US2497508A - Turbine adjustage - Google Patents

Description

Feb. 14,- 1950 AG. M. MICHELL TURBINE ADJUSTAGE Filed April 9, 1948 ANTHONY GEORGEYMALDON MICHELL ATTORNEY.

Patented Feb. 14, 195G TURBINE ADJ UTAGE Anthony George Maldon Michell, Melbourne, Victoria, Australia Application April 9, 1948, Serial No. 19,989

Claims. 1

This invention relates to adjutages for the nozzles of Water turbines of the class in which the infiow takes place in radial planes at the circumference of the turbine wheel. A turbine of this class has been described in the applicants expired Patent No. 760,898, dated May 24, 1904.

In many cases in which water turbines are used, particularly in small installations, it is necessary, in order to enable a demand for power to be immediately met at any time, to keep a turbine unit running throughout the night and at other hours when little or no power is normally required. It is consequently important, in such cases, that the efficiency of the turbineadjutage shall be as high as possible when producing no useful power, or only a small amount of power, as well as when operating at, or more nearly at, its full capacity. This feature of design is especially important when the total water supply is limited and is conserved by storage. The turbine adjutage which is the subject of the present invention has been designed to meet such conditions.

In the accompanying drawings, Fig. 1 is a longitudinal section of an adjutage constructed according to the invention, and shows also a segment of the turbine-wheel in external view. In this view the adjutage is closed.

Fig. 2 is a longitudinal section of the adjutage taken on a plane at right angles to Fig. l on the line IIII of the latter figure.

Figs. 3 and 4 are longitudinal sections taken on the same plane as Fig. 1, the adjutage being shown partially open in Fig. 3 and ahnost fully open in Fig. 4.

Fig. 5 is a cross-section of the adjutage on a plane through the line V-V in Fig. 1.

In Fig. 1 the turbine wheel I, and the nozzle 2, with the adjutage, which consists essentially of the shell 3 and tongue 4, are shown in their correct positions for operation, but with the tongue 4 in the position in which it closes the adjutage. The shell 3 is attached to the nozzle 2 by screws 5 5a, which fasten lugs 6, 6a of the shell to lugs I, la of the nozzle. The mutually meeting surfaces of the shell and nozzle are portions of cylindrical surfaces of accurately equal radii, so that when the parts are secured together the joint between them is water-tight. The interior surfaces 9, 9a of the shell 3 are plane and parallel, and its surfaces I0, I0a conform approximately, but with necessary working clearances, to the periphery of the wheel I.

The tongue 4 has parallel plane sides by which it fits accurately, with a small working clearance,

between the plane surfaces 9, 9a. of the shell 3; it is rotatably mounted in the shell by means of the spindle I I, whose axis is the line 8, 8. The spindle I I is non-rotatably fixed in the tongue- 4, as by key Ila, but is rotatably mounted in the shell 3, as by anti-friction bearings I2, I2a, Fig. 2. An arm is is rigidly attached to the spindle-I I at one of its ends, as by key I4.

The surface 4a of the tongue 4, at its end remote from the spindle I I, is accurately turned to a cylindrical form with axis 8, 8, (which is also the axisof the corresponding cylindrical surface of the shell 3), but with a slightly smaller radius than the latter, so that it has only a small and practically water-tight clearance from the cylindical surface of the nozzle 2 to which it is opposed.

The surface 41) of the tongue 4, is shaped to into the positions shown in Figs. 3 and 4. To prevent the tongue being rotated too far in the opposite direction, so as to bring it into contact with the periphery of the wheel, a pin I5 is passed through holes drilled in the side- surfaces 9, 9a of the shell 3 and through an arcuate slot 40 in the tongue of such circumferential length as to limit the motion of the tongue to the extent required.

A flexible strap I6 is attached to the curved rear surface of the tongue 4, by screw II, as shown in Fig. 1, and a tension is maintained in this strap by a tension-spring I8 attached to the nozzle, as by a clevis I9, so tending always to rotate the tongue about the axis 8, 8 towards the position shown in Fig. 1; in other words, to close the adjutage.

