US1551354A - Marine-type-ttjrbine speed governor - Google Patents

Description

. 1,551,354 J.' WILKINSON uknmn' TYPE TURBINE SPEED GOVERNOR .Filed Feb. 2. 1923 2 Sheets-Sheet 1 lnve nfLor": JamesWHKmson,

His Attbine g. I

Aug. 25, 1925.

J. WILKINSON MARINE TYPE TURBINE SPEED GOVERNOR Filed Feb. 2. '192: 2 Sheets-Sheet 2 Inventor:

JamesWiIKmson y r His Attorney- Patented Aug. 25, 1925.

UNITEDSTATES v 1,551,354 PATENT OFFICE.

JAMES WILKINSON, or LYNN, MAS-SACHUSETTSLASSIGNOR T0 GENERAL ELECTRIC OMPANY, A CORPORATION OF NEWv YORK. I

r MARINE-TYPE-TURBINE SPEED GOVERNOR.

Application filed February 2, 1923. Serial No. 616,480.

To all whom it may concern."

Be it known that I, J AMES WiLxrNsoN, a citizen of the United States, resid ng at Lynn, in the county of Essex, State of Massa-' chusetts, have invented certain new and'useful Improvements in Marine-,Type-Turbine Speed. Governors, of which the following is a specification.-

' The present invention relates to governing of the turbine to control said auxiliary source of fluid pressure.

" I accomplish the object of my invention by employing a fluid pressure responsive means which will open and close the throttle valve in response to changes in the speed of the turbine with a certain predetermined time delay before completing'the full operation of said valve. I

My invention can best be understood by first considering the conditions which are met in the application of turbines to ship propulsion. The problem of controlling the speed of a marine turbine when under normal operating conditions is not a serious one. as the turbine is normally under a load which remains constant as long as the pro- 'peller is submerged. There is, however, 'always a possibility of the load being thrown off the turbine by reason of a-broken: shaft, loss of the propeller or the propeller coming out of the water in a seaway or trough while cruising in rough weather.

It is this latter condition which my invention is primarily designed to meet. It will be seen that if the ship is traveling in a direction substantially transverse to the swells that the propeller will come out of the water in each seaway or trough. This is particularly true where the ship" is lightly loaded and when the sea is extremely rough. As the propeller comes out of the water the turbine will speed up andunless a trip mechaparts.

nism is provided will either run away or be subjected to severe strains when the propeller again submerges because it will suddenly take up the load under full steam. This is objectionable for: the reason that it' creates violent strains on the turbine and associated Under the above condition'the speed control mechanism now in general use will trip the'throttle valve and shut down the turbine thus leaving the ship. without propelling means at a time .when it is imperative to have the ship under power. With the above type of control it has been found necessary to keep a man at the throttle valve, whose' duty it is to open the same after each tripping when the propeller again submerges.

' With my invention I intend to accomplish the latter operation automatically in response to the speed of the propeller.

. V In the present'embodiment'of my invention I show a turbine having a pressure oilmg system. I proposeto use the lubricating medium of such a system for operating the pressure responsive means whichcontrols the throttle valve. This will not only insure a positive means for transmitting the forces from one correlated part to the other but in addition will provide against the turbine running without proper lubrication, as the throttle valve will close automatically upon failure of pressure "in the oiling system. -Additional novel details of construction and combinations of apparatus will be hereinafter described, and the novel features which I believe to be characteristic of my invention will be definitely indicated in the claims appended hereto. I

The features ofconstruction and mode of operation will be understood by referring to the'following description taken in connection with the accompanying drawings which showthe preferred embodiments of my invention. Fig. 1 is a plan view of a turbine driving a propeller through speed reducing gears and shows the relative location of the different parts of my invention as applied thereto; Fig. 2 is a diagrammatic view of the different parts i of my invention and shows their relation to each'othemFig. 3is I a partial sectional view of thespeed responview of the pilot valve shown in Fig. 3, and taken alongline BB; Fig. 6 is a sectional view taken from Fig. 3 along line CC; and Fig. 7 shows a modification of my invention wherein I employ a torsion device instead of the tappet arrangement shown in the other figures of the drawings. It also shows a sectional view of the pilot valve.

