US1837569A - Hydraulic turbine - Google Patents

Description

Dec. 22, 1931. L. F. MOODY HYDRAULIC TURBINE Original Filed April 14, 1923 4 Sheets-Sheet l i inlv l lrh ENTOR w, a m

ATTORNEYS gill! Dec. 22, 1931. MOODY 1,837 569 HYDRAULIC TURBINE Original Filed April 14, 1923 4 Sheeis-Sheet 2 ATTORNEY? Dec. 22,1931. L. F. MOCSDY HYDRAULIC TURBINE 4 $heets$heet 3 NTOR ATTORNEYS Original Filed April 14, 1923 L. F. MOODY HYDRAULIC TURBINE Original Filed April 14, 1923 4sheets-s1ieet 4.

- awvwtoz Patented Dec. 22, 1931 UNITED STATES LEWIS Fanny MOODY, or PHILADELPHIA, PENNSYLVANIA HYDRAULIC TURBINE Original application filed April'14, 1928, S erial No. 681,985. Divided and this application filed June 1, 192 5.

Serial No. 83,940. i

This invention relates to hydraulic turbines and particularly to turbines of the react on type and of high specific speed. The ob] ect of the inventionis to provide. such a turb ne which w ll be simple in form and inexpensive and at the same time eflicient in operation.

It has been found particularly with turbines having high specific speed propellertype runners that very high efiic'iencies can be attained, particularly at or near full load and in many installations it is highly desirable to maintain these efficiencies at artial .loads or full loads. In large instal ations with a number of units where the load on each unit is almost invariable, part'gate or overload efiiciencies are not so important; but Where, as in many smaller installations with only a few units, there are apt to be relatively large load variations, 1n such case the so efficiencies at other loads than normal become an im ortant factor.

A urther object of this invention is to provide a turbine in which the effic encies at part gate or overload will be maintained near the efficiency at normal load. This maintenance of efiiiency throughout a large range of performance is attained by providing the runner with blades of simple strong formation adapted for the attainment of high specific' speeds and having an adJuStment of the blade surfaces to a variable angle wlth relation to the flow.

Further objects of the invention particularly in the specific means used to attain these results will be clear from the following spec1- fication takenin connection with the accompanying drawings in which Fig.1 is a vertical sectional view of a turbine illustrating one embodiment of the invention.

Fig. 2 is a plan view of a portion of the turbine shown in Fig. 1, showing the entrance guide vanes.

Figs. 3 and 4 are sectional views of these guide vanes on line 33 and 44 of Fig.2.

Fig. 5 is a view similar to Fig. 1 illustrating a modified form ofturbi-ne.

Figs. 6, 7 and 8 are vertical sectional Views illustrating modified forms of runners.

Figs..9 and 10 are views similar to Fig.1

illustrating modified forms of turbines.

Fig. 11 is a vertical elevational view of governing means showing connections for operating the runner blades, and

Fig. 12 is a view similar to Fig. 1 illustrating a further modification.

( In the specific embodiment of the invention shown in Fig. 1 the invention is illustrated in connection with a vertical shaft turbine installed in an open fiume F. It may however be installed in connection with anydesired intake means and the axis of the runner shaft may be horizontal or at any desired inclination. I

In Fig. 1 the turbine comprises a distributor containing fixed guide vanes 15 which and the walls of the draft tube D. The

guide vane ring and bearing casing may be made interchangeable with a radial, inwardflow distributor and head cover containing the ordinary wicket gates (see Fig. 5), .so that turbines of standard sizes may be furnished with either fixed guide vanes or Wicket 1 gate regulation, as might be desirable in any given installation. When fixed guide vanes 15 are used as shown it is no longer necessary to make these vanes overlap in order that they may close off the flow for regulation purposes, a small number of such vanes 15 can be used widely spaced (see Fig. 2) and thereby the amount of surface exposed to the flow can be reduced with a corresponding reduction in the loss ofhead due to hydraulic surface resistance.