In operation, when the tongue 4 is rotated from the closed position of Fig. 1 (as by a governormechanism of any known construction acting on the arm I3), into a position, such as that shown in Fig. 3, a small jet of water is allowed to flow between the lower lip of the nozzle 2 and the angle of the tongue formed by the intersection of its surfaces 4a and 4b. This jet of water 20, springs clear of the outer surface 4b of the tongue and enters the wheel directly as a free jet without encountering any frictional resistance from such surface. When however by further rotation, in the same direction, of the arm I3 and at 20, Fig. 3, contact over the Surface 41), if al-'-- lowed to occur, would absorb a large portion of its energy. I claim:

1. A nozzle for a water turbine, the outflow end of said nozzle being terminated by anarc of c a concave cylindrical surface and being can structed to form an aperture of fixed dimensionv through said surface, combined with an adjutage comprisingplane parallel sides, a tongue between said sides pivotally supported near one of its ends on an axis spaced from said surface of the nozzle, it other end. being terminated by an arcof aconvex cylindrical surface of the same radius as that of the end of thenozzle, opposed to, matchingand movable over the apertured end of the nozzle to form'therewith an adjustable valve;

2.. A nozzle for a water turbine, the outflow end of said-- nozzle being terminated by an arc of av concave; cylindrical surface and being constructed .to' form an aperture of-f xed dimension. 7

through said surface, combined with an adjutage comprising plane arallel sides; a tongue between said sides pivotally s pported near one of its.

ends on.- an axis spaced fromsaid surface of the nozzle-its other end being terminated by an are 1 ofaconvex. cylindrical surface ofthe same radius as that of the end ofzthe nozzle, opposed to,- matching and movable over the apertured end .1

of. theinozzleto form therewith an adjustable valve, the 'pivotally supported'end of the tongue forming a transverse edge of the-outflow end of the adjutage',-sa3id tongue having-aliquid guiding i surfaceinterconnecting its arcua-te end surface and'sa-id outflow-edges 3.- A nozzlev for a water turbine, the outflow end of: said nozzle being terminated by an arc-of a; concave cylindrical. surface and being-cone structed to ,form anaperture lofifixed dimension" through-said surface, combined with an adjutage' comprising plane parallel sides; a tongue between:

said sides pivotally; supported near one of its; ends on an axisspaced from-- saidsurface of the nozzle, its other end being terminated by an arc of a convex cylindrical surface of the same as that of the etnd of the nozzle, opposed to, matching and movable over the apertured end of the nozzle to form therewith an adjustable valve, the pivotally supported end of the tongue forming a transverse edge of the outflow end of the adjutage, said tongue having a curved liquid guiding, surface intersecting: the apertured end surface of the nozzle, interconnecting its arcuate end surface and said outflow edge.

4. A nozzle for a water turbine, the outflow end of said nozzle being terminated by an arc of a concave cylindrical surface and being con- S-tl-llCtedIO' form an'aperture of fixed dimension through said surface, combined with an adjutage comprisinglplaneparallel sides, a tongue between said sidespivotall'y supported near one of its ends on:an:ax'is= spaced from said surface of the nozzle, its other end being terminated by an arc of a convexzcylindrical: surface of the same radius as that of the-end of the nozzle,-opposed to, matching and V movableover the apertured endnf the nozzle to form therewith an adjustableshut-ofi valve, the

pivotally supported end of the-tongue forming a transverse edge of:- fixedposition of the outflow end-:ofthe .adjutage, said tongue having- .a curved liquid-z guiding surface intersecting the, apertured ,end surface-of theenozzle. at substanti-allyrigh-t angles; interconnecting. :its arcuate. endlsurf-a'ce andits outflow edge. 7

5. 'In combination'with a water turbine wheel,

awnozzlei therefor constructed to forman aper-v ture O'fnfiXed" dimensionran adjutage having a.

shell affixed to thenozzle havinggplane parallel walls disposed on-oppositesides-of the-nozzleaperture and extending,from--. the end of the nozzle over the turbine wheel, a :movable tongue having ,flatsides fittingv said walls and pivoted thereto near one ofi-ts ends-on? an. axisspaced fromthe: endof thewnozzle; the -otheroend of the tongue extending tothe nozzle: to form with 1 the aperture thereof an adjustable' shut-offvalve, therside of the :shell: adjacent: the turbine wheelrbeingaopenz,

ANTHONY GEORGE'iMALDQN MICHELL.

REFERENCEsoi'IEfi:

The following refeimces aieof record in the fi-le of this patent:'

UNITED STATES PATENTS Date Number Name

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