US2015332A - Hydraulic machine - Google Patents

Description

Sept. 24, 1935. J. BAUMANN4 HYDRAULIC MACHINE Filed Jian. 9; 1934 2 sheets-sheet 1 INVENToR JOHANNES BAUMANN BY l WZSKOQMNst-L- -ATTORNEY Sept. 24, 1935. J. BAUMANN HYDRAULIC MACHINE Filed Jan. 9, 1954 2 Sheets-Sheet 2 INVENTOR JOHANNES BAUMANN y BY M Q. hmm- ATTORNEY Patented Sept. 24, 17935' HYDRAULIC MACHINE JohannesA Baumann, Heidenheim-on-the-Brenz, Wurttemberg, Germany, assign'ors to J. M. Voith, Heidenheim-on-the-Brenz, Germany, a copartnership composed of Walther Voith, Hermann Voith, and Hanns voith Application January 9, 1934, Serial No. 705,857 In Germany January 10, 1933 1 Claim.

construction of hydraulic machines, such for instance as pumps, hydraulic turbines, and the like. and more particularly to improvements in the construction of the impellers or runners of such machines.

An object of the invention is to provide an improved construction-of the impeller or runner of a hydraulic machine of the Kaplan type having movable blades.

Another object of the invention is to provide an improved construction of hydraulic machines, in which the impeller or runner blades are made of composite material, partly of cast or forged metal and partly of plate and structural steel.

Another object of the invention is to provide an improved hydraulic machine of the character mentioned, in which the impeller blades are hollow.

Another object of the invention is to provide an improved light weight blade for impellers of hydraulic machines. f

Another object of the invention is to provide an improved hydraulic machine of the charactery mentioned, which" is simple in construction, andl reliable and exact in function under all condi: tions of service.

The invention also comprises certain new vand useful improvements in the construction, arrangement and combination of the several parts of which it is composed as will be hereinafter fully described and claimed. l

In the accompanying drawings:-.

Figure 1 is a view partly in section of a Kaplan type of hydraulic turbine having impeller blades lconstructed according to the present invention;

Fig. 2 is a vertical section of the impeller, showing the construction of the parts within the hub thereof;

Fig. 3- is a section taken on .the une 3 3 -or Fig. 2, showing one of the impeller blades in plan,

a portion ofthe blade beingbroken away to show the underlying structure; and

Fig. 4 is'a section taken on the line ,4 4 of Fig. 3.

Heretofore, in the construction of impellers or runners of the Kaplan type of hydraulic ma# chines, it has been customary to form the impeller blades in one piece. The bladesvwere usually formed from cast iron, cast steel, bronze, and other suitable material. A

In the case of hydraulic machines having impellers of considerable size or area., it is of advantage to reduce the weight of the blades as much as possible, so as to keep the weight of the whole machine down to a minim This invention relates to improvements in the f Furthermore, it is also of advantage to so form v the impeller blades as to reduce' the corrosive action on the surfaces o f the blades as much as possible.

Heretofore, by using expensive materials such 5 as cast steel and bronze, it has been possible to substantially eliminate cavitation, pitting, and corrosive action,- but it has been found that the use of these expensive materials has added materially to the cost of hydraulic machines having 1o solid cast' impeller blades. Therefore, the use of solid cast blades is uneconomical for very large hydraulic machines. According to the present invention the impeller blades of very. large hydraulic machines can be made lighter in weight and more elcient by constructing the blades partly of cast or forged metal and partlyof structural and plate steel. In this way the portions or surfaces of the blades subjected to cavitation, pitting and corrosion can be formed from expensive material, such as cast or forged steel, while the remaining portions and surfaces of the blades can be formed from less expensive material, such as beams,

`girders and plate steel.

pressent invention will have less weightthan the impellers made formerly with solid cast blades, and therefore smaller bearings can be employed for both the impeller shafts and 'also the trun- 30 nions of the impeller blades which are journalled in the impeller hub.

Another advantage of the present invention "is that it is possible to use suitable non-porous materials for the surfaces of the impeller blades, which materials usually are more resistant to corrosive action than the cast metals or mate- -rials heretofore used.

Also, by employing plate steel for forming a portion of the blades', the warping of the blades 40 due to casting, will be eliminated, and a smoother surface requiring no finishing or polishing operations will be had. A

The preferred embodiment of the invention is shown in connection with the well known Kaplan type of hydraulic turbine. v

Referring to the drawings and especially to Figs. 1 and 2, the turbine comprises a casing Il which forms a peripheral water inlet in which are mounted an annular series of wicket gates or guide vanes l2, only a portion of which are shown. The lower portion I3 of the turbine casing forms an axially directed chamber in which the impeller Il operates..

