US751888A - Governing mechanism for turbines - Google Patents

Description

4. 0 9 l 91 Rm. E UI D E N E E mi N A .1 Pv B R U T w MF .S Nm TlTI- um I .H WC .E TluM G N .I N R E V, O G om 8 8 L. 5 7 0. N

APPLICATION FILED APR. 7, 1903. A

4 SHEETS-SHEET 2.

H0 MODEL.

www; WW

No. 751,888. PATENTED FEB. 9, 1,904.

J. WXLKINSON.

GOVERNING' MBCHANISM FOB. TURBINBS- APPLIOATIGN FILED APB.. 7, 1903.

4 sHEETssHEET 4.

N0 MODEL.

UNITED STATE-sy Patented February 9, 1904.

PATENT OEEICE.

JAMES WILKINSON, vOF BIRIVIINGHAM, ALABAMA, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO THE WILKINSON STEAM TURBINE COM- PANY, A CORPORATION OF ALABAMA;A

GOVERNING NIECHANISM FOR TURBINES.

SPECIFICATION forming part of Letters Patent No. 751,888, dated February 9, 1904.

Application filed April 7, 1903.

To a/ZZ whom it may concern):

Be it known that I, JAMES WILKINSON, a citizen of the United States, residing at Birmingham, in the Ycounty of Jefferson and State of Alabama, have invented certain new and useful Improvements in Governing Mechanism lation of turbines by oscillating one or more 4 of the valves controlling the admission of pressure to the nozzles, so that it was delivered to the rotor in pulsations or blasts which varied in duration according to the 2 5 load.

It is the object of my present invention to incorporate this oscillatory regulation into an improved governing mechanism especially adapted to control high-power turbines employing large numbers of nozzles and operating under loads that may. vary materially.

In carrying out my invention I use a speedgovernor-controlled collar or commutator provided with separate circular contac'f-platesy and interposed bands of insulation, which is engaged by brushes connected to wires controlling the valve-motors eitherv singly `or in groups.

It is a further object of my invention to 40 provide an improved semirotary valve located in the throat of each nozzle and forming when in its open position a part or the whole thereof and to perfect the electromagnetic operating means for the valves. I alsow contemplate using a complete circular row of nozzles around the turbine to obtain the full power of the rotor-wheel and have adapted the gov- Y ernor to control them separately or in oppo- Seria-l No. 151,504. .(No model.)

sitely-disposed groups of any desired number of nozzles.

In the accompanying drawings, illustrating my invention and forming a part hereof, Figure lis a vertical sectional view of the turbine, showing the governing mechanism in elevation. Fig. lnl is a diagrammatic view of a generatory with its terminals suitably grounded. Fig. 2 shows the turbine in plan with the governor broken away and shown in elevation and the valve-motors coupled up in pairs. Fig. 3 is a detail view of a modified 60 form of the governor collar or commutator. Fig, 4 is an enlarged sectional view of the valve and its mounting in the turbine-shell shown in Fig. l with the motor shown in elevation. broken away along the line a' x of. said figure, showing the nozzles and rotor-vanes in section and the semrotary valves in open and closed positions. Fig. 6 is an end view of the valvearmature commutator through the line y y of Fig. 4, showing the electrical connections with an illustrative governor action, the valve being in its closed position. Fig. 7 is the same, as Fig. 6, showing the position of the parts when the valve is in its open position. Fig. S is a transverse section throughv .e e of Fig. 4, showing the construction of the motor-armature. Fig. 9 is a detail Qviewof the valve removed, showing in connection therewith'its motor-armature and commutator. Fig. 10 8O shows a modiiied or segmental valve. Fig.

l1 is a diagrammatic view illustrating the action of a valve throughout the range of travel of the governor-collar.

The same reference-numerals refer to simi- S 5 lar parts throughout the drawings.

