US1629318A - Regulating means for elastic-fluid turbines - Google Patents

Description

1,629,318 y 17 R. G. sTANngRwlcK REGULATING MEANS FOR ELASTIC FLUID TURBINBS Filed Nov. 2a, 1925 VALI/E MEAM F01? TURBINE 3 I o v 5 6 V A\ 3/ '39 B 1 a7 0" J Fig.2.

Inventor. Reginald G. Stomderwick,

Patented May 17, 1927.

UNITED STATES PATENT OFFICE.

GENERAL ELECTRIC COMPANY,

A CORPORATION or NEW YORK.

REGULATING MEANS FOR ELASTIC-FLUID TURBINES.

Application filed Itfovember 2a, 1925. Serial No. 72,055.

The present invention relates to regulating means or governors for elastic-fluid turbines or other prime movers.

It is known that an isochronous governor cannot be made to operate in the true sense of the word on account of certain fundamental conditions met with in actual practice. However, what appears to be an isochronous governor can be madeup by providing, in connection with a governor of appreciable width of regulation a correction device which comes into action to correct the governor for changes due to its inherent width of regulation.

The object of my invention is to provide an improved governor having a correction device whereby for practical purposes thegovernor is rendered isochronous, and for .a consideration of what I believe to be novel and my invention, attention is directed to the following specification and the claims appended thereto.

In the drawing, Fig. 1 is a diagrammaticview of a regulating means embodyin my invention, and Fig. 2 is a detail sectlonal view taken on line 2-2,'Fig. 1.

Referring to the drawing, 5 indicates the admission end of an elastic-fluid turbine to which elasticfluid is supplied by a suitable valve means 6 which is opened and closed by turning movements of a cam shaft 7. The valve meansand cam arrangement for operating it may be of the same general type as that shown in the patent to Mr. E. D. Dickinson and myself, No. 1,560,416 granted November 3, 1925 The turbine shaft is indicated at 8 and the oil tank is indicated at.9. The illustration of the turbine in Fig. 1 is wholly diagrammatic. Theturbine casing 5 and. the shaft 8 are not shown in correct relation to each other but the turbine casing is brought around into the plane of the paper in order to illustrate more clearly the arrangement 1 of the governor mechanism and its connection to the'turbine valve gear. On the end of cam shaft 7 is a pinion 10 which meshes with a rack 11 formed on the upper end of a rod 12. The lower end of rod 12 is connected to a piston 13. which slides in a suitable cylinder 14.

'- Arranged between the upper side of piston 13 and a spring plate 15 is a spring 16 which biases piston 13 toward the lower end of cylinder 14 andthe. valve means 6 toward closed position. With the piston in the meshes with a worm wheel 18 mounted on 4 a vertical shaft 19. Shaft 19 is mounted in suitable bearings, oneof'which is indicated at 2.0, and at its lower end it is connected to drive an oil pump 21 located in tank 9. Oil pump 21 takes o1l.from tank 9 through a suitable intake strainer 22 and delivers oil through conduit 23 to a pipe 24. Connected to a pipe 24 is a pressure relief valve 25 which discharges back to tank 9 and whichis set to maintain in pipe 24a certain desired pressure.

Pipe 24 delivers oil through a non-turn valve 26 and an orifice 27 in a plate 27 to a pressure 'pipe 28 and a by-pass-pipe 29 which branches therefrom] Since there is essentially constant pressure in pipe 24, oil will be delivered through orifice 27 to pipes '28 and 29 always at a definite rate, depending upon the pressure existing in such pipes.- Pipe'28 is connected to cylinder 14 beneath piston 13 and conveys pressure to the underside of the piston for efiecting operation of the valve means 6. By-passpipe 29 is 'connected to a pilot valve structure A compriss. ing an annular chamber '30 in the inner wall of a pilot valve casing 31. In casing 31 is a bushing or sleeve 32 provided with oles 33 located in alignment with; chamber 30. Bushing 32 extends throughout the length of casing 31 andis connected at its upper end to alever 34 which is. fulcrumed on the upper end of an arm.35 which in turn is pivotally supported on a flange at the base of pilot valve casin' 31. Inside bushing or sleeve 32 is a pi l ot valve 36 which is in the form of a tube or sleeve and is connected at its lower end to the weight arms 37 of a centrifu 1 speed governor B so as to turn therewith This speed governor is the primary governor for the turbine. For

the purpose of this diagrammatic il1ustration, I have shown weight arms 37 pivotally connected directly to the lower end of pilot valve 36. This direct connection or any other suitable connecting arrangement may be used.- In actual practice, I prefer to use.

i the specific arrangement disclosed in the ap- ,valve is lowered inbushing 32 to uncover chamber and when the speed decreases the pilot valve is raised in bushing 32 to cover chamber 30.