Since in turbines of the high specific speed propeller type here represented the amount of whirl component of the velocity of entrance of the water into the runner is considerably reduced below what would be re- I quired in turbines of lower specific speed, the

water enters at a large angle with respect to i the tangential direction and therefore does not have to be deflected through a large angle.

in admitting it to the runner. A small number of guide vanes is therefore suflicient tov give the required direction. In designing a set of turbines of standard size for :quantity manufacture, the patterns may be arranged to permit the guide vane angle to be adjust- .cover 20 or an extension of the cover, the

ed to'suit the particular range of horsepower and the speed required in any given installation. After the conditions are determined for an installation, the vanes will then be rigidly cast at the proper angle. These vanes may either be connectedby a continuous ring 19 around their outer ends or in some cases each vane could be provided with a pad at the outer end fitting into a socket in the base ring 18, the surface ofthe pad conforming to the contour of the base ring. I

The bearing casing 17 contains the bearing proper16, which is lined with lignum vitae or rubber, suitable for operation in the water.

The bearing is covered with a strainer 20 to keepvforeign matter out of the bearing. In the arrangement shown, a bell crank'f21 is mounted above the bearing cover to transfer the governor motion from rod 22 to a rod 23 carried within the hollow shaft 24 of the runner 25. It maybe desirable in some cases to enclose this bell crank within the bearing point of support of the bell crank being dropped to a lower elevation to make the design more compact.

The runner 25 is of the movable blade type, the regulation being performed by a rotation 0 each blade 26 on an axis contained in a meridian plane, that is, a plane contain-.

ing the turbine axis. As shown, the vane pins 27 are mounted in ball bearings 28, but this is not, of course, essential, although it may be advantageous particularly when the head'is relatively high. 'Each vane stem 27' carries an arm 29 connected through universal joint 30 to a link member 31 swiveled in a lower member 32 mounted on the vertical rod 23 which passes upward within the hollow shaft 24. The link is pin-connected at the upper end and connected by a ball and socket oint to the block 32 at thelower end, thus providing a universal joint at-eac'h end.

The governor connected to rod 22 can beplaced at any suitable location on the floor of the generator room and the rod 22 can be placed at any suitable angle, thebell crank p 21 to which it is connected beinggiven a cor-.

angle between its arms while the respondin 5 is rotated with the turbine runner governor by a belt and pulley or other suitable connection. This bell crank 21 raises and lowers the central rod 23 within the shaft 24 through afloating governor sleeve and pin connection 33 passing through slots in the shaft 24. The vertical motion of this-central rod 23 rotates all the runner blades 26 components in meridian planes. A shroud ring'is preferably omitted and the blades are of simple rather fiat contour providing high speed propeller type runners. The blade edges are substantially straight lines as projected into meridian planes as shown for instance in Fig.1. Tests which I have made on a runner having adjustable blades of this form show that a very flat efiiciency curve can be secured, that is, the efliciency changes but little over a considerable range of power output corresponding to changes 1n the blade angle. fixed position of the guide vanes 15 is used. If both guide vanes and runner blades are made movable (see Fig. 5) a'very vwide range in capacity of the turbine can be secured and it can be adapted to a wide variation of speed.

'For any given installation, a better form of performance curve can be secured by moving the runnerblades alone than it is possible to secure with fixed runner blades and movable guide vanes.

The fixed entrance guide vanes 15 of Figs. 1 and 2 are shown as varyingin inclination froma more axial direction at their outer ends 15 to a more tangential direction at This is true even when a their inner endsl5" so that the entering flow uided with increasin whirl toward the center.

is g components of his varying angle from the outer tips, of the guide vanes to the inner portions gives the mostv favorable degree of whirl at each point along the discharge edges of the vanes so'that the flow lines proceed along natural whirling paths and the annular column of water is in the form of a freely rotating vortex as it enters the runner.