The rotor or wheel l, with two rows of peripheral concave-convex vanes 2, is rigidly xed to the main shaft 3, which has suitable bearings in the turbine-frame, in which it is vertically mounted. The turbine-casing 4 has arranged around its upper periphery an annular chamber 5, provided with inletfports 6 for the admission of elastic Huid, which is delivered at an acute angle against the vanes 9 5 through a complete circular row of expansion Fig. 5 is a side view of Fig. 4, partly 65' front of the nozzle.

casing 4 and disposed between the rows ofv vanes 2 on the rotor serves to direct the passage of elastic fluid through said vanes to an annular chamber 8, from which it is exhausted through the ports 9 either to open air or to a condenser.

The general construction and operation of the turbine as just described is of the usual character, and may therefore be varied Without affecting my present invention, which relates to the governing and regulating mechanism.

IA provide each of the nozzles 7 with a rotary valve 10, cylindrical in cross-section and having an elongated flaring opening 11 disposed centrally and longitudinally thereof, through which the elastic Huid is admitted to the expansion-passages from the chamber 5. valve is located in the throat or reduced portion 12 of its respective nozzle between the frames 13 and provided with suitable bearings 14 and stuffing-boxes 15 at either end, as more clearly shown in Fig. 4. The valve-opening 11 iares upwardly or towardthe chamber 5, having its side walls conveXly curved, so that when in an open position they correspond with the curve of the nozzle-frames 13 and present an uninterrupted passage for the elastic Huid. By locating a valve of this construction in the reduced portion of the nozzle it forms a part or, if desired, the Whole of the throat when in its open position, thus providing a ready means for repairing or replacing the throat independently of the nozzle-frames. At the same time it avoids the friction and reduction of pressure resulting from the use of valves interposed in the steam-chamber and operating in In its open position the valve is balanced independently of the pressure, by reason of its forming a portion of the throat; but when closed it is no longer balanced, the excess of pressure above the valve serving the advantageous purpose of holding it securely against its seat. If desired, the valve may be segmental, so that it forms but one side of the throat when open; but in either construction, its motion being rotary and covering an angle less than forty-live degrees, little power will be required to operate it. The valvestem 16 extends outwardly from the casing and through a coupling 17 is detachably connected with the shaft of a valve-operating motor 18. These motors are supplied with electric potential by a generator Gr, whose positive mainleads to a special conductor, which may be a metallic ground P, while the negative main leads to an earth-ground N. The motor-armature 19 is keyed to the shaft 20, suitably mounted in bearings at each end of the motor-frame and connected through 17 to the valve-stem 16. The armature has `poles Each 21 and 22, whose outer surfaces are curved in the arc of a circle struck from the center of shaft 20, corresponding with which are the reversely-curved pole- pieces 23 and 24 of the field, suitably secured to the motor-casing. The armature-coils 25 are wound lengthwise between the poles and connected at one end to segments 26 and 27 and at the-other to segments 28 and 29 of the motor-commutator 30. A differentially-wound resistance-coil 31 is interposed among the armature-coils, connecting them at their middle with plate 32 of the commutator located between segments 27 and 29, from which it is suitably insulated. Segments of insulation 33 and 34 are interposed between segments 26 29 and 27 28. The fieldcoils 35 are connected to the conductor P and to a brush 36, which engages commutator 3() and is arranged to contact with segments 27, 32, and 29 in turn as the valve oscillates. A brush 37, which contacts with segment 26 when the valve is closed, is connected by wire 38 with a brush 39, engaging the governorcommutator 40. A brush 41 contacts with segment 28 when the valve is open and is connected by wire 42 with a brush 43, engaging commutator 40, which carries a spirally-tapered contact-plate 44, suitablyconnected with the generator through wire 45 to ground N.