In the drawings a preferred embodiment of my invention is shown wherein I utilize the oil pressure of the turbine pressure oiling system to operate the speed controlling valve. lteferring to Figs. 1 and 2, my in vention comprises a valve 10 of the balanced pressure type mounted upon the steam chest 11 of the turbine 12 and in the main steam line 13. Attached to the valve 10 is a pressure cylinder 14 having a piston 15 mounted therein. The piston 15 is biased in a direction to close the valve by means of a spring 10 which spring represents any suitable means for rendering the valve self-closin The valve is opened against the spring action by admitting oil to the cylinder from the turbine oiling system through a pipe 17 which. conducts the oil from a pilot valve 18. The pilot valve 18 thus controls the oil sup ply to the cylinder 14 and is actuated by a tappet governor 19 which will be described in more detail hereinafter. In the drawing 1 show the tappet governor 11 mounted on the reducing gear casing 20 adjacent the end of one of the shafts. It should be under stood, however, that this tappet governor can be mounted in any convenient location where means to operate the governor are available, as for instance at the end of the turbine shaft. Connected between the pilot value 18 and the gear casing 20 I show the pipe 21 which conducts the oil under pres sure to the pilot valve 18 and from which the oil passes through the pipe 17 to the cylinder 14 or through the pipe 22 to an exhaust basin, depending upon the position of the pilot valve 18. I also provide in addition to the above an over speed emergency tripping device 23 which is of the usual type comprising a plunger 24 or other centrifugal responsive device mounted upon a rotating shaft 25 and adapted to strike a trigger 26 when a certain predetermined abnormal high speed is reached by the shaft 25, the latter being the main shaft of the turbine. The trigger 26 is movable when struck by the plunger 24 to release a plunger rod 27. At 21' is a spring which acts in a direction to force rod 27 downward when released from trigger 26. The plunger rod 27 is connected by a shaft 28 and a linkage indicated at 29, with a shaft 30 of pilot valve 18 in such a manner. that the clownward movement of plunger rod 27 causes the shaft 30 to be rotated. lVhen the shaft 30 is thus rotated it will close the pilot valve 1.8 and render it inoperative and thereby shut down the turbine. The connection between plunger rod 27 and shaft '28 is a lost motion connection of the usual type comprising a pin and slot which permits shaft 28 to be turned independently of rod 27 for actuating the valve 18 manually.

Referring now to Figs. 3 and 4, I show the pilot valve 18 having at one end the pipe 1.7 for conducting the oil under pressure to the cylinder 14 and against the piston 15 which operates the throttle valve '10. Entering and leading from the topof pilot valve 18 are pipes 21 and 22 which conduct the oil to and from the pilot valve 18 respectively. The pilot valve 18 is of the concentric sleeve type having a movable sleeve 31 which is capable of a reciprocating or a rotary movement. At one end of the sleeve 31 (see Fig. 5) four openings 32 are provided which align with four similar openings 33 in a stationary sleeve 34 surrounding the movable sleeve 81.

, On the other end of the movable sleeve 31 is a web 35 which extends diametrically across said sleeve .31 and engages a. slot 36 in the shaft 30 which is operated by the high speed emergency tripping mechanism. The slot 36 in shaft 3Q is made sufficiently deep to allow full axial movement of the sleeve 31 in response to the tappet speed governor which is operatively connected with said sleeve as will hereinafter appear, but at the same time it prevents any rotary movement of the sleeve 31 except that which is caused by the rotation of shaft 30. The valve arrangement is such that rotation of the shaft 30, as by the tripping of the emergency governor or manually, causes the openings 32 to be carried out of alignment with openings 33 thereby cutting off the oil supply from pipe 21 to the interior of sleeve 31 and to pipe 17 which last supplies the throttle valve operating cylinder 14. Sliding the sleeve 31 to the right from the position shown also serves to out on the oil supply from pipe 21 in a similar manner. With the above arrangement it will be seen that the pilot valve will operate in response to forces from two differentsources; one the speed governor proper and the other the emergency trip mechanism.

ld/hen the turbine is running the sleeve 31 is normally held in the open position shown, with openings 32 and 33 in registration, by means of a bifurcated lever 37which is journaled upon a stationary shaft 38 and mounted in a casing 38 surrounding the tappet governor 19.

