US1183921A - Governing mechanism for fluid-pressure turbines. - Google Patents

Description

c. R. WALLER & P. A. PETERSON. GOVERNING MECHANISM FOR FLUID PRESSURE TURBINES- APPLICATION FILED FEB- 7, 193- 1,183,921. Patented May 23,1916.

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c. R. WALLER & P. AI-PETERSON. GOVERNING MECHANISM FOR FLUID PRESSURE TURBlNES. APPLICATION FILED FEB. 17, I913.

Patented May 23,1916.

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unirni) STATES PATENT OFFICE.

CARL RICHARD WAL R am P R Anvil). Pn'rn nson, or TRENTON, NEW annsEY, AssIeNoR-s 'ro DE LAVAL STEAM TURBINE COMPANY, on NEW YORK, N. Y.,, A

CORBORATIONY on NEW JERSEY.

'GOVERNING MECHANISM FOR FLUID-PRESSURE 'IURBINES.

Specification of Letters Patent.

Patented May 23, 1916.

, Application filed February 17, 1913. Serial No. 748,880.

To all whom it may concern:

Be it kno-wnthat we, CARL RICHARD VVAL LER, a citizen of the United States, and PER ARVID PETERSON, a subject of the King of Sweden, both residents of Trenton, in the county of Mercer and State of New Jersey, have invented certain new and useful Improvements in Governing Mechanism for Fluid-Pressure Turbines, of which the fol lowing is a specification.

'Our invention relatesv to improvements in governing mechanism for fluid-pressure turbines, particularly steam turbines, and comprises fluid-pressure-operated, governorcontrolled means for operating a plurality of structurally separate valves and for operating such valves in succession; that is to say, for opening the valves one after another, in a predetermined order, and for closing them in reverse order.

Other features of our invention will be pointed out hereafter.

The objects of our invention are to improve and simplify governing mechanism of fluid-pressure motors generally, and particularly of steam turbines, to render the governing mechanism readily adaptable to motors of widely different designs, to provide simple mechanism for opening and closing a plurality of valves in succession, to

, provide means whereby a single governor may control the movements of such valves with a minimum of work done by the governor itself, to avoid the use of auxiliary devices for holding one or more of the valves open during the starting up of the motor, and generally to make the governing and valve operating mechanism simple, easy to manufacture, easy to maintain, sensitive and reliable.

We will now proceed to describe our invention with reference to the accompanying drawings, illustrating, more or less dialgrammatically, mechanism embodying our invention, and will then point out the novel features in claims. 3

In the drawings: Figure 1 shows diagrammatically andin part in elevation and in part in vertical section, a governing mechanism embodying our invention and comprising two valves arranged to be opened and closed successively. Fig. 2 is a plan view of the levers shown inFig. 1.

Fig. 3 is a diagrammatic elevation and partial section showing the control of three valves in accordance withour invention, two of the valves being shown open and one closed. Fig. 4: showsa plan view of the parts shown in Fig. 3. Fig. .5 is a view similar to Fig, 3, but showing one only of the valves open. I

In mixed pressure turbines, particularly turbines in which thelow pressure stage is lntended to be operated by the exhaust steam of a reciprocatingengine, or by other steamwhich is to be regarded, relatively, as waste steam, it is. usually sought to carry as large a proportion of the load as possible by such low I pressure, or, relatively speaking, waste, steam, high pressure steam being adm tted only atsuch times and in such quantities as maybe necessary to carry the load on the turbine, and to maintain the desired speedof the turbine. The arrangement shown in Fig. 1 is designed to operate in this manner.

