US1748326A

US1748326A - Hydraulic relay governor

Info

Publication number: US1748326A
Application number: US280692A
Authority: US
Inventors: Birmann Rudolph
Original assignee: Laval Steam Turbine Co
Current assignee: De Laval Steam Turbine Co
Priority date: 1928-05-26
Filing date: 1928-05-26
Publication date: 1930-02-25
Anticipated expiration: 1947-02-25

Description

vFeZS; 1930. R. BIRMANN v I 1,748,326

HYDRAULIC RELAY GOVERNOR Filed May 26.* 1928 2 Sheets-Sheet. 1

Patented Feb. 25, 1930 AUNIT- ED STATES RUDOLPH BIRMANN, OF TRENTON, NEW` JERSEY, ASSIGNOR v'.I.O DE LAVAL4 STEAM TURBINE COMPANY, OF TRENTON, NEW JERSEY, A CORPORATION OF NEW JERSEY 'HYDRAULIC RELAY covnrmon Application led May 26,

In an application filed by me August 6, 1927, SerialNo. 211,092, I setforth a governor valve mechanism in which the mechanical connection between the pilot valve and the piston for operating the motive iiuid admission or governor valve is replaced by hydraulic means, in such manner as to simplify the construction of the governing mechanism and make the locationy of the valve-'actuating piston independent of the location of the governor itself ;l the construction-also being one which 'has the desirable characteristics possessed by an isodromic governor whereby a regulation is. obtained that gives practically constant speed at any load between full load and no load. The invention isA shown as adapted to a mechanically operated speed governor, to a'speed governor of the hya draulic type and to a governor that is intendyed and adapted toy obtain a regulation that gives asubstantially constant v,olume.

' In the specific embodiment ofthe invention therein shown, after the main' valve for admitting pressure fluid to the turbine has fbeen operated, due to change of load,V to increase or decrease the volume of steam admitted to the turbine, the compensating sleeve that is movable to shut olf further How of pressure fiuid to the piston that operates the ao main valve is operated by a construction whoseoperation is dependent on thel pressure difference which exists momentarily between the lines that convey thepressure fluid lto and from such piston. In the present invention the compensating sleeve is operated directly by the pressurefluid iowing toward or from the piston, which mode of operation is found to have decided practical advantages. A

In the drawings, which show one embodiment of the invention applied to a mechanically operated speed governor:

Fig. 1 .isa side view of the governing mechanism and the connections therefrom to the governor valve and its actuating piston.v 45 Fig. 2 is a vertical sectional view of the governor proper, the pilot valve operated thereby,and the appurtenant parts embodying my invention.

The shaft a may be assumed to be the shaft 5 of aturbine or any other prime mover. Shaft 1928. Serialv No.' 280,692.

a drives the governor shaft c by any known means, such as by spiral gears b. Shaft o v late f supports, on

a ball race, a shaft g which, at its upper end,

" slides in a bearing plate .-k secured to a casing z' that encloses the parts described. Spring j isfconinedlbetween plate f and a plate g,

the latter being threaded on the end of a rlng q" enclosing the spring and rigidly secured -by means not shown) to disc d.

The centrifugalv governor comprises two semi-cylindrical weights lc, c, which are fulcrummed at m, melon the fiange of disc d and are adapted to be centrifugally actuated to swing out on their fulcrums.

The stem of the pilot valve 10 may be integral with shaft g, but it is preferable to connect them by a flexible joint n to dispense with the necessity of exact alignment between shaft g and the lpilot valve. v

A spring s is conned between a plate o p on the upper'end oshaft'g andl an adjusting nut p threaded in an annular flange 1' on casing z'.

The governor need not be more particularly described, as it is of a well known type and may be replaced by any other operable type of overnor. I

he pilot valve 10, provided with the

pistons

12 and 13, slides'in a sleeve 11 which itself is slidable in a valve casing or valve body yt mounted on casing z' and has ports communicating with

ports

14, 15 and 16 in the valve casing. The intermediate pressure port '15 is open to an oil admission pipe 17. Portsf14 and 16 are respectively connected, by means of

pipes

18 and 19, with the top and and bottom sides'of an operating piston 20, which controls the valve y for admitting pressure Huid to the turbine.

The upper end of the pilot valve sleeve 11 is provided witha piston 21, which works in al cylinder 22 formed in the upper end of the valve body t. Springs 23, 23 are confined between piston 21 and the end walls of cylinder 22. ,The piston is provided with f -a restricted orifice 24 to allow slow 'leakage of oil from one side of the piston to the other.

