US930858A

US930858A - Covering for blade-carrying elements.

Info

Publication number: US930858A
Application number: US43508008A
Authority: US
Inventors: Francis Hodgkinson
Original assignee: Westinghouse Machine Co
Current assignee: Westinghouse Machine Co
Priority date: 1908-05-26
Filing date: 1908-05-26
Publication date: 1909-08-10
Anticipated expiration: 1926-08-10

Description

F. HODGKINSON. COVERING FOR BLADE CARRYING ELEMENTS. APPLICATION FILED MAY 26, 1908.

930,858. Patented Aug. 10, 1909.

9 43;? tag 'so that: it will protect the surfaces of the 'UNITn sTATEs PATENT orrion."

rnAncis-nonoicmsoN, or'nnsnwoon PARK, PENNSYLVANIA, 'Assienon 170 THE WESTINGHOUSE MACHINE ooMrANY, A coRronAT oN or PENNSYLVANIA.

cov'nnmo non BLADE-GABIYING murmurs.

Specification of Letters Patent. Application filed ma as, 1908. serial No. 435,080.

Patented Au 10, 1909'.

Invention in Protective Covering for Blade Carrying Elements, of which the following is a specification.

This invention relates to elastic fluid turbines and more particularly to means for protecting the exposed surfaces of the bladecarrying elements of the turbine from the corrosive and erosive action of the motive fluid.

An object of this invention is the production of simple and eflective means for seblade-carrying elements, A

a The corrosive and erosive action encountered in elastic fluid turbines may result from chemical impurities in the boiler feed water, such, for instance, as organic or inorganic acids or it may result from the corrosive'action of the distilled water, that is the water of condensation, and the erosive "action of the motive fluid and the Water of condensation. Whatever the cause the fact remains that the exposed surtaces of the blade-carying elements are at times/corroded and even badly pitted. The cast iron casingof the turbine (the stationary bladecarrymg element) is usually morelactively attache and for this reason the primary ob ect of my invention is to provide a pro- I tective lining for the casing, but'I desire it .its broad sense; that is, to. include both the to be understood that I contemplate pro viding a protective cover and means for securing it in place on the blade-carrying element which will be equally elfective on the rotor orstator element. I

' Throughout this specification and in the claims I will employ the word blade in rotating blades and the. stationary blades.

. In the drawings accompanying this application and forming a part thereof: Figure 1 is a fragrnental section of a rotor or rotating blade-carrying element and discloses an embodiment of my invention; Fig. 2 is a fragmental section of the stator or stationary blade-carrying element of the turbine and is taken along the line A-A otFi-g. 3;

F isa fra mental longitudinal section of a portion '0' the stationary blade-earrying element; Fig. 4 is a plan view of an embodimentof my invention in connection with the rotor element; F ig.- 5 is a perspective view of a detail of my invention; Figs. 6, 7

and 8 are respectively end, sideand end ele-- vations of amodified form of a detail of any invention; and, Fig. 9 is a fragmental longitudinal section of a bladerarrying element and discloses a method of locking the blades in .the blade-mounting slots.

The blade-carrying element dot the turbine is provided wit-h a plurality of blademounting slots 7 in which blades and intermediate spacing pieces 9 are secured. Each blade is provided near its base with a hole 10 which extends transversely therethrough and each spacing piece is provided with a corresponding hole, so located with n the piece as to register with the hole 10 in the blade when located in the blade-mounting slot adjacent to the blade. V

Blades and alternate spacing pieces are assembled in segmental strips or sections by mounting a number of the blades and intermediate spacing pieces on' a binder wire 12,- which is threaded through the holes providedin the base portionsof the blades and spacing pieces.

After the blades and spacing pieces are in place on the wire'the ends ofthewire may be riveted over to secure them' in place and also to form a fairlyrigid segmental strip.

The outer or free ends of the blades are provided with comma-shaped holes 13 through which a binding wirela of commashaped cross section extends. The binding wire is secured to the blades and is caused to space the outer or free ends of the blades by having the tail-shaped fin 15, with which it is provided, sheared and bentv over :between adjacent blades. This construction, together with the wires 12, iorms rigid blade strips which may be assembled at any time riorto mounting them in the turbine and which may be handled without the danger of becoming damaged. r

After the blades and the spacing pieces are assembled into the segmental strips, the strips are secured into the mountin slots 7 by means of cooperating wedges driven home, one beside the other, between the segmental strips and one wall of the mounting slot. The slots 7 are preferably which are 20 effectively secures the undercut and onev lateral face of each spacing piece 9 is inclined to correspond to the inclination of the adjacent undercut wall of the slot. The other lateral face of each spacing piece is formed at right angles to the top and bottom faces of the piece.