A'diagonal arrangement of the guide vanes 15 is advantageous in that it reduces the length of path which must be traversed by the water after it reaches the increased velocity of flow through the turbine. This shortened ath permits the hydraulic losses to be reduced. and the entire turbine structure is very compact and involves a. minimum amount of material. With this simplicity of form and inexnensiveness is attainedthe hi 'h efiiciency secured by the coiitrol of the position of the runner blades 26 for different loads and speeds. As ordinarily constructed the runner blades 26 will not be designed to close off the flow completely. They will, however, turn through a suflicient angle to decrease the memes power output to zero. Under this zero output condition a considerable amount of water will still flow'between the blades and it will therefore be necessary to provide head ates at the entrance to the fiume F WhlCh w1ll be closed whenever the turbine is shutdown.

In the embodiment of the invention shown.

in Fig. 5 the adjustment of the runner blad ing 36 is efiected .by moving only a part of the. runner blade, this ad ustable part 37 being the outer portion of the blade mounted rotatably on the-stem or shaft 38 extending through the fixed portion 3% of the blade to 1 within the hollow hub 49 where-it is provided with any desired form of oserating means. Instead of the inclined i e vanes of Figs. 1 and 2 the turbine of ig. 5 has a radial entrance for the flow through the speed ring 41 and wicket gates 42 with an intermediate transition space 43 between the wicket gates and the runner 36 wherein the flow turns toward an axial direction. Since Y in this embodiment of the invention both the movable runner blades and the movable guide vanes are used, theycan be so arranged and theiroperating mechanisms so interconnected that very little drop in efliciency will be secured over a wide range of performance,

the discharge from the runner under a wide Ill ran e of conditions remaining nearly axialturblne with whirl-regaining draft tubes and ably be the desire to omit the draft tube core runner blade regulation.

to provide a central core in the draft tube extending up to and conforming with the runner hub'(in place of the conical cap on the runner) as shown in Fi 5 and 10. In some of the smaller installatlons, it will probfor reasons of first cost. v In cases where both guide vane and runner blade regulation are rovided, it is unnecessary that both sets 9 vanes be moved simultaneousl bythe governor. One set, such as the gui e vanes, can be governor-operated and the other set either hand-o erated or actuated by a slower automatic a justment following and responding to any movement of the primary operating mechanism.

Another modification of this turbine will comprise the use of inclined, movable guide vanes, that is, wicket glass rotatin axescontained inmeri 'an planes,

about ut not parallel to theturbine axis and operated by" mechanism similar to that shown for the 'made movable to serve a In El 6 the runner regulation is produced by mov ng a small portion 44 of the runner blade fi near the outer tips and comprising the discharge portion trance portion 46 remaining fixed. As shown in Fig. 7 instead of'having a free end on this adjustable portion a second stem or trunnion 47 may be provided at the outer end of the movable portion 44' so that this movable portion is supported at both ends and is not overhung as in the other arrangements. This provides a'better support for the movable portion and greater mechanical strength permitting the pins or stems to be made of smaller diameter. In these modifications of Figs. 6 and 7 the most efi'ective part of the blade has been selected for the purpose of regulation and instead of moving the whole section is move and the force required to olperate it is correspondingly reduced. At t 'e same time a suflicient art of the blade is quirements of regulation.

In Fig. 8 an axial flow runner 48 is shown with the outer portions 49 of the blades adjustable on rotatable stems 50 operated from within the hollow hub 51 in a manner similar to the methods shown in the other figures.

One advantage which the preferred diagonal runner has over the purely axial flow runner is that the hub of the dia onal runner can be enlarged so as to give a etter arrangement of the vane the en-.

blade or a large ortion of it, only this small the ordinary reof the operating mechanism with more room fort-he runner blade disks and stems and adjusting means.

