US2006339A - Hydraulic machine - Google Patents

Description

July 2, 1935. J, BAUMANN HYDRAULIC MACHINE Filed Jan. 9, 1954 2 Sheets-Sheet 1 IIIIIIII INVENTOR JOHANNES BAUMANN BY W "25*.

ATTORN EY July2, 1935. J. BAUMANN A 2,006,339

HYDRAULI C MACHI NE Filed Jan. 9, 1954 2 sheet -sheet 2 INVENTOR JOHANNES BAUMANN Patent d July 2, 1935 UNl-lED "STA-TE HYDRAULIC MACHINE Johannes Baumann, Heidenhelm-on-the-Brenz,

Wurttemberg, Germany, assignor to J. Hcidenheim-on-the-Brenz, Germany,

M. Voith, a copartnership composed of Walther Voith, Hermann Yolth, and Bonus Voith Application" January 9, 1934,

BIG

Serial No. 705,856

ermany January 10, 1933 .1 Claim. (Cl. 253-141) This invention relates to improvements in the 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 runnerblades 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.

Another object of the inventionis to provide an improved hydraulic machine of the character mentioned, which is simple in construction, and reliable and exact in function under all conditions of service.

The invention also comprises certain new and 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.

In the accompanying drawings:-

. Figure 1 is a view partly in section of a Kaplan type of hydraulic turbine having impeller blades constructed 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 line 3- 3 of Fig.

2, showing one of the impeller blades in plan; a

portion of the blade being broken away to show the underlying structure; and

Fig. 4 is a section taken on the line H of Fig. 3. Heretofor'e, in the construction of impellers or runners of the Kaplan type of hydraulic machines,

it has been customary to form the impeller blades in one piece. The blades were usually formed from cast iron, cast steel, bronze, and other suitable material.

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 downtoaminimum.

way the portions or Furthermore, it is alsocf advantage to so form the impeller blades as to reduce the corrosive action on the surfacesof the blades as much as possible. I

-Heretofore, by using expensive materials such 'ascast 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 solid cast impeller blades. Therefore, theme 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 efficient by constructing the blades partly of cast or forged-metal and partly of structural and plate steel. In this 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 fromless expensive material; such as beams, girders and plate steel.

Furthermore, impellers made according to the present invention will have less we ght than the.

impellers made formerly with solid cast blades,

and therefore smaller-bearings can be employed for both the impeller shafts and also the trunnions of the impeller blades which are journalled in the impeller hub. 1

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

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

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

Referring to the drawings and especially to Figs. 1 and 2. the turbine comprises a casing II which forms a peripheral water inlet in which are mounted an annular series of wicket gates or guide vanes i2, only a portion of which are shown. The lower portion l3 of the turbine cas-' ing forms an axially directed chamber in which the impeller ll operates.-

lower end of a shaft l5 which is journalled in .a suitable bearing l6 mounted in the turbine casing.

Any suitable type of setting may be used for the turbine installation, a concrete setting I! being shown in the present instance. The portion of the setting below the turbine forms a draft tube I 8 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 l9 are rotatably supported in'the hub of the impeller I4 and project radially therefrom. Each blade l9 has an entrance edge 20 and a discharge edge 2|, both of which edges extend from the hub of the impeller l4 outwardly to the outeredge 22 of the blade.

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

The trunnion 23 is formed with a collar or hub 26 which is disposed in a suitable recess 21 in the impeller hub ll.

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 rotat.

ing all of the blades l9 and for maintaining them in equal angular relationship, such means coniprising preferably an arm 30 rigidly fixed on the trunnion 23 of each blade and links 3| which pivotally connect the arms on the different blades to a cross head 32.

The cross head 32 is guided toreciprocate 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 34 is bolted or otherwise removably secured to the lower end of the hub of the impeller l4.

The cross head 32 is bolted or otherwise fixed to the lower end of an operating rod 35 which extends upwardly through the hollow impeller.

shaft l5 and is adapted to be operated by suitable means (not shown), such for instance as that shown in United States Patent #1,937,772

granted December 5, 1933 to Daniel J. McCr-- mack, for Hydraulic turbine.

As shown in Figs. 3 and 4, the main body of each blade l9, its collar or hub 26, and its trunnion 23 are preferably formed from cast or forged metal, such as steel, iron or bronze.

The upper or pressure side it of each blade is made comparatively thin and depending from such surface is a plurality of substantially radi ally disposed ribs 52 and a plurality of circumferential ribs 53. The ribs 53 conform generally to the contour of the outer and inner edges 22 g and 55 respectively,- of the blade.

Forming the under or non-pressure side of each blade I9, is a' steel plate 55. The marginal edges of the plate 56 are disposed in a recess 51 formed around the periphery of the blade. Plate 55 may be permanently attached to the ribs' 52 and 53,

as well as to ,the periphery of the blade, by

welding, or by any other'known dicated at 60, Fig. 4.

By forming the blades IS in the above described manner, the weight of the blades will be materially less than the weight of similarly sized solid means, as incast blades, as will be readily understood. In

this way turbines of abnormal size can be more I the hub,.each of said blades having a trunnion journalled in the hub, and a blade portion composed of cast metal integral with said trunnion and constituting the edge portions andpressure side of said blade, a plurality of radially disposed depending ribs and 'a plurality of substantially circumferentially disposed depending ribs integrally formed with the cast portion of each blade, said ribs constituting means for reinforcing the blade whereby the weight of the blade is substantially reduced, 9. plate covering said ribs and constituting the non-pressure side of the blade, each blade having a comparatively thick entrance edge and a relatively thin. discharge edge, the pressure and non-pressure sides of each -blade gradually converging from the entrance edge toward the discharge edge of each blade, said depending ribs progressively decreasing in height from the entrance edge to the discharge edge of each blade, a depression formed in the periphery of the underside of each blade to provide a recess for'the platefand means for attaching the plate in the recess and to each of the depending ribs.

JOHANNEB BAUMIANN.

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