Referring now to Fig. 6 and assuming the generator to have the proper difference of potential at its terminals, this difference will eX- ist in the apparatus as follows: The sleeve 44 will be charged from the N side and the brush 39 from the P side through the ield 35, brush 36, segment 29, coil 25, segment 26, brush 37 and wire 38, when the valve will be closed. If then during the rotation of the commutator 40 the brush 39 makes contact with plate 44, an electric current will be established in the coils 35 and 25, which will so magnetize the armature-poles with regard to the lield that the armature will be caused to rotate in the Valve-opening direction. The full strength of the current is used to start the rotation of the armature, and the torque is increased by reason of the curved structure of the field and armature poles, which permits a close and eX- tended inuence throughout the magnetic lield. Though the full current is used to start the rotation, it is my intention to reduce the arc of discharge when the current is broken and Save current by cutting out half of the armature-coils from the circuit and at the same time interposing a resistance 31 as soon as the armature movement is well under way. Thus as the commutator 30 rotates from its position in Fig. 6 to that of Fig. 7 the segment 29 passes from under brush 36, which then engages segment 32. This segment is connected to the middle of the armature-coils through the differentially-wound resistance 31, suicient to greatly reduce the current liowing through the coils 25 and 35, so that when the circuit is broken by the segment 26 passing from under the brush 37 IOO 'tion of the armature movement accomplished by its momentum assisted by the eccentric bearing 46 on the commutator 30, provided with two stop- shoulders 47 and 48, which engage a shoe 49, carried by a spring-arm 50,` 'bolted to the motor-frame, which shoe rides on said eccentric bearing and serves to limit the armatures movement either way and hold it in position between reversals.

Referring to Fig. 7, which shows the armature reversed and the valve open, brush 36 is in contact with segment 27, brush 41 with segment 28, wire 38 open-circuited, and wire 42 alive to the brush 43, so that upon the latters contact with plate 44 the coils 25 and'35 will be energized and their cores polarized in relaf tively reversed directions, so that the armature movement will thus be reversed and the valve closed. Current is entirely cut oi during the periods of the valves inactivity, and

since the resistance is interposed almost im-Y mediately after the armature-coils have been energized the motor will operate with a minimum amount of current. The motor-frames are secured to brackets 51, extending outwardly from the turbine, by bolts 52, which pass through elongated slots 53, which provide for a rocking adjustment. Y

I regulate the number of passive nozzles maintained open or closed and the oscillation of the active valves by a centrifugal governing device 54 and a governor-collar 40, which revolves with the shaft 3 and is shifted endwise upon it by the action of the governorweights through connecting-arms 55, as shown in Fig. 6, to which l am now referring. Upon the surface of this collar and suitably insulated therefrom is a contact-plate 44, disposed at a slight spiral, which ends abruptly at the shoulders 56 and 57, the latter of which has a lead of the former slightly in excess of the width of the brushes 39 and 43 to avoid the chance of short-circuiting through plate 44, so that, considering the collar to revolve according to the arrow, the brush 43 will have passed oii' the shoulder 56 onto the insulation with which the collar is surfaced above and below the plate before brush 39 will have contacted with shoulder 57. The valve-opening brushes 39, 39a, and 39b are equidistant, respectively, from the valveclosing brushes 43, 43a, and 43", each pair being spaced a distance slightly greater than the width of the plate 44, which is uniform throughout except between the shoulders. 56 and 57, to give a clearance which will prevent short-circuiting. Each of the brushes 43 is spaced from the other a distance corresponding with the elevation of the lspiral of the sleeve 44, so that only one of them at a time can intermittently engage said sleeve to eiiect an oscillai tory movement of thevalve or valves it controls, and the same is true of brushes 39. Now, assuming the governor and its collar or commutator 40 to be revolving, sensitive to the turbines speed, the brushes 39 and 43 will be alternately in contact with the sleeve 44 by virtue'of its spirally-tapered edges once during each complete revolution of the sleeve, and since when they contact with said sleeve they energize the motor-armature to open and close the valve itis obvious that the valves movements depend upon the length of time each brush remains in contact with the sleeve. This is therbasis of my oscillatory regulation, because as the load of the turbine diminishes its speed will increase and the sleeve will rise, thus maintaining contact for a greater portion of its revolution with the valve-closing brush 43, whereas when the load increases the sleeve will move in the opposite direction and maintain a longer contact with the valve-opening brush 39. By these means the valve or valves controlled by the brushes 39 and 43 will be Y oscillated sensitive to the turbine speed and will regulate the eiiciency of the turbine in direct proportion to the load by varying the duration of the blasts of elastic fluid which are admitted to the nozzles while the valveopening brush makes contact. Since the valve opens .fully each time the armature-coils are energized through brush 39, there will be no wiredrawing or throttling of the nozzles and the duid-pressure will always be admitted, so that its volume and the velocity into which it is largely converted inthe nozzles remain uniform. in the diagrammatic view Fig. 1l, illustrating the action of a valve under an increasing load, the line c represents the valve passively closed, while o represents it passively open. Intermediate these points the length of the vertical lines indicates the volume and velocity and their distance apart the beginning and ending of the pulsations. The points r r in the line above this gure denote the series of complete revolutions of the commutator 40, while the upper horizontal lines of increasing length denote the increasing portions of succeeding revolutions, during which the valve is maintained open until it becomes passively open, whereupon the oscillations of the valve next above commences. This method of regulating the motor-fluid supply to the turbine and the controller means for governing the operation of the supply-valves form the subjectmatter of pend ing applications and are not broadly claimed herein.