The lever 34 is connected by a link 38 to a lever 39 which at its left-hand end is pivotally connected to rod 12. The other end of lever 39 is pivo'tally connected to the upper end of a stem 40, which forms a part of a speed correcting device C. Stem 40 projects downward into a cylinder 41 and is there connected to a'piston 42 which slides in c linder 41. Piston 42 is biased toward the ottom of cylinder 41 by a spring 42.

Adjacent cylinder 41 is a jbya pilot valve casing 43 connected to cylinder 41 beneath piston 42 assage 44. Passage 1 interior of pilot valve casing 43 by a narrow discharge point.

in line with link elongated slot 45. Connected to pilot valve casing 43 is a supply conduit 46 and a dis charge conduit 47. Conduit 46 maybe connected to any suitable supply of fluid pres sure and conduit 47 may lead to any suitable In pilot valve casing 43 is a stem 48 upon which is "mounted a valve 49 which is of a length such that it normally covers completely elongated slot 45. Also stem 48 has an enlargement 50 which fits pilot valve casing '43 to prevent leakage of oil in an upward direction. The upper end of stem48 is connected to lever 39' directly 38, the point of :connection being indicated at 51. v

With the above-described arrangement, when the turbine is running, pump 21 supplies oil through pipe 24 and orifice 27 to pressure pipe 28 and by-pass pipe 29. The pressure of the oil in pipe 24 is fixed at a definite value b pressure relief valve 25 so that oil is supp ied to pipes 28 and 29 at a definite pressure. Oil escapes continuously from pipe 29 throughports .33 to the interior of'pilot valve casing 31 from whence it runs down tank 9. The pressure in pipe 28 and hence that to which piston, 13 is subjected deends directly upon therate atwhich oil is y passed through conduit 29 and this in.

turn depends directly-upon the extent to which] ports 33 are uncovered. The extent to'which ports 33 are uncovered. depends 44 connects to the through tubular pilot valve 36. to

upon the relative positions of pilot valve 36 and pilot valve bushing 32. Pilot valve 49 normally exactly covers elongated slot 45 and piston 42 is held in sition by the oil entra ped beneath it.

Assume now that, ue to an increase in load, the speed of 'the turbine decreases.

a certain definite po- 7 admitting additional elastic fluid to the f turbine in an effort to restore it to its former speed. \Vhen piston 13 moves upward it carries with it the left-hand end of lever 39. Lever 39 fulcrums on the upper end of stem 40 and through link 38 and lever 34 raises the pilot valve bushing 32,. thereby moving ports 33 upward relatively-to the end of pilot valve 36. This uncovers ports 33 somewhat, permitting oil to escape'more rapidly through them which has the effect of lowering the pressure in pressure pipe 28, tending. thereby to restore pilot valve 36 and bushing 32 to their former relative positions. In this respect the \mechanism operates after the manner of a follow-up device/ If the ports were to remain in this position, however, the speed would settle to a point somewhat less than before due to the inherent width of regulation of the governor. However, when lever 39 moves with rod 12, it raises pilot valve 49 in pilot valve casing 43 with the result that the lower end of slot 45 is uncovered, permitting fluid pressure to escape from cylinder 41 beneath piston 42. Spring 42 thereupon forces piston 42 downward, lever 39 pivoting on its connection with .rod 12. This serves to lower pilot valve bushing 32, the movement taking place until pilot valve 49 again completely covers slot 45. This movement of pilot valve bushing 32 closes ofl' further ports 33 with the result that the pressure in pipe 28 is. increased slightly to open somewhat further the valve means 6, thereby admitting'additional elastic fluid to theturbine to increase its speed. The parts are so proportioned and arranged that this movement is just sufficient to bring the speed of the turbine back lit] to its former value. ,As a result. therefore, I

the speed of the turbine is the same as it was before the change occurred. I

'If the speed of the turbine is increased due to a'decrease in load, then an action. similar to that already described. except that it takes place in the opposite direction, oc-

curs, the speed again finally settling,.at the new load, at that which it was originally.

at a rate slower than the rate of motion of In other Words, thethe primary governor. correct ng device must always lag behind the primary governor. This my improved correcting device does, and always by a defi- .nite amount irrespective of the rate of change of the primary governor, it being well recognized that the rate of motion of a primary governor varies directly with the rate in change of load. Considering my improved construction, it will be seen that upon change in load the primary governor first responds to effect an adjustment of the valve mechanism controlling the flow .of.

' previous movement of, the

, the prime mover,

elastic fluid to the turbine. The movement of the-valve mechanism in response to the primary speed overnor then moves the speed correcting evice to cause it to come into action and effect a correcting movement of the pilot valve structure A. However, this act-ion .does not take place until piston 42 moves in cylinder 41 and, owing to the comparatively narrow width of slot 45, the movement of piston 42 is retarded or delayed for a certain amount of time after pilot valve 49 moves. As a result, the correcting action takes place a short interval of time after the speed governor has acted. By choosing a suitable width for slot 45, this interval of time may be given the desired value.

