US1112394A

US1112394A - Speed-regulating device.

Info

Publication number: US1112394A
Authority: US
Inventors: Carl G Sprado
Original assignee: Allis Chalmers Corp
Current assignee: Allis Chalmers Corp
Priority date: 1910-11-23
Filing date: 1910-11-23
Publication date: 1914-09-29
Anticipated expiration: 1931-09-29

Description

o. Gg symb@ SPEED REGULATING- DEVICE. APPLICATION UJED NOV. Z 1910.

PWME'MEVE gdb STATES PATENT FFICE.

@domi (fr. SPG, F MILWAUKEE, WISCONSIN, SSIGNOR, BY MESNE ASSIGNMENTS,

ill@ ALPm-CHLMERS MANUFACTURING COMPANY, A CORPORATION OF DELA- vva nn srniw-REGULATING nnvrcn. N immense. Srifition 0f Letters Patent Patented Sept. 29, 191er. Application led November 23, 1910. Serial No.- 593,795. @o all: whom it may concern: and also against the lower surface of a ca it known that I, CARL G. SrRADo, a citizen of the United States, residing at Milvi/anime, in the county oi Milwaukee and .State or' l1Visconsin, have invented a certain new and useful improvement in Speed-Reg'- uleting Devices, or" which the following is a specillcation. D

This invention relates to improvements 1n the construction of predetermined speed regulating 4devices for rotating shafts espeoi'ally those of prime movers, such as steam turbines, gas engines, reciprocating steam engines, or other similar power generators.

.'.lhe object of the invention is to provide such a predetermined speed regulating device which is sensitive in its operation, thus permitting the speed of the shaft to be regulated within small limits to any predetermined speed.

d. clear conception of one embodiment of the .invention can be obtained by referring to the accompanying drawing which shows theregulating device applied to a steam. turine es prime mover.

The single ligure of the drawing is an elevation oi the device partly in section.

.The prime mover l, which may be either a steam turbine, gas engine, reciprocating steam engine, or other rotary device, has a main shaft lei to which an eccentric l5 is direct connected. The eccentric strap 18 on he eccentricjo, is adapted to reciprocate he piston lhof a compressor or pump 16. T e pump liis provided with'suitable inlet valve 2O and discharge valve 2l, which are shown diagrammatically as flap valves in the gure. The suction pipe 19 which enters the pump 16, leads from a suitable source of fluid supply not shown.

The high pressure discharge pipe 23 from the pump 16 has a "l" connection from which a branch pipe extends to the bottom of a high pressure reservoir 29.. he top of the interior of the reservoir 22 constitutes an air chamber 33.

second 'i' connection in the high prcssure pipe 23 provides for a branch pipe connecting to the interior chamber 13 formed in t e regulator casing 8. The plunger or piston l?. carried at the lower end of the rod l0 is adapted to reciprocate Within thc casing 8 and is subjected to the pressure within the chamber 13.

against the upper surface of the piston 12 which has screw thread tor maintaining rnoted that with the he spring l1 coactsv coaction casing 8. he cap may be made adjustable so as to vary the compression in the spring ll il so desired.

e upper end of the nected by on some stationary support. opposite overhanging end of the lever 7 is to the upper end of the throttle valve stem 9 by means of a pivot 5. The lower end ofthe throttle valve stem 9 carries a throttle valve 3 which is adapted to from the adis a simple disclosure of one ing this connection. tion may lead speed of the means of malr- However, this connecto' any device `or varying the prime mover. Thus far described the control system contemplates inlet of Huid at a rate proportional to the speed of the prime mover. It is an essential feature of this .invention to provide other means contemplating outlet Vof lthe same fluid at a predetermined and any means for doing this might he used suchffor instance, fluid meter running constant speed maintained so by pendulum control- The means illustrated herein outlet rate for the fluid discharging the fluid at stunt pressure.