In Fig. 1, numeral 1 designates the casing of a low pressure valve and numeral 2the casing of a high pressure 'valve. 3 desi nates the inlet chamber and 4 the outlet chamber of the low pressure valve, and 5 the inlet chamber and 6 the outlet chamber of the high pressurevalve. The valves proper, of whlch 7 is the low. pressure valve and 8 the high pressure valve, are double balanced puppet valves, the low pressure valve, 7, openlng downward for a reason to be explained hereafter, while the high pressure valve, 8, opens upward, in the particular arrangement shown. 12 designates a suitable centrifugal governor for controlling the operation of the valves in the manner hereinafter described. a The stem 14 of the low pressure valve 7 is: suitably guided'and is provided at its upper-fend with a piston 15 working in a pressure cylinder 16 mounted upon the bonnet 17 of the valve casing 1. The stem 18 of the high pressure valve 8 is similarly guidedand is provided at its upper endwlth a piston 19 working within a pressure cylinder 20 mounted on the top of the bonnet 21 of the high pressure valve casing. Similar pilot valves 22 and 23 supply fluid .under pressure to these pressure cylinders, 16' and 20 respectively, for the operation of valves, 7 and 8. These pilot valves in the construction shown, are of the piston type. Pilot valve 22 comprises four valve pistons, .24, 25, 26 and 27, controlling the flow from supply pipe'28 to one or the other of pipes 29 and 30 leading to the lower and upper sides of pressure cylinder 16 respectively, and controlling the discharge of fluid from the cylinder 16 through pipes 29 and 30. Such pilot valves being well known, it is considered unnecessary to describe the pilot valve indetail. .Pilot valve 23 comprises a similar arrangement of valve pistons controlling the supply of fluid under pressure from supply pipe 31 to either of thetwo pipes 32 and 33 leading to the lower and upper sides of pressure cylinder 20, respectively. For operating these pilot valves, governor l2hasxconnected to it a lever 31 pivotally connected at35 to another lever 36 connected at 37 to the stem 14 of the low pressure valve 7 lever 36 having a fulcrum at 38, and the stem 39 of pilot valve 22 being pivotally connected to lever 31 at 1 40. 7 Governor. 12 has also connected to it a lever 41 having a fulcrum at 412 and pivoted at 43 toalever Mcto one end of which the stem 4150f the pilot valve 23 is pivotally connected at 46; while the other end of said 1 lever 4a is pivotally connected to the stemv 18 of the valve 8 at e7. v v

In Fig. 1 the pilot valves are shown in positions which they would occupy when the turbine whichythey control, and which drivesthe governorl2, is in operation, these pilot valves being in such position that the low pressure valve 7 is wide open and that, with any momentary decrease in speed of the governor 12, the valve pistons connected i ,to the stem .45 of pilot valve 23 will open communication betweensupply pipe 31 and pipe 32 and will open pipe 33 to discharge, so causing piston 19 to open valve 8. Similarly, if the speed of the governor should ,rise slightly, the valve pistons of the pilot valve 22 will be raised, to an extent sufiicient to connect pipes 28 and 29, and to connectpipe 30 to discharge, so causing piston 15. to rise slightly and partly close valve 7.

-- Owing to the connectionof lever 36 to valve stem 14, and to the connection of lever 14 to valve stem 18, any movement of one of the pilot valves such as causes the corresponding main-valve-operating piston to move, re-

, sults in the immediateyreturn of that pilot valve to closed position,unless the'governor be still changing the position of the corresponding lever, 3 1 or 40. Consequently the mechanism shownis capable,

of making intermediate closed adjustments of said valves. The valve pistons of the two pilot valves have room for such overtravel that pilot valve 23 does not cause the high pressure'valve 8 to openuntil valve 7 is wide open, or nearly so and correspondingly not merely of closing and opening the valves 7 and 8, but

that, upon decrease of load, valve 8 is closed completely before any material closing of valve 7 begins. I

When low pressure main valve 7 is opened to an extent to supply low pressure steam to practically the maximum extent possible under the then existing circumstances to the turbine, and the governor 12 causes the high pressure main valves 8 to open, such opening of the main valves 8 may be accompanied by furthermotion of the low pressure main valves 7 in the direction of opening (which further motion of the main valve 7 will not, however, under such conditions, cause anyfurther increase in rate of flow of the low pressure steam) in which case there will be no corresponding over-travel of the low pressure pilot valve 22, since the motion of the main valve 7, transmitted through the follow up connections 3635-34: to the low pressure pilot valve 22 will preclude such over-travel of pilot -valve.22; or, alternatively, the low pressure main valves 7 may be arrested in their Wide open position, by means of a stop 7, in which event as the valves 8 open the low pressure pilot valve 22 effect on the low pressure main valves Both .arrangements are practical.