Pilot'va e 49 exactly covers slot 45 so that upon the least movement of lever 39, slot 45 will be uncovered to effect a correcting action. As a result, the correcting de vice will operateto maintain the speed constant. In other words,'-it will function to- 'render the governor isochronous for all practical purposes, and this without afl'ecting adversely the stability of the governing.

Vhat I claim as new and desire to secure by Letters Patent of the-United States, is,

1. Ina governing mechanism for prime movers, the combination of valve means controlling the admission of elastic fluid to a fluid-actuated motor, including a pilot valve structure for effecting movement of the Valve means, a primary governor for actuating the pilot valve structure, a follow-up mechanism for restoring the pilot valve structure, correcting means to correct for the inherent width of regulation of the primary governor comprising a motor connected to the pilot valve structure, and means actuated by the follow-up mechanism for controlling said motor.

' and a restoring bushing mary 2. In a governing mechanism for prime movers, the combination of valve means controlling the admission of elastic fluid to the prime mover, a fluid-actuated motor including a pilot valve structure for effecting mcnieg ment of the valve means, a primary governor for actuating the pilot valve structure,

a follow-up mechan sin for restoring the pilot valve structure, and correcting means to correct for the inherent Width. of regulation of the fluid-actuated motor, a pilot valve controlling the admission connecting the pilot valve to a of the governing mechanism.

3. In a governing mechanism for, prime movers, the combination of valve means con trolling the admission of elastic fluid to the moving part prime mover, a fluid-actuated motor including a pilot valve structure for effecting movement of the valve means, a primary governor for actuating thepilot valve struc-; ture, a follow-up mechanism for restoring the pilot valve structure, and correcting means to correct for theinherent width of regulation of the primary governor comprising a fluid-actuated motor, a pilot valve controlling the admission of fluid to it, the passage means through which fluid flows to the fluid-actuated motor being of'rest'ricted primary governor comprising a of fluid to it, and means 1 area so as to retard the flow, and means connecting the pilot valve to a moving part of the governing mechanism.

4. The combination with valve means 'for controlling the admission of elastic fluid to a prime mover, of a fluid-actuated member, means connectin itto said valve-means, a structure comprising a pilot valve sleeve for controlling the admission of fluid to said member, a prigovernor connected to the pilot valve sleeve, means connecting the restoring bushing to said. connecting means, and a speed correcting device comprising a fluid-actuated,

member connected to said restoring bushing" and a pilot'valve connected to said connecting means. Y

5. The combination with .valve means for controlling the admission of elastic fluid to a prime mover, of afluid-actuated member,v

means connecting it to said valve means, a structure comprising a pilot valve sleeve and a restoring bushing for controlling the admission'of fluid to said member, a primary governor connected to the pilot valve sleeve, means including a lever connecting the restoring bushing to said connecting means, a fluid-actuated member which forms a fulcrum for said lever, and a pilot valve which is connected to said lever and controls the admission of elastic fluid to said secondnamed fluid-actuated member.

6. In a governing mechanism for prime movers, the combination of valve means controlling the admission of elastiefluid to the 20 Y valve structure to correct for inherentwidth to the piston, a prlmary prime mover, a fluid-actuated motor includmg a pilot valve structure for effecting movement of the valve means, a primaryv governor for actuating the pilot valve struc ture, a follow-up mechanism for restoring the pilot valve structure, correcting means to correct for the inherent width of regulationof the primary governor comprising a motor connected to the pilot valve structure, and means actuated by a moving part of the governing mechanism for controlling said motor.

7. The combination with a governing mechanism comprising a valve means, a fluid-actuated piston for moving it, a pilot valve structure controlling the fluid supplied governor connected to the pilot valve structure, and a follow-up connection for the pilot valve structure, of means for effecting vmovement of the pilot of regulation of the primary governor, said means comprising a fluid-actuated piston connected to the pilot valve structure, and a ,pilot valve controlling the fluid supplied thereto, said pilot valve being moved by a moving part of the governing mechanism.

8. The combination With a governing mechanism comprising a valve means, a

fluid-actuated piston for moving it, a pilot valve structure controlling the fluid supplied valve structure to correct for inherent width of regulation of the primary governor, said means comprising a fluid-actuated piston connected to the pilot valve structure,a pilot valve controlling the fluid supplied thereto,

said pilot valve beingmoved by the follow.

up connection. In witness whereof, I have hereunto set my hand this 24th day of November, 1925.

REGINALD G. STANDERW'ICK.

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