US2006340A

US2006340A - Hydraulic machine

Info

Publication number: US2006340A
Application number: US705858A
Authority: US
Inventors: Baumann Johannes
Original assignee: JM Voith GmbH
Current assignee: JM Voith GmbH
Priority date: 1933-01-10
Filing date: 1934-01-09
Publication date: 1935-07-02
Anticipated expiration: 1952-07-02

Description

July 2, 1935. J. BAUMANN HYDRAULIC MACHINE Filed JanY 9, 1954 2 Sheets-Sheet l N N A M U A ma T5 ma VN mN A H OY JB annui@ IW\; 7

A A y 03mm ATTORNEY July 2, 1935- J. BAUMANN HYDRAULIC MACHINE Filed Jan. 9, 1934 2 Sheets-Sheet 2 INVENTOR .JoHAmsy BAUMANN www EMM- ATTORNEY Patented July z, 193s UNITED STATES PATENT oFFicE HYDRAULIC MACHINE Voith, and Hanns Voith Application January 9, 1934, Serial No. 705,858 In Germany January l0, 1933 2 claims. (ci. 253-141) This invention relates to improvements in the I 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 bladesV are hollow.

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

Another object of the invention is to provide an improved hydraulic machine ofthe 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,l 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 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

Figui is a section taken on the line 4-4 of Fig. 3.

Heretofore, in the construction of impellers or .runners lof the Kaplan Vtype of hydraulic machines, it has been customary to form the impeller blades in one piece. 'I'he blades were usually formed-from castv iron, ca'st 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 type` of hydraulic turbine having impeller blades as possible, so as to keep the weight of thewhole machine down to a minimum.

Furthermore, it is also of-advantage to so form the impeller blades as to reduce the corrosive action on the surfaces of the blades as much as 5 possible. v

Heretofore, by using expensive materials such as cast steel and' bronze, it has been possible to substantially eliminate cavitation, pitting, and corrosive action, but it has been found that the 10 use of these expensive materials hasadded materially to'the cost of hydraulic machines having 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 eiiicient by constructing the blades partly of cast or forged metal and partly of structural and plate steel. 20 In this way the portions or surfaces of the blades subjected to cavitation, pittingand 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 25 expensive material, such as beams, girders and plate steel.

Furthermore, impellers made according to the present invention will have less weight than the' impellers made formerly with solid cast blades, 30 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.

Another advantage of the present invention is 3 that it is possible to use suitable non-porous materials for the, surfaces of the impeller blades, which materials usually are more resistant to vcorrosive 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 operations will 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.A 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 varies I2, only a portion of which are shown. The lower portion I3 vof the turbine casing forms 55 an axially directed chamber in which peller I4 operates. I

The hub of the impeller I4 is fixed to the lower end of the shaft I5 which is journalled in a suitable bearing I6 mounted in the turbine casing.

Any suitable type ofsetting may be used for the turbine installation, a concrete setting I1 being shown in the present instance. The portion of the setting below the turbine forms a draft tube 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 2I, both of which edges extend from the hub of the impeller I4 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 26 which is disposed in a suitable recess 21 in the impeller hub I4. Y

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 blade and links 3| which pivotally connect the arms on the different blades to a cross head 32.

. 'I'he'oross 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 34 is bolted or otherwise removably secured to the lower end of the hub of the impeller I4.

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 I5 and is adapted to be operated by suitable the immeans (not shown), such for instance as that shown in United States Patent #1,937,772 granted December 5, 1933 to Daniel J. McCormack, for Hydraulic turbine.

As shown in Figs. 3 and 4, the main body of each blade I9, its hub 26, and its trunnion 23, are preferably formed from cast metal, such as steel, iron or bronze.

The blade I9 is preferably made in two sections 6I and 62, adapted to be joined together in the manner shown in Fig. 4.

'I'he upper or pressure side 5I of each section of the blade is made comparatively thin and depending from such surface is a plurality of substantially radially disposed ribs 52 and a plurality of substantially circumferentially disposed ribs 53'. As shown, the

ribs

52 and 53 may be arranged at right angles to each other, and if so desired the ribs 52 may parallel the abutting edges 63 and 64 of the sections 6I and 62, respectively, said edges being similar in form to the ribs. Y

Forming the under or non-pressure sides of veach section of the blade are

steel plates

65 and 66, the plate 65 covering the section 6I and the plate 66 covering the section 62.