The hub of the impeller I4 is iiixed the lower 1' end of a shaft I5 which is joumalled in a suitable bearing I5 mounted in the turbine casing.

Any suitable type of setting may be used for the turbine installation, a concrete setting |1 being shown in the present instance. lThe portion of the setting below the turbine forms a drafttube i8 into which the water is discharged from the impeller.

As shown, the turbine is of the adjustable blade type, and a suitable number of blades I9 are rotatably supported in the hub of the impeller I4 and project radially therefrom. Each blade I9 has an entrance edge 20 and a discharge edge 2|, both of which edges extend from the hub of the impeller Il outwardly to the outer edge 22 of the blade.

As shown in Figs. 2 and 3 the inner portion of each blade I9 is formed with a trunnion 23 which is journalled in bearings 24 and 25 supported in the hub of the impeller I4.

The trunnion 23 is formed with a collar or hub which is disposed in a suitable recess 21 in the impeller hub I4.

A suitable packing 28 is mounted in the recess 21 behind the collar or hub 26, to seal the joint between the blade and the hub of the impeller I4 and prevent the entrance of water into the interior of the impeller hub.

Means are provided for simultaneously rotating all of the blades I9 and for maintaining them in equal angular relationship, such means comprising preferably an arm 30 rigidly xed on the trunnion 23 of each bladel and links 3| which pivotally connect the arms on the different blades to a cross head 32.

The cross head 32 is guided to reciprocate in a direction axially of the impeller by guide pins 33, which` are mounted in the hub of the impeller in the manner shown in Fig. 2.

As shown in Figs. 1 and 2 a cap 3l is bolted or otherwise removably secured to the lower end of the hub of the impeller Il.

The cross head 32 is bolted or otherwise fixed to the lower end of an operating rod 35 whichv metal and structural and plate steel.

The trunnion 23, collar or hub 26 and the portions 5|, 52 and 53 of the blade can be forged from steel, or if so desired they can be cast. 'Ihe portion 5| constitutes a cantilever from which the portions 52 and 53 project. The entrance edge 2l is' formed on the portion 52, and the discharge edge 2| is formed on the portion 53.

The outer peripheral edge 22 of the blade is formed on a beam 5l, which extends from the tip of the portion 52 to the tip of the portion 53, the ends of said beam being suitably joined to the tips of said portions 52 and 53, by welding or in any other suitable manner. 5

Arranged in the space between the portions I, 52, 53 and 5l, are reinforcing means in the fo of a plurality of radially disposed beams 55 and a plurality of clrcumferentially disposed beams 56. 'Ihese beams may be joined together in any 10 suitable manner, such as by welding, to provide a rigid structure.

Disposed on top of the beams 54, 55 and 55, and constituting the upper or pressure side of the blade, is a steel plate 51, and disposed on4 the 1'5 lower side of said beams and constituting the non-pressure or vacuum side of the blade, is a steel plate 53.

The plates 51 and 53 may be permanently' attached in place by welding or by any other known means.

By forming the blades I9 in the above described manner, the weight of the blades will be materially less than the weight of similar size solid cast blades. Furthermore, the surfaces of the blades subject to corrosion and cavitation or. pitting are formed of forged steel, while the balance of the blades are formed from smooth, nonporous plate steel, thereby enhancing the finish of the blades and increasing the efficiency thereof. lo

While one illustrative embodiment of the invention has been described in detail, it is not my intention to limit its scope to that embodiment or otherwise than by the terms of the appended claim. I

Having thus described my invention what I claim isz- An impeller comprising a hub. a plurality of movable blades projecting from the hub, a trunnion formed on each blade, means for journalling 40 the trunnions in said hub, a collar formed on the outer portion of each trunnion, a recess formed in the hub for said collar, a cantilever inner portion formed on the body of each blade adjacent said collar, spaced arms projecting outwardly 45 from the cantilever inner portion, one of said arms constituting the entrance edge of the blade and the other arm constituting the discharge edge of the blade, a beam connecting the extremities of said arms and constituting the outer peripheral 50 edge of each blade, a plurality of divergins radially disposed beams extending from the inner portion of each blade outwardly to said outer peripheral edge, a plurality of substantially circumferentially arranged beams disposed between 55 each of said radially disposed beams and extending from the entrance edge tothe discharge edge of each blade, and plates superposed on said beams and constituting respectively the pressure and non-pressure sides of the blade. 4 00 JOHANNES BAUMANN.

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