The lower end of lever 37 is offset and has two tongues 39 and 40 projecting at right angles therefrom in twodifferent planes (see Fig. 6). The projecting tongues 39 and 40 respectively engage eccentric surfaces 41 and 42 of an eccentric governor weight 43. The eccentric governor weight 43 is pivotries of bell-cranks lever 37 will be practically centered over the end of shaft 44. The governor arrangement is such that at a predetermined speed above normal speed and below the speed at which the emergency governor is set to trip, the governor weight moves in a direction to carry sleeve 31 to the right as viewed in Fig. 3 slidably a sufiicient distance to cut off the oil supply from pipe 21.

Within the pilot valve 18 allow free movement of the shaft 30 and at the same time permit a predetermined amount of oil to flow therethrough, thus forming a restricted outlet for the oil. .Connected to valve 10 is an operating lever 48 for use in opening the valve. manually, and connected to shaft 30 of the pilot valve is a. crank lever 49 for actuating the pilot valve manually.

Referring now to Fig. 7, I show a modification of my invention wherein I dispense with the tappetgovernor described above and substitute therefor a speed governor in the form of a torsion responsive device.

In the drawing 50 is r a resilient shaft coupling of a known type comprising interleaving tongues projecting from flanges on the respective shaft ends and resilient means interposed in'the radial paths of said tongues. The two elements of this coupling move circumferentially relatively to each other by amounts proportional to the load, and associated with such elements is a se- (not shown) transmit an aXial movement to a ring'51 shown in the drawing. The essential thing is that ring 51 moves axially in response to 'load changes. I preferably employ a coupling 50 and torsion responsive mechanism, as shown in my Patent No. 1,359,853, dated November 23, 1920.

In this modification of my invention I use a pilotvalve 54 which operates to open orclose on axial movements only.

Cooperating with the ring 51 is a groovec wheel 52 whose'flanges engage the'ring- '51 and cause it to be moved in an axialdirectionin response to any axial displacement of the ring 51.

The grooved wheel 52 is mounted upon a shaft 53 and is free to rotate thereon. The shaft 53 is mounted in a pilot valve casing 56 and is attached to a valve sleeve which is open at both ends. Located on the valve sleeve 55 are a series of openings which align'with similar openings in the stationis a partition 47 which has an opening sufiiciently large to.

which ary lining sleeve 57 when the pilot valve is in the open position. Entering at the top of the pilot valve 56 is a pipe 58 which conducts the oil from the pressure source to the pilot valve 56 and leading from the bottom of the pilot valve 56 is a pipe 59 which carries the oil discharge to a suit able collecting basin or reservoir (not shown). l Vithin the pilot valve casing 56 is a partition 61 having an opening sufiiciently large to allow the shaft 53 freedom of movement and at the same time allow a predetermined flow of oil to pass therethrough from. the interior of. sleeve 55 to a discharge pipe 59. A pipe 6.0 is shown connecting the pilot valve 56 and the piston cylinder 14 of the main throttle valve 10.

The operation of my invention is as follows s To start a turbine equipped with my invention, the lever 48 mounted at the end of the throttle valve 10 is pulled to the left as shown in Fig. 2. This permits steam to 7 enter the turbine anl after being once started theturbine will be controlled automatically, as I shall .point out below. I also provide a crank-lever 49, as shown in Fig. 1, project ing from the pilot valve 18 for shutting down the turbine when a deliberate stop is desired. This crank acts independently of the energy tripping mechanism because, of the pin anl slot connection between rod 27 and shaft 28, and when operated by'hand rotates the valve sleeve 31 of the pilot valve 18 and shuts off the'fluid pressure supply to cylinder 14, thereby causing the throttle valvelO to close and thus stop the turbine.