1s a constant orifice a substantially con- The specific means comvalve delivering to a discharging through an orifice;

tank 28. Th lve piston 26 is downwardly by a spring 25, the compression of which spring is adjustable by means of a hand wheel 27 and screw. he piston 26 is .ree to rise and fall within a corresponding bore formed in the valve casing. p It Will be construction of piston as s own, the pressure upon the bottom sur- .i the piston directly opposes the downward pressure of the spring valve casing, since the high pressure acting` upon the valve piston surfaces is balanced byl vacting upwardly and 'ownwardly an the predetermined constant A from that actingon piston 12,

i 16 to theY pipe 23, reservoir Asimilar in construct-ion to the reservoir equal opposed areas at the top and bottom of the piston groove.

The loW pressure reservoir 28, which is -2-3., has a liquid therein which seals the lower end of the pipe entering the reservoir 2S from the reducing valve 2i. The upper end of reservoir 28 constitutes a chamber 31. The outlet pipe near the lower end of the reservoir 28 connects with a needle valve 29. The valve 29 has a restricted orifice 31 which is under control of a hand operated needle 30, discharging therefrom to any suitable source, such as the. supply tanli from which the pipe 19 is fed.

It will be observed that the reducin r valve 24;, reservoir 23, and restricted oriiice 31, constitute a means independent of4 the regulating device 8, for discharging pumped fluid at a predetermined constant rate, that is, the independence refers to the condition Where the pressure in reservoir 2S` diiers or, the changing pressure acting on piston 12 is cut ol' from the final delivery by the introduction of an independent or additional element. IThe iuid pressure variations due to load changes on the prime mover of the pump .and re ulating device 8, and the rate of iiovv o fluid past the drawoif point is equalized.

During the operation of the device, the prime mover 1 causes the shaft 11i to rotate carrying with it the eccentric 15 and operating the compressor 16 through the eccentric strap 18. Fluid, preferably a liquid such as oil, is draw into the pump 16 through the pipe 19 and is discharged from the pump v Y 22, chamber 13, and reducing valve 24. l/Vith the revolution of the shaft 14 constant, the quantity of oil pumped and its pressure will be constant andthe piston 12 of the regulating device 8 will therefore be held in practically constant position thereby maintaining a constant opening of the throttle valve 3. 1f tor any reason the speed of the shaft 14 is changed, say increased, the pressure in the pipe 23, reservoir '22, and chamber 13 increases because a greater quantity of oiL is pumped and raises the piston 12 and piston rod 10. This raising of the piston 12 causes a correspending lowering or closin of the throttle valve 3 and hence a resulting decrease to slightly below normal in the speed of the prime mover 1. As the speed of the prime mover decreases, the pressure in the high pressure reservoir 22 and chamber 13 will immediately drop and the throttle valve 3 will be opened restoring the speed to normal.

Suppose the constant pressure on the low ressure side of the valve 24.- to be 20 pounds absolute and the pressure in the high pressure reservoir 22 to vary from 40 to 80 pounds, with the spring 25 set to exert a pressure of 2O pounds per square section ot' the valve piston has a position permitting ilow at same rate as past needle valve 2t); then as liquid under increased pressure passes the piston 26, the pressure on the lo\v pressure side ot' the system will, momentarilybe raised a. slight amount above the '2O pounds normally maintained, and overcoming the downward pressure of the spring '25 will immediately close oill more passage by the piston 26 by forcing the piston up into the bore of the valve casing. With the needle valve 2S) open a certain amount, a constant flow of liuid will be maintained from the constant low pressure reservoir 28, a constant amount ot iluid will iow past the plunger 2G to replace the iluid discharged through the needle valve 29, because as the pressure momentarily increases the piston :in cuts oil` the tlow a proportionate amount.

Suppose it is desired to increase the speed of the prime mover a predetermined number of revolutions per minute. '.llieoiiice 31 of valve 29 is enlarged thus increasing the low from the low pressure reservoir 2S correspondingly. T he pressure on the low pressure side of' the system will then drop an amount proportional to the opening ot the orifice 31, causing the spring 25 to open the reducing valve 21. `This will cause the pressure in tho high pressure reservoir 22, pipe 23, and chamber 13 to decrease, resulting in a proportional increase ot thc speed of the prime mover 1 through the appropriate action ot regulating device 8, lever '7, and throttle valve 3.