he modified form of turbine shown in Fig. 9 is similar to the turbine of-Fig. 1 but instead of moving the adjustable block 32 for the blade links by means of a rod passing up through a hollow shaft, the control rod 23 extends downward through the end of the hub and is moved by a horizontal lever 53 extending across the draft tube and pivoted .at 54 and connected at 55 to the vertical rod 56' extending upward to be connected with the control mechanism. This rod 56 will pass upward through the floor of the generator .roomto the governor. an arrangement similar to that c Fig. 1 but Fi 10 shows differing in the type of draft tube used and 1 in the specific form of the. operating'mechanism-used for the adjustable runner blades. The draft tube D of this figure is of annular form with a central core 71 extendingup within the open lower end of the runner hub 72'.- In the operating mechanism for the adjustable blades the member 72, for actuating the blade levers 29 is placed above them instead of below. Instead of moving this member 7 2 by a central rod in a hollow tur-- bine shaft, it .is connected through vertical rods 73 to a sleeve 74 surrounding the turbine shaft and rotating with it. This sleeve 74 carries a circumferential slot 75 within which is engaged a non-rotatable collar 7 6 which in turn is moved vertically by the two vertical connecting rods 77 and a bell crank 78 placed above. A second sleeve 7 9 is shown at the top which is notin contact with the shaft 24 but merely serves for actuating the rods. This arrangement of Fig. 10 avoids the need for a hollow bored shaft. In Fig. 11 the governor means is shown connected through lever 89 and the intermediate collars to the rod 23, for instance within the hollow shaft 24 of Fig. 1. By this connecting mechanism tipping movements of the bell crank lever 89 are translated into turning movements of the adjustable blades 26.

T5 control the position of the runner blades the lever 89 is connected by link 90 to the piston rod 91 of fluid pressure cylinder 92. The piston of this cylinder 92 has fluid pressure admitted to opposite sides of it by the governor means G according as the increase or decrease of the load makes desirable a shifting of the runner blade inclination.

In Fig. 12 amodified form of turbine is shown in which the inner upper wall is a cylinder 93 and the lower outer wall is a plane surface 94 rounding into a downwardly directed surface of revolution 94, these two walls being joined by diagonal stationary vanes 95. These vanes 95can befew in number and widely spaced to reduce surface resistance and preferably of twisted or warped form to give the correct angle of guidance at every point as shown inFz'g. 2. The runner blades 96 may be diagonally directed as shown and adjustable about radial axes, that is radial with respect to the turbine axis. Each point of the blade tips will then move in aspherical surface about'the intersection of the axes of blade adjustment and the turbine axis. The blades 96 may terminate in a single spherical surface as indiwith relation to the blade tips of the runner shown in Fig.5. It is obvious that this spherical formation of the blade tips may be used with any of the runners shown in the various figures. The wall of the runner chamber such as that indicated at 94 should be tangent to the sphere at about the center of the tip breadth, and should conform as closely as-possible to the sphere to reduce leakage between the tips and the wall. These runner blades may be adjusted by any desired means such for instance as that shown in the turbine of Fig. 9.

The turbine of this invention permits the structural parts to be very simple in form and at the same time combines high specific speed of the runner with a sustained efficiency at all loads. The adjustable runner blades absorb a variable amount of whirl tube capable of regaining the whirling components of the velocity and converting them into effective pressure head at all loads. Such a draft tube adapted to spread and decelerate the flow between inner and outer surfaces of revolution is shown for instance at F in Fig. 5 and may be used with any of the runners shown to convert the variable whirl into pressure head and thus maintain. the efii-v ciency of the turbine throughout a wide variation in the load.

(This application is a division of co-pending application, No. 631,985, for hydraulic turbine, filed April 14, 1923.) J

I claim:

1. A hydraulic turbine comprising a runner having a hub, a water passage for said runner bounded on the outside by an outeii stationary wall and along the inner side by the rotating outer surface of said runner hub, guide vanes at entrance to said passage, said runner having a series of blades sup-- ported by its rotating wall and'each blade being rotatably adjustable upon its axis, and mechanism entirely within the innermost portion of said hub for adjustin said blades, said mechanism including a sli able operating element and connecting means extending upwardly therefrom to said blades.