As previously stated, valve 7 opens by a downward movement. The reason for this arrangement of said valve is as follows: Pressure is usually maintained in the supply pipes 28 and 31, leading to the pilot valves,

by a suitable pump driven by the turbine or other motor which the main valves 7 and 8 control. Since this pump will not produce any material pressure in the pipes 28 and 31, when the turbine or other motor is at rest, or until such turbine or other motor has begun to turn over at considerable speed, if the valve 7 opened upward it would be necessary to provide auxiliary means for imparting pressure to the fluid in pipe 28 to open said valve 7 for starting, or else to provide other means for raising said valve ,7 and holding it open until the pump had reached a speed sufiicient to produce the pressure in pipe 28 required to open said valve 7 still farther or to hold it open. But with the valve 7 arranged to open downwardly as shown, such valve will be open normally when the motor is at rest and when such motor is being started, and valve 7 will be closed only when, through slight excess of speed, the governor 12 operates to close it.

The governing arrangement shown in Fig. 1, besides being applicable to mixed pressure turbines, is applicable to multistage turbines in which steam or other working fluid is supplied, normally, by one valve, 7 for example, to the highest pressure stage, and live steam is admitted through another valve, 8 for example, to an intermediate stage, when this is required by overload conwill over-travel without, of course, any

ditions. The supply of live steam to an intermediate stage to take care of overloads is in itself well known, and therefore we do not deem it necessary to illustrate particularly the application of the governing mechanism of Fig. 1 for such use, but merely mention the fact that the governing mechanism shown is applicable to such use, in order that it will be understood that it is not essential that valve 7 control steam of one pressure and valve 8 control steam of another pressure. Both valves may control steam of the same pressure. p

The governing mechanism embodying our invention is also applicable to the control of more than two valves. This is illustrated in Figs. 3, 4, and 5, wherein numeral 12 designates, as in Fig. 1, a suitable governor, numerals 48, 49 and 50 designate valves to be controlled by that governor, numerals 51, 52

and 53 designate suitable fluid pressure motors (cylinders and pistons) for ad usting said valves 48, 49 and 50, respectively, and

numerals 54, 55 and 56 designate suitable pilot valves for controlling the motors 51, 52 and 53, respectively. The pistons of these motors 51, 52 and 53 are connected, respectively, to levers 57, 58. and 59 to which the stems of the several pilot valves are also connected, and said levers 57 58 and 59 are connected to a lever 60 operated by the governor 12 in such manner that when lever 16 moves, in one direction or another, the levers 57, 5S and 59, all move; but the positions of the pilot valves with respect to said levers 57, 58 and 59 are such that, starting with all the main valves closed, movement of the governor lever 60 operates pilot valve 54 to open valve 48 first, and further movement of the governor lever is required to open valve 49, and still further movement of the governor lever is required to open valve 50.

61, in Fig. 1, designates a dash pot connected to a projecting portion of lever 41 and serving to make the motions of the pilot valves and governor somewhat gradual, so avoiding too sudden changes of speed or valve adjustment. The construction of these dash pots is well known and therefore it has not been deemed necessary to illustrate the internal construction thereof.