Assume now that the turbine is running at normal speed and that the pressure-of the oiling system is constant. Under these conditions, th various parts of my invention will be in the positions shown in the drawing. Valve 10 is held open in response to pressure exerted upon piston 15 by the lubricating oil passing through the pilot valve 18 when in the position shown in Fig. 3. At, the same time a small quantity of oil will flow through the restricted opening 47 in the pilot valve to outlet pipe 22.

If now the speed of the turbine should become. excessive by reason of the propeller coming out of the water, theweight43 of i the tappet governor 19, will overcome the member 43, and since lever 37 is pivoted midway its ends, the upper end of lever 37 will move to the right and close the pilot valve 18,'thus shutting. off the supply of I fluid pressure 'to the cylinder 14. The spring 16 in the cylinder 14 will now cause the valve 10 to close and force the oil from' cylinder 14 through the restricted opening in member ot the pilot valve 18 from which it will flow to the oil reservoir through pipe 22.

As the valve 10 closes the steam supply to the turbine will be shut oil and cause the turbine to slow down and as a result the, weight of the tappet governor will then A!) return to its normal position in response to the force exerted upon it by the spring lG. This will cause the pilot valve 18 to open again and permit the pressure ot the lubricating fluid to be exerted upon the piston 15 and cause the valve 10 to open.

It will be seen from the above that such an arrangement will give a periodic opening and closing or the valve 10 in response to normal and abnormal speed conditions of the propeller respectively. lhese periodic operations of the throttle valve 10 can be made to correspond to such periods of time as are found desirable.

tssun'ie now that for some reason the above cycle oi? operation tails to occur and that the turbine continues to speed up to a dangerous speed as, for instance, the speed at which the em 0 ncy tripping mechanism operates. This will cause the plunger Q-l ot the emergency tripping device 23 to project from the shaft 25 because of centrifugal force. The plunger 24: will strike the trigger 26 which will release the plunger rod 27 and this will permit the shaft 28 to rotate in response to force exerted by spring 27, and through suitable levers also cause the shaft 30 of the pilot valve to rotate through an arc of approximately l5 which is sufiicient to close the pilot valve 18. This will shut oil the supply of fluid pres sure to the cylinder i l and, as described above, the throttle valve 10 will close and shut down the turbine. It will then be necessary to reset the emergency tripping device by hand before the-turbine can again be started, thus insuring a complete stopping of the turbine.

In the modification shown as Fig. 7 the operation of my invention is substantially the same as described above with the exception that instead of a tappet governor operating the pilot valve sleeve 31, I provide means to operate a similar valve sleeve 55 in response to differences in torque exerted upon two cooperating coupling flanges, one on the driving shaft and the other upon the driven shaft, which will transmit axial movement to the ring 51 and thus cause the valve sleeve to be'moved within the valve casing 56 because of its engagement through the grooved wheel 52 with the ring 51.

i hen the pilot valve of modification shown in Fig. 7 is in the position shown the oil under pressure will enter the pilot valve 56 through the pipe 58 and flow through the pipe 60 to the cylinder 14 in which it will exert pressure upon the piston 15 and hold the valve 10 open. At the same time a. small amount of oil will flow through the restri ted opening in the partition 61 of the pilot valve, to the oil reservoir through the pipe 59.

If new the propeller comes out of the Water, the variation in torque upon the twocooperating flanges will cause the ring 51 to move avially and move with it the grooved wheel 52. This will move the pilot valve sleeve 55 to the closed position and thus shut oil the supply of fluid pressure to cylinder 14. The piston 15 will then be moved by the spring 16 to close the throttle valve 10, the oil within the cylinder being forced out 01" the cylinder l l through pipe 60 and the restricted passage in partition 61 of the pilot valve to the outlet pipe 59.

nder normal conditions before the tur bine comes to a complete stop the propeller will again submerge and the torque responsive coupling will cause the ring 51 to move to the left and open the pilot valve, thus allowing the oil pressure to be again exerted upon piston 15. The piston will be moved by the pressure 01"" the oil to open throttle valve 10, whereupon steam will again be admitted to the turbine.

In this modification I show no emergency tripping means but it should be understood that such a means could be provided as shown in connection with the valve of Figs. 3 and at without departing from the cope of my invention.