Assuming that the turbine is running under any load, pilot valve 10 with

pistons

12 and 13 will assume a position in relation to sleeve 11 as shown in Figure 2. This relation of parts represents the normal position to which the parts would tend to return after any change in governor action. It will be noted that the preferred arrangement will cause the upper edge of lower piston 12 and the lower edge of upper piston 13 to barely clear the ports in sleeve 11, while the upper end of piston 13 and the lower end of piston 12 should overlap by a small amount the ports in sleeve 11.

Assuming an increase of load, the turbine will tend to slow down andthe centrifugally actuated governor weights` le will move closer towards thecenter from the quiescent position shown in full lines in Figure 2 and will assume a new position as shown in dotted lines. Pilot valve 10, following the movement of the governor weightswill assume a lower position, thereby admitting working fluid (oil) under pressure through port 15, valve sleeve -11 and-port 16 to pipe 19 and thence to the bottom side of operating piston 20, thereby further opening governor valve y. The return flow of oil through pipe 18 and port 14 is split into two parts. One part passes direct through orifice 27. Another part is by-passedthrough by-p'assage 26 to the space above piston 21, forcing the latter down and displacing the oil below it, which escapes through byspassa'ge 25 and meets the main return low in port 14. The return oil outlowing through port 14 escapes through sleeve 11, space 3Q, hole 31, the interior of valve casing t, and`hole32 to the interior of casing i. The volume'ratio of the two flows through orifice 27 and passage 26 is determined by the ,size of the orifice 27 and. the degree to which needle valve 28 is throttled, which in turn determine the rate of movement of the compensating sleeve 11. The downward movement of sleeve 11 closes port 16 and shuts olf further flow of oil to the piston 20.

Immediately upon the opening of valve .by piston 20, as above described, the turbine receives a llarger volume of steam and increases its speed, causing governor, weights il: to assume their normal position and return-` i ing the pilotvalve to its normal position. At

the same time the oil pressure on opposite sides of piston 21 has become the same due to the flow of oil through opening '24, and piston 21 with sleeve 11 has been pushed upward by lower spring 23, returning sleeve 11 to` of the governing parts, consequently causing no permanent change 1n speed; resulting in an isodromic action of the governing mechanism.

Assuming a decrease of load, pilot valve 10 will move up, thereby admitting oil through port 14 and pipe 18 to the upper side of the operating piston 20, which moves down and more or less throttles the governor valve y. v The oil flow through port 14 is split into two parts, one Ipart passing through oriice 27 and going direct to pipe 18 and the 'other part by-passing this orifice and going through by-passage 25 to the space beneath piston 21, forcing up the latter and sleeve 11 and displacing the Huid above it which escapes through by-passage 26 and meets the main flow of oil through port 14 and pipe 18. The return. oil outowing through port 16 escapes downward through sleeve'll and iins 33 that afford a .guide for the lower end of the 's pilot and through opening 34 into the interior of casing z'. The upward movement of sleeve 11' closes port 14 and shuts oi further flow of oil to the iston 20. Immediately upon the throttling o valve y by piston 20, as above describedgfthe supply of steam to the turbine is decreased, causing the governor weights c to assume their normal position and return the pilotvalve to its normal position. At the same time the oil pressure on opposite sides of piston 21 has become the same, due to the flow of oil through opening 24, and piston 21 and compensating sleeve 11 have been sleeve 11 to normal position simultaneously with the return of pilot valve 10 to its normal position by the governor. It will thus be seen that the action of the governing mechanism caused by the vdecrease of load has caused the governor valve Ato be throttled without any permanent change in position of the governing parts, consequently causing no permanent change of speed and resulting in an isodromic action of the governing mechpushed downby upper spring 23, returning l ment of the generic invention disclosed in,

said application, the piston 21 and compensating sleeve 11 are dependent for their operation on the'momentarypressure difference which exists between

lines

18 and 19, whereas in the present construction the operation of piston 21 and sleeve 11 depends upon the flow through line 18 (or line 19) alone, which is found a simpler and more dependablemode of operation.