What we claim is 1. A governing mechanism for fluid-pres sure motors comprising a single speed governor, a plurality of main valves to be adjusted thereby, and each provided with a fluid-pressure motor for operatlng 1t, separate pilot valves for said valve-operating motors, and levers connecting said governor to said pilot valves and to the main valves, such levers arranged to restore each pilot valve upon the movement of the corresponding main valve resulting from a governorcaused movement of such pilot valve, the pilot' valves arranged, one for over-travel nected to each other,

while its .main valve is closed, another for over-travel after its main valve: is well open, whereby one of sald main valves does not open until the other main valve is well open,

valve consequent upon governor-caused movement of the corresponding pilot valve, and that one of said'main valves opens after the other main valve is well open and closes before such other main valve closes,..that main valve which opens first being acted upon normally by a force tending to hold it in open position, whereby such valve will be open when its corresponding valve-actuating motor is not holding it in closed posltion.

separate pilot valves for 3. A governing mechanism for fluid pressure motors comprising a single speed governor, two main valves to be adjusted thereby, and each provided with a fluid-pressuremotor for operating it, separate pilot valves for said valve-operating motors, two levers for connecting the governor to one of said pilot valves, such levers pivotally connected to each other and one connected to the gov; ernor and pivoted at fixed point, the other connected to said pilot valve and to the main valve controlled by that pilot valve, and two other levers for connecting the governor to the other said pilot valve, such last mentioned levers pivotally connected to each other, and one of them being connected to the governor and to the corresponding pilot valve, the other being pivoted at a fixed point and connected to the main valve controlled by that pilot valve.

4. A governing mechanism for fluid-pressure motors comprising a single speed governor, two main valves to be adjusted thereby, and each provided with a fluid-pressure motor for operating it, separate pilot valves for said valve-operating motors, two levers for connecting the governor to one of said pilot valves, such levers pivotally connected to each other and one connected to the governor and pivoted at a fixed point, the other connected to said pilot valve and to the main valve controlled by that pilot valve, a dash pot connected to the first of said two levers, the governor to the other said pilot valve, such last mentioned levers pivotally conand one of them being connected to the governor and to the corre- 80 upon movement of thecorresponding mam pilot valves,

sponding pilot valve, the other being pivoted at a fixed point and connected to the main valve controlled by that pilot valve.

5. Agoverning mechanism for fluid-pressure motors comprising a single speed governor, two main valves to be adjusted thereby, and each provided with a fluid-pressure motor for operating-it, separate pilot valves for said valve-operating motors, two levers for connecting the governor to one of said such levers pivotally connected to each other and one connected to the governor and pivoted at a fixed point, the other connected to said pilot valve and to the main valve controlled by that pilot valve, and two other levers for connecting the governor to the other said pilot valve, such last mentioned levers pivotally connected to each other, and one of them being connected to the governor and to the corresponding pilot valve, the other being pivoted at a fixed point and connected to the main valve controlled by that pilot valve, the first of such main valves being arranged to open upward, and the second of such main valves being arranged to open downward.

6. A governing mechanism for fluid pressure motors, comprislng a single speed governor, a plurality of main valves to be adjusted thereby, and. each provided with a fluid-pressure motor for operating it, separate pilot valves for said valve-operating motors, and means, including follow-up means, connecting said governor to said pilot valves and to the main valves, such connecting means arranged to restore each pilot valve upon the movement of the corresponding main valve resulting from a governor caused movement of such pilot valve, one of such pilot valves arranged for over-travel after its corresponding main valve has reached its limit of intended movement and while the other main valve is in position for adjustment by the governor.

7. A governing mechanism for fluid pressure motors comprising a single speed governor, high pressure and low pressure main valves to be adjusted thereby, and each provided with a fluid-pressure'motor for operating it, separate pilot valves for said valve operating motors, means, including followup means, connecting said governor to said pilot valves and to the main valves, such connecting means arranged to restore each pilot valve upon the movement of the corresponding main valve resulting from a governor-caused movement of such pilot valve, the high pressure pilot valve arranged for over-travel while the high pressure main valve is closed, and while the low pressure main valve is in position for adjustment by the governor.-

In testimony whereof we have signed this specification in the presence of two subscribing witnesses.

CARL RICHARD WALLER. PER ARVID PETERSON.

\Vitnesses A. E. ROBINSON, FRANK W. KENNEDY.

I copies otthis patent may be obtained for five cents each, by addressing the Commissioner of ratents,

i 1 Washington, D. G.

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