The marginal edges of the

plates

65 and 66 are disposed in

recesses

61 and 68, respectively, which are formed around the periphery of the sections 6I and 62. The

plates

65 and 66 may be permanently attached to the

ribs

52 and 53, as well as to the periphery ofthe sections 6I and 62, by welding, or by any other known means.

At suitable intervals the adjoining edges or,

ribs 63 and 64 are formed with alined openings, through which are passed bolts 10 for fastening the two sections 6I and 62 together.

By forming the blades I9 in the above described manner, the weight of the blades will be considerably less than the weight vof similarly size'solid cast blades. Furthermore, by forming the blades in sections, the blades can be disassembled for shipping purposes, thereby materially reducing the weight of the turbine. The several sections of the blades can be easily assembled at the site of installation of the turbine. In this manner turbines of abnormal size can be commercially produced, since it is possible to form a portion of the turbine in sections of a size convenient for transporting to the site `of installation.

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 claims. v

Having thus described my invention what I claim isz- 1. An impeller for hydraulic machines of extraordinary large size in which it is impracticable to ship the impeller as a whole from the place of manufacture to the site of installation, comprising a hub, a plurality of blades projecting from the hub, each of said blades comprising two sections, one blade section being mounted on the hub and having a size, together with the hub, which provides a structure practical to ship from the place of manufacture to the site of installation, the second blade section having a size and configuration adapted. when joined to the first blade section, to form with the first blade section a blade of the desired configuration. each blade including an entrance edge, a discharge edge, and an outer peripheral edge joining the entrance edge and discharge edge, the entrance edge and a portion of the outer peripheral edge of each blade being formedA on one blade section and the discharge edge and the remaining portion of the outer peripheral edge being formed on the other .blade section, each of said blade sections having a main body portion formed from cast metal. the cast portion constituting the pressure side and edge portions of said blade,'said blade sections being adapted to be joined together along a diagonal line extending outwardly from the hub of the impeller to the outer peripheral edge of the blade, a plurality of ribs depending from the pressure side of each of said blade sections. said ribs'oonstituting reinforcing means for the blade, said ribs being arranged in parallel rows at right angles to each other with ribs extending outwardly from the inner portion of the blade parallel to the dividing edges of the two blade sections and other ribs disposed at right angles thereto, the .ribs along the adjoining edges of the blade sections constituting flanges, bolts passing through said flanges for fastening the two blade sections together, and plates covering said ribs and constituting the non-pressure side of the blade.

traordinary large size in which itis impracticable to ship the impeller as a whole from the place of manufacture to the site of installation of the machine, comprising a hub, a plurality of blades ,rotatably mounted in the hub, each of said blades comprising twosections divided along a line extending at an angle from the outer peripheral edge of the blade to the hub, one blade section having a trunnion formed thereon by which the blade is pivotally mounted in the hub of the impeller, said trunnion section of the blade being adapted to be assembled with the hub at the place of manufacture, and these blade sections, .together with the hub providing a structure of a size which is practical to ship from the place of manufacture to the site of installation, the second lposed at right angles tiono the outer peripheral edge of each blade being `formed onone blade section. and the discharge edge andthe remaining portion of the outer peripheral edge beingformed on the other blade section, each of said blade sections having a main body portion formed from cast metal, the cast portion constituting the pressure side and edge portions of'said blade, a plurality 'of ribs depending from the pressure-side of each of said blade sections, said ribs constituting means for reinforcing the blade, said ribs being arranged in parallel rows at right angles to each other with ribs extending outwardly Afrom the inner portion of the blade parallel to the dividing edges of the two blade sections and the other ribs disthereto, the ribsalongthe adjoining edges of the blade sections constituting flanges, bolts passing through said ilanges for fastening thetwo blade'sections together, and

non-pressure side of the blade.

JOHANNES BAUMANN.

Aplates covering said ribs' and constituting the 20