US1041513A - Governing mechanism for turbines. - Google Patents

Description

R. H.. RICE. GOVERNING MBCHANSM FOR TURBINES.

APPLIGATIUN FILED JUNE 2, 1911.

Patented Oct. 15, 1912.

3 SHEETS-SHEET 1.

inver-5h01? R. H. RICE. l GOVERNING MBGHANISM FOR TURBINBS. APPLICATION FILED .TUNE 2, 1911.

lLlS., Patented @m1519112 s sHEBTs-sHEET 2.v

I mi@ schar- R. H. RICE. GOVBRNING MECHANISM FOR TURBINBS. APPLICATION FILED JUNE 2, 1911.

B SHBETS-SHEBT 3.

Fig/5.

` f Inventor; Richer-d H, me@

ail

RICHARD E. RICE, OF SWAMPSCOTT, MASSACHUSETTS, SSIGNOR T0 GENERAL ELECTRIC COMPANY, A CORPORATION 0F NEW YORV'K.

' GOVERNING MIECHANISM FOR TURB-INES.

Specification of Letters Patent.

Patented Oct. 15,1912.

`Application led''une 2, 1911. Serial No. 630,823.

'To all 'whom t may concern:

` Be it lnown that I, RICHARD H. RICE, a citizen of the United States, residing at Swampscott, county of Essex, State lof Massachusetts, have invented certain new and useful Improvements in Governing Mechanism for Turbines, of which the following is a specification.

The present inventionfrelates to governing mechanism for elastic fluid turbines and has for its object to provide a simple, reliable governing mechanism of improved construction for varying the amount of steam admitted to a turbine in accordance with the variations in load thereon.

For a consideration ot' what I believe to be novel and my inventicm'attention is directed to the accompanying description and the claims appended thereto.

In the accompanying drawings which illustrate one of the embodiments of my invention, Figure 1 is an end view of a turbine fitted with my improved governing mechanism, the latter being shown in vertical section; Fig. 2 is a sectional view showing a float whose position is responsive to the amount of fluid discharged by'a pump that in turn is driven by the turbine shaft, and Fig. 3 is a detail plan view of the pump and the float. n

5 indicates a steam turbine of any suitable construction. In the present instance it illustrates a turbine of the well known Curtis type.

6 indicates the turbine .shaft that is driven by the bucket wheel or rotor. Mounted on 'the shaft and driven thereby is a worm 7 that' in turn meshes with a worm Wheel 8 mounted on one end of an upright shaft 9. rIbis shaft is provided with suitable lbearings 10 and 11 thatl are carried by a tubular support 12. Situated one above and another below the worm wheel are thrust collars 13. On the lower end of the upright shaft is a spur gear 14 which meshes with the spur gear 15 carried by an auxiliaryshaft 16. The gears 14 and 15 form a gear pump of which 17 is the suction chamber and 18 the discharge chamber. The gears are located between an upper plate 19 and a lower plate 20, whichv plates are united by bolts 21 that pass through the horizontal casting 22 forming the casing of the pump. The casting is cored out to form a continuation of the suction chamber 17. Supported `by the right-hand end ofthe casting and feeding oil to the chamber is a wire screen or strainer 24. that serves to prevent foreign matter from passing with the oil into the lpump. The left-hand end of the casting 22 is also cored out to form a chamber and has an orifice in its upper wall in which is seated Yanozzle 25 having a central bore. This bore may be made cylindrical with longitudinal diverging passages 26 or the bore as a whole may be conical in shape with the section of greatest area at the top. Seated within said bore is a float 27 that makes a loose fit therein. The upper end of the float is [langed outwardly so that the oil liowing through the bore of the nozzle 25 will act on the bottom of the-float and also on said hanged portion, thereby increasing the eilective lifting power` of the oil for a given pressure. A further` advantage of this construction resides in the fact that oil cannot shoot out fro? i the nozzle and follow the rod connected with the float Where it passes throughl the cover of the reservoir. The pump and its associated parts are located within an oil containing reservoir 28, the latter being supported by the turbine base and provided with a removable top portion 29 that carries the tubular support 12. The reservoir hasV a removable cover 30. rThe cover is provided with a hand hole and a small cover 31 therefor by means of which access can be had to the strainer 24. Situated above the upright shaft 9 is a cover S2 that carries the upper thrust bearing 13. By removing this cover access may be had to the worm andwormv wheel.