The predetermined speed for any set osition of the needle valve 29, however, wi l be constant, as above explained, an increase or decrease in speed of the shaft 14: from the predetermined speed resulting automatically in a corresponding increase or decrease in the pressure in the high pressure end of the device, whieh in turn acts directly to decrease or increase the speed of the prime mover to the predetermined value. It Will be noted that. a. secondary regulation of the speed of the prime mover may be had by adjusting the hand wheel 2T. This adjustment, however, primarily ailects the sensitiveness of the device. It will he less sensitive it the initial compression of the spring 25 is increased or it' a heavier spring is used.

It should be understood that it is not desired to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

1t is claimedV and desired to secure by Letters Patent,-

1. In a speed regulating device, a prime mover,.a throttle valve for said prime mover, a pump driven by said prime mover, a high pressure system connected with the disinch on the cross 2G when the valve filiy f' maintain constant charge of said pump, means actuated bythe pressure in said Asystem for controlling said throttle, valve, a low pressure system, a reducing valve interposed between said high and low pressuresystems, and -means for drainage from said low pressure system at a predetermined constant rate.

2. Ina speed regulating device, aprirne eontrollingthe admissionmovver, means for of working fluid to said prime mover, a pump driven by said prime mover and discharging to a high pressure system, means actuatedhy the pressure in said high pres- Sure system for operating said controlling means, YV'a low pressure system, a reducing vlvie interposed between said high and low pressure systems, and means for drainage from said low pressure system at a predetermined constant rate.

3. In a speed regulating'device, a prime mover, means for controlling the admission of working fluid to said prime mover, a pump driven by said prime mover, a high pressure system receiving the discharge from said pump, means actuated by the pressure in said high pressure system to operate said controlling means, a low pressure'system, a reducing valve interposed between said high and low pressure systems, and manuallyndjustable means for drainage from said 10W pressure system at a predetermined constant rate.

' 4. In a speed regulating device, a rotary element the speed whereof .it is desired to maintain constant, means for restoring the speed of thev element from any value deviating from said desired constant speed, fluid pressure actuated means controlling said speed restoring means, a pump driven by said rotary element for pumping saidfluid, and means independent of said fluid pressure actuated means, for discharging said pumped fluid at a predetermined constant rate whereby the fluid pressure at the discharge differs from that actingy on said fluid pressure actuated means.

5. In a speedy regulating device,

a prime 'mover the speed whereof it is desired to when subjected to dierent. loads, means for restoring the -speed of said prime mover from any'value deviating lfrom .said desired constant speed, fluid pres- 'maintain constant when subjected to :f

means subjected to fiuic sure actuated means contre ing means, a pump driven mover for generating said' discharge means providing' an charging pumped fluid, actuated means being if said pump and said discA means preventing said fluid having direct access to'tlie char ed past said orilicch 6. du a speed regulatinaF device., l 7' mover'the speed wher-ect it des ent loads, means for restoring the said prime mover from any value d from said constant speed, a np driven le, said prime mover, means subjected to duid pressure generated by said pump for een- -trolling said speed restorinfr means, and means for confining to the neighborhood of the pump, Huid pressure variations due to load changes on said prime mover and' for equalizing the rate of flow of tluid at the draw-ofi point:

7. In a speed regulating device, a. prime mover, a throttle valve controlling the ad-y mission of the workin agent to said prime mover, a pump drivenh said prime mover, pressure generated by said pump for controlling Asaid throttle valve, and means including a pressure reducing valve for discharging said pumped fluid ata predetermined constant rate.

8. In a speed regulating mover, a throttle 'valve controlling the admission of the working agent to said prima mover, a pump driven enerated. by said pump for controlling sai throttle valve, and means including a pressure reducn iugvalve for discharging said pumped fluid at a predetermined con tant rate, and said fluid pressure subjected means on the high pressure side ci said reducing valve. ,c 'A

In testimony whereof, l. all'iii my signature in the presence 'of tv/o witnesses..

CARL Gf, SPRAD,

.Witnesscsz i Crus. L. Banen, W. H. LIEBER.

by said prime mover, means subjected to fluid pressure being located