'2. In a power plant of the character described, a water wheel comprising a hub havinga central hollow portion and a seriesv of unshrouded blades of the propeller type carried thereby and each beingrotatable upon its axis, and a governing mechanism r0- tatable with said wheel and having connection within said central hollow portion with said blades at their inner ends at a point substantially in alignment with the blade axis thereby to change the pitch of the blade faces to maintain a uniform speed of said wheel, said connection including a reciprocable member rotatable with said runner, and means extending upwardly from said re I ciprocable inemberfor connecting the blades therewith.

3. In combination with a water wheel comprising a series of blades of the propeller ings and within the innermost portion of saidhub, and means for actuating said crank arms including a reciprocating rod extending through saidhousing and connections extending upwardly from the lower end of said rod to said crank arms.

.4. In combination with a water wheel com prising a series of blades of the propeller type, a housing constituting a runner hub and having bearings for supporting said blades for rotation upon their axes, of means tion of sai I said bearing for rotating said blades including crank arms connected to said blades on the inner side of and within the innermost porhub, meansv for actuating said crank arms including a reci rccating rod, and connecting means exten ing upwardly from said rod to said crank arms whereby said bearing said blades are disposable in the upper end in ing a series of blades of the pro eller a housing constituting a runner ub an pro- .vided with blade supporting bearings each of said blades having a shaft Journaled in its respective bearing, means for rotating said blades, including a crank arm connects to the inner'end of each shaft, and a reciprocating rod operatively connected to said crank arms by members lying 1n planes which everywhere are inclined to the runner axis, and a shaft for supporting said hub I having a bore hrough which said rod extends.

6. In a hydraulic turbine the combination with fixed guide vanes adapted to impart a whirl to the entering flow, of a runner receiving said flow axially and with inward-- components, said blades being adjustable.-

around axes inclined to the runner axis to different angles with relation to said flow, and a means for adjusting said runner blades while the runner is rotating comprising an axiallyniovable rod. 7

7. In a hydraulic turbine the combination with fixed guide vanes ada ted to impart a.

whirl to the entering flow, o a runner receiv- Y ing said-flow axially and with inward components, said blades being adjustable around axes inclined to the runner axis to difierent angles with relation to said flow, and a means for adjusting said runner blades while the; runner is rotating, comprising a governor controlled member and. connections between said member and said blades,.said connections having an axially movable rod rotating with therunner. j p

8. In' a hydraulic turbine the combination 7 with a runner havin blades rotatably adtween said. rod and said shaft hollow bored shaft carrying said runner, operating means for said blades comprising a centrals'lidable rod within said shaft, and means for transferring from outside said shaft to said rod a relative axial motion beduring the rotation of said runner.

9. A hydnaulic turbine comprising a runner having lunshrouded runner blades :0-

. axis. 5. In combination, a water-wheel compris- .tending outwardl of blades of the propeller type, a tapered tatable around axes extending outward from the runner, and operating means for mov ng said blades comprising a bell crank carrying an axially movable sleeve connected in turn to a slidable rod withinthe runner shaft so as to transfer motion from outside of said shaft to said rod while said runner is rotat- 10. In a hydraulic turbinethe combination with a runner having blades rotatably adjustable around axes inclined to the runner axis, of operating means for adjustin said blades comprisin a member slidably justable relative to t e runner along the runner 11. In a hydraulic turbine, in combination, a runner having blades rotatably adjustable around axes inclined to the runner axis, a runner shaft having a bore extending therethrough, and operating means for adjusting 5 said b ades comprising a rod di osed within Y said bore and axially slidable erethrough.

12. In a hydraulic turbine the combination with a runner havin blades rotatably adjustable around axes inclined to the runner-9o I axis during therotation-of the runner, of operating means for adjustingsaid blades comprising a-member slidably adjustable relatively to the runner along the runner axis.

13 In a hydraulic turbine the combination with a runner having blades rotatably adjust able around axes inclined to the runner axis during the rotation of the runner, of operatin means for adjusting said blades comprising a member slidably adjustable relatively to the runner about the runner axis said member beingconnecte'd to each of sai blades in similar manner.