The admission of steam to the turbine is controlled by a throttle valve 33 located in the casing 3l which in turn is supported by the casing of the turbine. The valve is provided with a stem 35 the lower end of which is seated in a forli' formed in thc right-hand end of the governor lever 36, the latter being pivotally'secured toabracliet 37 depending from the valve casing or the turbine, as is most convenient. On the lever is an adjustable counterweight 38 which may be moved toward and away from the pivot of the lever to adjust the effective action of the governing mechanism. To the governor lever is pivotally attached a rod 39, the lower end of which is provided with a knife edge that rests in the seat 40, the latter being located within a recess in the float 27. Both the knife edge and the seat are hardened to reduce wear.

In order to facilitate the assembly and removal of the governing mechanismfrom the turbine proper, the arran ement shown in Fig. 2 is provided, wherein 42 indicates a flanged neck or support that-is secured to the turbine casing or to some other suitable support. To the flange of the neck is bolted the top portion 29 of the reservoir containing an' orifice through which the shaft 44 extends. This shaft is provided with a sleeve keyed thereto. Surrounding the sleeve is a labyrinth packing ring 46. Mounted on the sleeve and adjacent to the packing is an oil thrower 47 to prevent the escape of oil throu h the packing. This throWer is provided with radially extending vanes 48 that serve to prevent oil from passing through the clearance. 6 indicates the turbine shaft having on its end a screw-threaded portion 49 of reduced cross-section and also a groove 50. Surrounding the'shaft is a sleeve 51 that is held in place on the shaft by a set screw 52. The worm 7 is provided with a hub-like extension that is snugly fitted over the sleeve 51, the set-screw 52 serving to pre- Vent the worm from moving axially on the turbine shaft and also to prevent the shaft from turning independently of the worm. The hub of the Worm is provided with an oil thrower 53 to prevent oil from working through the orifice in the annular flanged neck 42.

lt is to be noted that the lower part of the reservoir 28 is supported by the turbine base and that the upper part 29 of the reservoir, or more strictly the cover there for, is bolted to the flanged neck 42 as shown best in F ig.

2. Depending from said part 29 is the tubular support 12 of the upright shaft 9. To the lower end of the support is attached the cross piece containing the pump chambers and carrying the strainer and the discharge nozzle. By reason of this construct-ion after i the rod 39 is detached from the governor lever the portion 29, support 12, cross piece 22 etc. can all be removed as a unit by taking out the bolts 54 in the flanged neck. Obviously such a mechanism can be easily and quickly assembled.

The action of my improved governing mechanlsm 1s as tollowsz-,Steam 1s admitted to the valve chest by the'conduit shown under side of the float 27 and raises it by an in dotted lines, and passes through the valve to the nozzles or other fluid discharging devices of the turbine. As the rotor revolves due to the action of the steam on its buckets it causes the turbine shaft and worm 7 thereon to revolve. Motion is thereby transmitted to the worm wheel 8 and the shaft 9, the latter revolving at a speed which is proportional to the speed of the turbine shaft.

The pump at the lower end of the upright shaft 9'rece'ives oil from its suction chamber and after imparting pressure thereto delivers it to the discharge or pressurechamber The fluid in said chamber acts on the amount depending upon said pressure. The float is raised by the body'of oil underneath it until a balance is effected between the pressure of the oil actingthereon and the weight of ther governor .lever 36, counterweight 38 and associated parts. To 'state the matter in another way, there is a force tending to lift the float 27 which is opposed by another force and when these two forces are equal and opposite the float will remain sta-` `tionary. Since the throttle valve '33 is attached to the governor lever 36 it follows` Sio-f that the valve will take a position which is determined by the positions of the float and v. the governor lever and its counterweight. Assuming now that the turbine increases in speed due 'to the decrease in load or other v9,5 cause the pressure in the discharge chamber '31 :i of the pump increases and in so doing raises the float by a certain predetermined amount which causes the valve 33 to close by such an amountas will decrease the supply 'of steam 100 to the turbine, thereby reducing lts speeduntil the speed of the turbine has been restored to the normal. This action will slightly de` crease the pressure in the discharge chamber of the pump and the float 27 will take a posi- 105 tion corresponding to said pressure. On the other hand, if the speed of the turbine decreases the volume of oil discharged by the pump will be reduced by a corresponding amount, the float 27 will move downward 110 slightly due to the action of the counterweight 38 and the throttle valve 33 will increase its ope-ning and hence the steam supply by an amount suflicient to .restore the speed of the turbine shaft to normal operating conditions. It is lto be especially noted that the effective obstruction offered to the liquid by the float is decreased proportionately as the speed of the current of oil from the pump is increased thereby affording an increased outlet for the additional amount of oil delivered by the pump. This arrangement of parts is conducive to smooth, steady, operation and prevents choking which would. result in vibrations and unsatisfactory governing operation.