It will be seen that in accordance with my invention in one embodiment thereof 1 provide a. balanced self-closing throttle valve in the motive fluid supply line of a turbine ant. means actuated by the pressure from the oiling system of the turbine, for iolding said valve open.

in connection with such an arrangement I provide a pilot valve between the oil pressure supply and the means for holding the throttle va ve open, the pilot valve being movable to cut oil the oil supply and permit the throttle valve to close.

To the pilot valve I connect a dual governing means comprising an overspeed emergency-trip governor which closes the oilot valve when a certain maximum allowable overspeed is reached by the turbine, and a second governor which is operative to close the pilot Valve only when the turbine is operzt'ug under load and suddenly-or momenta ly loses said load in part or wholly, the second governor normally functioning before the speed reaches the predetermined maximum at which the emer ency governor is set to operate.

The second governor may be such that it is responsive to o-verspeed according to the arrangement shown in Figs. 3 and 4, thus being indirectly responsive to loss of load or it may be directly responsive to loss of load according to the arrangement shown in Fig. 7, the result in either case being the same, that is, the throttle valve is permitted to close upon loss of load.

By utilizing the oil pressure from the tur' bine oiling system to maintain the throttle valve in the open position, a desirable safety feature 15 incorporated in the control means for the turbine, in that the throttle valve will be permitted to close and thus stop theturbine in case the oil supply fails. Other means for operating the throttle valve may, however, be utilized in connection with the dual governing means.

What I claim as new and desire to secure by Letters Patent of the United States, is 1. The combination with a prime mover having a valve mechanism, of means for regulating said valve mechanism comprising a cylinder, a piston therein, a sourceof fluid pressure connected to said cylinder, a valve for controlling admission of fluid from said source to said cylinder, a. speed responsive means'i'o-r operating said valve in one direction when the turbine exceeds its predetermined normal speed by a certain amount, and second speed responsive device for operating said valve in another direction when the turbine exceeds its predetermined normal speed by a still greater amount.

2. In combination with a prime mover having a valve mechanism, of a governor mechanism therefor comprising a cylinder and a piston therein, a conduit for supplying fluid pressure to said cylinder, means connected in said conduit for controlling the supply of fluid pressure, said means comprising a normally open valve capable of both axial and rotary movements, either of which movements serves to close the valve, a governor for moving the valve axially to control the turbine within certain limits and to open and close the auxiliary fluid pressure COIlClLHt in response to the speed of the and said governor being operative the valve when a certain normal exceeded and causmg the valve to turbine, to close speed is be open governor connected with the valve, said gov-.

at all other speeds, and a second valve, a second valve adapted to control said fluid pressure supply in such a manner that when said second valve is closed the throttle valve will be closed, and when opened the throttle valve will be opened, and means to operate said second valve comprising a tappet governor and a high speed tripping device each of which operate to close said second valve when the turbine exceeds predetermined speeds, the tappet governor op-. erating at a speed lower than that at which the tripping device operates and causing the valve to automatically reopen when the speed at which said governor operates is receded from.

The combination with a. prime mover having a motive fluid supply conduit connected therewith and aself-closing throttle valve in said conduit, of a fluid operated mopilot valve in said conduit, the pilot valve being movable between the open and the closed positions to etl'ect a corresponding operation of the throttle valve, independent control means for moving the pilot valve between said last-named positions, a governor for the turbine connected with one of said control means, said governor beingresponsive to certain abnormal operating condi tions of the turbine to effect a closing of the pilot valve, a second governor connected with the other of the control means, said governor being responsive to a certain predetermined speed whereat it operates to close the pilot valve, and means forming a leakageopening in the operating fluid con-- duit between the pilot valve and the motor.

6. The combination of an elastic fluid turbine having avalve for controlling the admission of motive fluid thereto and a. fluidactuated motor for the valve, of a pilot valve for controlling the flow of fluid to said motor, said pilot valve being movable bot-h axially and c-ircumferent-ially, a governor for moving said pilot valve axially to control the turbine within certain limits, and a. second governor which turns the pilot valve to control the turbine within other limits.

In witness whereof, I have hereunto set my hand this 30th day of- January 1923.

JAMES l/VIL'KINSON.

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