cam 45.

The bypass valve 12 is provided with a valve-operating mechanism similar to that of the valve 11 and is adapted to open and admit motive fluid to the low-pressure stage of the turbine when the valve 11 is open a maximum amount. The valve is provided with a valve casing 72 inclosing a valve chamber 7 3, which communicates with the interior of the valve casing 14 through the passage 17. The valve is provided with a valve stem 74 which is actuated by a valve actuating mechanism similar to the primary valve mechanism.

In the drawings only half of the operating mechanism is shown for the sake of clearness, but, like the primary valve, it consists of two cam-actuating levers, two tripping levers and two governor-controlled cams, each set being mounted at either end of a pin 75 and adapted to operate in conjunction with a cam-inclosing housing 76 in opening the bypass valve 12. The governor-controlled cams are connected by a rod 77 to their corresponding cams of the primary valve-actuating mechanism and are so arranged that the secondary valve operating mechanism is rendered inoperative in actuating the valve 12 until the primary valve is admitting a maximum amount of motive fluid.

The operation of the apparatus is as follows: During light loads on the turbine the cams and 67 occupy such positions that the hooks 43 and 64 raise the valve 11 small amounts during the reciprocation of the cocentric rod 47. As the load on the turbine increases, the cams 45 and 67 are moved by the governor to such positions about the shaft 38 that the periodic port opening of the valve will be increased in amount and duration until at some predetermined load 011 the turbine (about full load), the governor-controlled cams are moved to such a position that their respective tripping surfaces do not contact with the releasing fingers 44 and 65 and the valve 11 does not close during the oscillations of the shaft 38 but reciprocates between a half and maximum port opening. The arrangement is such that about the time the valve 11 is supplying a maximum amount of motive fluid to the turbine, the valve 12, through the agency of its respective governor-controlled cams, begins to admit motive fluid periodically to the low-pressure stage of the turbine and the arrangement is such that as the turbine slows down the governor-controlled cams will be moved to such positions that the periodic port opening of thesecondary valve will increase to correspond with the decreased speed of the turbine until at some predetermined low speed the secondary valve ceases to close but oscillates between a half and maximum cut-off.

Having thus described and illustrated my invention, What I claim as new and useful and desire to secure by Letters Patent, is:

1. In an elastic fluid turbine, a fluid admission valve, an operating mechanism therefor comprising a housing mounted on the stem of said valve, a cam located within and engaging said housing to operate said valve, an oscillating hook operating to actuate said cam, and means, dependent on the speed of said turbine, for controlling the operation of said hook.

2. In an elastic fluid turbine, a fluid admission valve, a housing mounted on the stem of said valve, a cam located within and actuating said housing to open said valve, a reciprocating hook for operating said cam, and a governor actuated release cam for controlling the operation of said hook.

3. In an elastic fluid turbine, in combination with the primary and secondary valves thereof, a valve operating gear for each of said valves, a single eccentric for actuating said gears and pulsating said valves, and means, dependent on the speed of the turbine, for controlling the operation of said valve operating gears.

4. In an elastic fluid turbine, a primary and a secondary valve, an actuating hook for each valve, a single eccentric actuating said hooks and speed responsive means for controlling the operation of said hooks.

5. A fluid admission valve and an operating mechanism therefor comprising a cam actuated housing on the stem of said valve, a cam for actuating said housing, a hook for operating said cam, means for operating said hook and a timing device for controlling the operation of said hook.

6. A fluid admission valve and an operating mechanism therefor comprising a camactuated housing secured to the stem of said valve, two cams for actuating said housing, an oscillating hook for actuating each cam and a single eccentric for actuating said hooks.

7. A fluid admission valve and a valveoperating mechanism therefor comprising the valve stem of said valve, means for positively actuating said valve stem, oppositely actuated oscillating hooks for engaging said means, an eccentric for operating said hooks and a timing device for controlling the operation of said hooks in engaging said means.

In testimony whereof, I have hereunto subscribed my name this 31st day of March,

EDWIN E. ARNOLD.

Witnesses:

CHARLES W. MoGHEE, R. P. MOINTYRE.

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