` I desire to have it understood that the speed varies with that of the of the nozzle,

manera accordance with the patent statutes, I have pleof operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but

apparatus shown is only illustrative, and that the invention can be carried out'by other means. "What I claim as new and desire to secure by Letters Patent of the United States, is-

l. In a governing mechanism for prime movers, the combination of a pump whose prime mover .for maintaining a continuous iiuid circulation, `a nozzle through which the pump discharges a column of fluid, the area of the nozzle increasingl in the direction of iow, a float arranged within the nozzle that rides on the fluid column` the position of the float varying with the volume of the discharge and thereby varying the effective low area a valve means controlling the admission of motive fluid to the prime mover, and a mechanical connection for transmitting the movements of the floatto the valve means.

provisions of the described the princr 2. In a governing mechanism for prime.

movers, the combination of a pump whose speed varies with t-hat ot the prime mover for maintaining a continuous fluid circulation, a nozzle through which the pump dis charges a column of fluid, the area of the nozzle increasing in the direction of How, a float arranged within the nozzle that rides on the tluid column, the position of the float varying with the 'rate of thereby increasing the eiiective flow area of the nozzle as the speed of. the pump increases and vice versa, a' valve controlling the admission of motive fluid to the prime i mover, a lever connected to the valve, and a connection for transmitting motion between the lever and float.

3'. In -a governing mechanism `for'primel movers,'the combinati-ion of a pump driven the prime mover to be governed, a chamber for the pump having a discharge orice, a float located in the orifice and arranged by its movements to increase and decrease the effective discharge area of the orifice, a valve actuated by the float for' controlling the and a means acting in opposition to the float. 2 i 4. In a governing mechanism of thecharacter described, the combination of a pump, a lloat comprising. a body portion and an outwardly extending flange, saidl hodyfpor- .tion and flange both path ot` and acted upon by 'the discharge of the pump,

control the passage of motive fluid, andan discharge and admission of fluid to the prime mover,

being located inthe a valve moved by the float to' adjustable means acting in opposition to the ifioat. y

In a mechanism of the character described, the combination of a pump, a discharge chamber therefor, a nozzle through which the chamber discharges, the crosssectional area of said nozzle being greater at one end than the other, a float located in the nozzle and moving in a direction to increase the discharge area as the volume of `fluid discharged by the pump increases, and a valve means actuated by the oat.

n. In a mechanism ofthe character described, the combination of a pump, a discharge chamber therefor, a nozzle for the chamber that diverges outwardly and through which liuid from the pump Hows, a ioat located in the nozzle and having an outwardly flaring flange, a throttle valve, a lever connected thereto, a means connecting the float and lever, and a counterbalanee acting through the lever to oppose certainv movements of the float.

7. In combination, a prime mover, a pump, a shaftdriven bythe prime mover for actuating the pump, a support for the pump shaft that is carried by the prime mover, a casing for the pump carried by said support and having a discharge cham- `ber, a iioat acted upon by the Huid leaving the discharge chamber, a reservoir in which the pump is suspended, and a valve actuated by the float.

8. In combination, a prime mover, a main shaft therefor, a pump, a pump shaft, gearing between the two shafts, a support for the pump shaft, a casing `)carried by the lower end of thesupport and provided with supply and discharge chambers, a discharge nozzle, a oat in the nozzle, a reservoir in ywhich the pump is submerged, a Vvalve actuated by the float, and ,a means also acting on the valve in opposition to the iioat.

9. In a governing mechanism for prime movers, the combination of a-pump driven by the prime mover-and' at a speed varying therewith, a chamber for the pump having a discharge member, a device that extends into the memberand obstructs the How of Huid therethrough to a certain extent only, said device moving outwardly from said member as the liow'from the pump increases to decrease the 'obstruction to the flow through the member said flow decreases to increase said obstructiomand a regulator for the lprime mover, which is: controlled in`- its action by the movements of the device.

l0. In a governing mechanism for prime movers, the combination of a pump driven by the prime mover and varying in speed therewith,a lioat' having an outwardly extending liange on its upper end, a means for directing and moving into it'asthe Huid dischaiged by the pump against the under-side ofthe fioat and its flange and raising it by an amountdependent upon the speed mover Whose action is responsive to movements of the oat and means. lo In Wltness whereof, I have hereunto set ofthe. pump; the Weight of the float acting my hand this thirty-first day of May, 1911.

to oppose the lftingeffect of the Huid, a means acting on the float in opposition to the fluid, and a means for controlhng. the

admission of motive fluid to the prime 4 RICHARD H. RICE. Witnesses:

JOHN A. MCMANUS, Jr., CHARLES A. BARNARD.

Images