14. In a hydraulic turbine the combination with a runner having unshrouded blades extending outward from a central hub and rotatably adjustable about axes inclined to the runner axis during the rotation of the runner, of operating ,means' for adjusting said blades comprisinga member axially adjustable. relatively to the runner along the runner axis.

15. In a hydraulic turbine the combination with a runner havin unshrouded blades exrom a central hub and rotatably adjusta le during the rotation of the runner about axes inclined to the runner Y axis, of operating means for adjusting said blades comprising a member co-axially movjustablefabout axes inclined to the runner axis during the rotation of the runner, of a able relative to the runner axis androtatable 120 with said runner, said member being connect-' ed to each of said blades in similar manner.

16; In a power plant of the characterdescribed, a water wheel. comprising a series 125 housing having bearin in which said blades are rotatably mounte a hollow shaft connected with said housing, governing mechanism rotatable with said shaft, a rod in said shaft connected with said governing mechahousing between said head and crank arms to rotate said blades by the movement of said rod. e

17. In a power plant of the characterdescribed, a water wheel comprising a series of blades of the propeller type, a tapered.

housing having in the enlarged end thereof hearings in which said blades are rotatablymounted on axes inclined to the runner axis, a hollow shaft connected with said housing,

governing mechanism rotatable with said shaft, a rod in said shaft connected with sa d governing mechanismwhereby movement in opposite directions is adapted to be imparted to said rod, a crank arm connected with each blade, a head connected with said rod in proximity to said crank arms and in the smaller end of said housing, and connections extending upwardly between said head and crank arms to rotate said blades by the movement of said rod.

18. The combination in a hydraulic turbine comprising a flow passage and a'runner having a hub with a central'hollow portion, adjustable blades carried by said hub and rotatable on axes inclined to the runner axis, operating means adapted upon actuation to adjust said blades including crank arms connected to the inner ends of said blades within said central hollow portion, and means extendin upwardly and connected to said crank arms or actuation thereof, and a shaft for supporting-said runner connected thereto at the upper portion thereof and without passing through said central hollow portion. n

19. The combination-in ahydraulic-turbine comprising a flow passa e and a runner having a hub with a central ollow portion,

adjustable blades carried by said hub and rotatable on axes inclined to the" runner axis,

low portion of said runner shaft and opera supported in said bearings and extend-ing in wardly within said hollow portion, crank arms secured to the inner ends of said shafts,

an axially movable rod having upwardly extended connections with said crank arms to effect simultaneous operation of said blades,

and a shaft for supporting said runner being connected to said runner hub at the upper portion thereof thereby to permit the central hollow portion to be substantially free to house said crank arms and the operative cona central hollow portion and bearings formed in the hub wall surrounding said hollow portion, a hollow shaft for supporting said runner, blades rotatably supported in said bear ings and each blade having an operating member extending within said hollow portion, a reciprocating rod extending through the hollow portion of said runner shaft and down into the lower part of said hollow por-' tion, and elements connected to the lower end of said reciprocating rod and extending up wardly for connection to said blade operating means.-

22. The combination ina high specific speed propeller tvpe hydraulic turbine comprising means forming a flow passage through which fluid symmetrically flows with respect to the turbine axis, and a runner dis posed in said passage and having a hub with a a central hollow portion and bearingsformed in the hub wall surrounding said hollow portion, a hollow shaft for supporting said runner, blades rotatably supported in said bearings and each blade having an operating member extending within said hollow nor-' tion, crank arms carried by the inner ends of said blade operating members within the hollow portion of said hub, an operating rod extending through the hollowv portion ofsaid runner. shaft and down into the lower part of the hollow portion of said hub, and elements connected to the lower end of said rod and extending upwardly for connection to said crank arms.

LEWIS FERRYMOOD Y.

tively connected to said crank. arms by con-,

necting members lying in planes which are everywhere inclined to the runner axis.

20-. The, combination in a hydraulic turbine comprisingmeans forming a flow pas sage, and a runner disposed therein having a hub with a central hol ow portion and bearings formed in the wall surrounding said hollow portion, blades having shafts rotatably

Images