Like the invention of my earlier application, the invention isadapted to any kind of governor, such as a pressure governor, volume governor or speed governor used sep'- arately or combined. The latter may be of the mechanical (centrifugal) type or the pure hydraulic type which depends for its operation on variation in fluid pressure with variation in speed. The invention is also applicable to any kind of governor which depends for its operation on variation of fluid pressure with variation in volume. Not only may the pilot valve be actuated by a speed governor, or by a pressure governor, or by a diaphragm subjected to changev in pressure or temperature, or by other means, but the power piston may be adapted to any class of service. It may, fof example, control, instead of a prime mover, any mechanical element such as the grate of a Stoker or the stem of a valve. I do not herein claim the inventive features characterizing the governing mechanism set forth in my said prior application and described in the introductory part of this specifcation; the present invention being confined to the improvement as set forth in the appended claims. Y

Having now fully described my invention, what I claim and desire to protect by Letters Pat-ent is:

. 1. In a'governor for a machine, the combie nation with a driving element ofthe machine and a device controlling the operation of the machine, of fluid controlled means to actuate said device, meansl .providing a working fluid.

inlet and outlet and two passages for f low of working fluid toward and from said ,fluid controlled means, pilot valve mechanism comprising a valve and a free floating sleeve movable relatively one to the other and adapted .to be positioned to connect said fluid inlet with either of saidpassages and said fluid outlet with the other of said passages, means controlled from the driving element to actuate the pilot valve, means providing bypassages from one of said passages, and fluid actuated means adapted to operate said valve sleeve and to be actuated in one direction by inflowing working fluid by-passed through one of said by-passages and to be actuated in the otherI direction by outflowing working fluid by-passed through the other of said bypassages. v

2. In a governor for a machine, the combination with a driving element of the machine and a device controlling the operation` of the machine, of fluid controlled means to actuate said device, means providing a workingOfluid inlet and outlet and two'passages for flow of working fiuid toward and from said fluid controlled means, pilot valve mechanism comprising a valve and a free floating sleeve movable relatively one to the other and adapted to be positioned to connect said fluid inlet with 4either of said passages and said fluid outlet with the other of said passages, means controlled from the driving element to actuate the pilot valve, a piston adapted to actuate the valve sleeve, means providing bypassages from one of said passages, said bypassages communicating with opposite sides of said piston whereby the piston is moved in one direction or the other dependent on the direction of flow of the working fluid through the last named passage.

3. In a governor for a machine, the combination with a driving element of the machine and a device controlling the operation of the machine, of fluid controlled means to actuate said device, means providing a working fluid inlet and outlet and two passages for flow of working fluid toward and from said fluid controlled means, pilot valve mechanism comprising a valve and a free floating sleeve movable relatively one to the other and adapted to be positioned to connect said fluid inlet with either of said passages and said fluidoutlet with the other of said passages, means controlled fronm the driving element to actuate the pilot valve, one of said passages comprising two sections communicating througha restricted orifice, a piston adapted to actuate the valve sleeve, and means providing ley-passages from therespective sections of the last named passage, said by-passages communicating with opposite sides of said piston, one of said by-passages having means restricting its flow there-v through.

4. In a governor for a machine, the combinationwith aV driving element of the machine prising a valve and a free floating sleeve movable relatively one to the other and adapted to be positioned to connect said fluid inlet with either of said passages and said fluid outlet with the other of said passages, means controlled from the driving element to actuate the pilot valve, a piston adapted to actuate the valve sleeve, means providing bypassages from one of said passages, said bypassages communicating with opposite sides of said piston whereby the piston is moved in one direction on the other dependent on the direction of iiow of the working iuid through the last named passage, there being a' restricted orifice affording communication between opposite sides of said piston, and a tension device tending to restore said piston and valve sleeve to a median position.

5. In a governor for a machine, the com*- bination with a driving element of the mal chine and a device controlling the operation of the machine, of. fluid controlled means to actuate said device, means providing a working fluid inlet and outlet and two passages for iow of working fluid toward and from said iiuid controlled means, pilot valve mechanism comprising a valve and a free floating sleeve movable relatively. one tothe'other and adapted to be positioned to connect said luid inlet with either of said passages and said fluid outlet with the other of said passages, governing mechanism operable by the driving element upon a deviation from normal of the speed of said element and adapted when so operated to so actuate the pilot valve as to open communication between said inlet and one ofsaid passages and between said outlet and the other of said passages and thereby cause a tlow of working fluid adapted to operas'atesaid fluid controlled means and said device to effect a restoration to normal of the speed of said element, a piston movable with said sleeve, means providing by-passages from one of said passages to opposite sides 40 respectively of the piston and by means of which the working fluid traveling through one of said passages is adapted to move said piston away from normal position and thereby move said sleeve into osition to close communication between sai inlet and outlet and said passages, and means to returnl the'piston to normal position as the valve is returned -to normal position due to restoration to normal condition of said governing mechanism consequent upon said restoration to normal'of the speed of saidelement. Y In testimony of whichLdvention, Ihavef hereunto set my hand, atl-J enton, N. J., on n this 18 day of May. 1928.

' RUDOLPH: amm. l