VIn adapting my governing mechanism to turbines of large powers in which a continuous row of nozzles are employed extending entirely around the turbine and having each a valve and a motor therefor, as shown in Figs. l and 2, the governor-commutator 40 is mounted on a horizontal shaft 58 and longituroo dinally movable thereon by the lever 58, pivotally mounted in a vertical extension 59 of the turbine-frame and connected to the slipcollar 60 on the vertically-movable governorcollar 6l and a similar slip-collar 62 on the commutator near the inner end thereof. The vertical movement of the collar 61 thus serves to shift the commutator on shaft 58, to which it is loosely keyed by feather 63, the shaft being rotated bythe main shaft 3 through the bevel- gears 64 and 65. Because of the' large number of valve-motors it is desirable to provide the commutator with two or more sleeves 44, which have similarly-shaped strips of insulation interposed between them, so that the brushes may be grouped in banks of twelve for each sleeve, as shown in Fig. l, when each corresponding pair of valve opening and closing brushes operates four of the forty-eight motors shown simultaneously. These motors are oppositely disposed, so that the action of their nozzles balance each other, and any desired number may thus be grouped together. In the case of Fig. 2 I have shown forty-two nozzles with the valve-operating motors therefor connected in pairs and controlled by three banks of brushes of fourteen each and three contact-sleeves 44 on the commutator. Each bank of brushes is distinct from the others and comprises siX valve-opening brushes 39 and six corresponding valve-closing brushes 43, over which the contact-sleeve 44 is moved by the governor to oscillate the valves controlled by each pair of brushes, while the rest are either open or closed, according to the load. With each bank of brushes, as also in Fig. 6, it is evident that one valve-opening brush and its corresponding Valve-closing brush will always be inintermittent engagement with the tapering edges of its contact-sleeve, while the rest of the brushes will be in constant contact with eitherl the sleeve or the adjoining strip of insulation, so that their valves are passively open or closed. If we take the commutator near the lowest point of its throw, as shown in Figs. l and 2, in dotted lines, Fig. 6, and for convenience describing the action of the bank of brushes in the latter gure as illustrative of the others, we find brushes 39 and 39a will be in constant engagement with the sleeve, thus maintaining their respective valves open, While brushes 39b and 43 (or 39e and 43e in Fig. l) will be on the taper edges of the sleeve, and therefore ,regulating the turbine by oscillating their valves. If the reduction of load be gradual, the commutator will move up slowly until the sleeve contacts with brushes 39a and 43, when the valve of brush 39b will be maintained closed. This same movement will continue until all the valves controlled by brushes 39 and 39b are closed and brush 39 is active. YAt the extremes of the collars travel, which occurs when the load is either full on or off, the plate 44 is so shifted that it engages all of the valve-opening brushes to hold their nozzles constantly open or all the valve-closing brushes to hold their nozzles constantly closed. If, on the other hand, there should be large and sudden variations in the load, the governor will sweep the sleeve back and forth over the bank of brushes so rapidly that the oscillatory regulation derived from the tapering edges of the sleeve is lost, and the nozzles are thrown open or closed to effect the regulation. Under such circumstances the commutator shown in Fig. 3 mav be used, and it is found that the slight pumping action of the turbine during a steady load will in a way compensate for the oscillatory control derived from the tapering sleeves by causing a slight oscillation of the commutator itself. In these figures the field-wires 35 are connected to a common wire 66 and through it to the ground I).

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. In a turbine, the combination of a number of nozzles, valves for said nozzles, rotary motors transmitting motion to said valves to actuate them, and a governor for controlling the operation of said motors to throw said valves into and out of service.

2. In an elastic-fluid turbine, a rotating element, a fluid-supply passage, a series of partitions therein which directthe fluid in streams against said rotating element, a rotary valve controlling the admission of fluid to each passage formed by said partitions, and a governor controlling the operation of said valves.

3. In an elastic-fluid turbine having a nozzle, a rotary valve having only open and closed positions .controlling the admission of fluidpressure to said nozzle, and governor-controlled means to operate said valve.

4; In an elastic-fluid turbine having one or more nozzles, a governor-controlled electrically-operated rotary valve for each nozzle controlling the admission of fluid-pressure thereto.

5. In an elastic-Huid turbine, a plurality of nozzles, a rotary valve for each nozzle located in the throat thereof, and electromagnetic means suitably governed for rotating each Valve.

6. In an elastic-uid turbine, an expansionpassage and a valve in the throat thereof that forms when open a symmetrically-curved intermediate part ofeach side of the contracted portion of said passage.

7. In an elastic-Huid turbine, a series of nozzles, governor-controlled rotary valves controlling the admission of fluid-pressure thereto and substantially radially disposed about said turbine.

8. In an elastic-fluid turbine, a circular series of nozzles, rotary valves controlling the admission of Huid-pressure thereto and having IOO IIO

IZO

. thereto and Which is balanced When open, and

means sensitive to the speed of the turbine for operating said valve.

10. In an elastic-fluid turbine, an expansionnozzle, a valve having only open and closed y positions which controls the admission of Huid-pressure thereto and when open is balanced and when closed is held iirmly to its seat by the unbalanced pressure, and means sensitive to the speed of the turbine for .0perating said valve.

11. In an elastic-fluid turbine, a governing or regulating mechanism for a pulsatory feed whereby impulses orblasts of uniform volume but varying in duration are admitted by a rotary valve, suitably controlled, to a nozzlepassage.

12. In an elastic-duid turbine, a nozzle, a governing or regulating mechanism for controlling the admission of iiuidpressure to said nozzle by oscillating a rotary valve having the periods of rest at each end of its travel governed sensitive to the turbines load.

1 13. In an elastic-Huid turbine a governing mechanism comprising electric magnetic means for controiling the admission of iiuidpressure to said turbine and governor-actuated tapered controller devices governing the action of said means.

14. In an elastic-Huid turbine, a rotating element, a series of nozzles, valves therefor, electromagnetic means controliing said valves, a governing mechanism sensitive to the speed of the turbine, Which moves a plurality of tapered controller devices.

15. A governing mechanism for elasticfluid turbines, comprising a plurality of valves controlling the flow of motive fluid, electric means actuating said valves, and governoractuated spirally-tapered controller devices for said means suitably spaced apart.

16. In an elastic-iiuid turbine, a rotating element, nozzles delivering fluid pressure thereto, rotary valves therefor and electromagnetic means for operating said valves in combination with a governing mechanism comprising a generator having its terminals suitably grounded, brushes controlling the circuits to said operating means, and a con- 5 5 troller device which is engaged by one or more of said brushes and serves to close their circult to said generator.

17. In an elastic-Huid turbine, a rotating element, a supply-passage delivering the fluid directly to said rotating element, and a number of slanting transverse partitions disposed only in the delivery portion of said passage and acting to divide the iiuid into a plurality of expanding streams, and means disposed Within the delivery portion of said passage to control said streams independently.

18. In an elastic-fluid turbine, a plurality of nozzles, valves therefor, and mechanism sensitive to the speed of the turbine for controlling said valves independently in groups and synchronously pulsating the corresponding valves in each group.

19. In a elastic-fluid turbine, a plurality of nozzles, valves therefor, operating means for said valves arranged in groups, and a tapering governor-controller device for each group.

f In testimony whereof I aiiix my signature in presence of two Witnesses.

JAMES WiLinusoN.

Witnesses:

VAssAR L. ALLEN, JOHN W. S. JONES.

Images