A segmental strip is introduced into each slot and is so located within the slot that the inclined faces of the assembled spacin 10 pieces 9 fit snugly against an undercut wal of the slot. The strip is then secured in place by means of compound tapered wedges 17 which are introduced, into the slot between the vertical face of the spacing piece 9 and the other inclined or undercut wall of. the slot. The wedges are arranged in pairs and areso constructed that when driven home the two Wedges of each pair conjointly form a wed e-shaped key which lade strip in place,

and which is prevented by its shape and the shape of its component wedges from being dislodged from the slot by centrifugal or any 0t er dislodging force.

Several'segmental strips are located in each blade-carrying slot and each strip is secured in place by a number of pairs of v Wedges 17. The wed cs 17 are preferably so spaced within the sTot that the-wedges of one pair contact at each end with wedges of adjacent pairs.

One wed e of each pair is provided, across itstop wit a projecting flange 18 which, throughout its length, is of. the same thickness, the taper of the wedge having been 7 cut away. The flange 18 provided on one of the wedges of each pair projects out of the blade-mounting slot 7 beyond the other wedge of the pair and is adapted by being 49 peened over to secure in place a protective strip for the blade-carrying element.

Protective strips 19 are located between adjacent blade-mounting slots 7 andare secured in place at one edge by the flange 18 and at the other edge by an overhanging flange-20, which is formed onthe base portion of each segmental blade strip. The

overhanging flange 20 is composed of over-- hanging or laterally projecting lu'gs which 50 are formed on each spacing piece 9. The

spacing pieces are of such height that they pro ect beyond the'blade-car in'g element an amount which is about equa to the thickness of the protective strip 19.

The individual rotective strips 19 are mounted on the bla e-carrying element after tlie blades .of adjacent rows are secured in aceevel wedge 21 which abuts against and is secured in lace by the overhanging flange 20. The ot er ed e of each piece 19, while 1t may be bevele is preferably provided with a shoulder 22, into which the projectmg flange 18 of the wedge is peen'ed.-- This construction secures .the protective strips Each strip 19 is provided with a.

rigidly in place and prevents them from be ing dislodged by centrifugal or any other dislodging force. It is not always necessary to provide a flange 18 on one 'ofthe wedges of each pair. It is sometimes desirable to provide every second or fifth pair of wedges with the protecting flange, ,which is peened over to secure the protective strip.

A 'modified form of wedge is shown in Figs. 6, 7 and 8, and is adapted to replace the wedge shown in Fig. 5. I The wedge 23 referred to is a compound tapered wedge and is provided with an inclined upper edge 24 which projects beyond the blade-mounting slot when the wedge is located in place 0 within the slot. The edge 24-is so inclined that the thickest end of the wedge is of the least width and the thinnest end of greatest width, and the inclination is so proportioned to the taper of the wedge that an equal 5 amount of metal perlineal unit longitudinally of the wedge projects from the blademounting slot. This projecting edge is peened or calked over to engage the shoulder 22 formed on the protective strip 19 and thereby secures the strip in place.

The segmental blade strips are of such length that a predetermined number of them completely fill one of the blade-mounting slots. The protective strips 19 may also, if 5 desired, be cut in sect-ions and secured in place section by section. The component wedges utilized to secure the blade-mounting strips in place are preferably so spaced within the slots that the ends of the wedges of one pair abut against the wedges of the next adjacent pair. 1

Since it is necessary to leave considerable space between the first and" last pairs of wedges introduced into a blade-mounting slot, .I have provided special means for se= 'curing'the component wedges of these pairs in place-and I have illustrated the same in Fig. 9. A simple wedge 25 and a rectangular key 26 are cut to such lengths as to fit into the blade-mounting slot between the wedges of the first and last pairs. The wedge 25 is introduced into the blademounting slot and is so located within the slot that its inclined 'face contacts with an undercut wall of the slot. The wedge is also of such width that it projects beyond the slot a predetermined amount. The key 26 is introduced into the slot between the wedges 25 and the segmental blade strip. The key and the wedge are then secured in place by peening or calking over ,.the projecting edge of the wedge, so that the key 26 is locked inplace by being enveloped by the wedge 25 and the segmental blade strip.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with'the apparatus which I now consider to represent the best embodiment thereof, but 130 I desire to have .it understood that the apparatus shown is only illustrative and that the invention means. v

What I claim is: 1. In a turbine, an element provided with i a slot, blades, blade-holdin .means in said slot, means for securing sa1d blade-holding means in place. within said slot, protector tector means in place.

means for said element andcmea ns provided 7 on the securlng means for securlng the proslot beside thesblade holder for securing the blade'holder in the slot and for, engagement with the protector.

' 4. In a turbine, an element provided with a slot, a bladeholder in said slot, wedges for securing the blade holder in the slot, an element protector and means on the wedges for engagement with the element protector.

5. In a turbine, an element provided with a slot, a blade holder insa id slot, .a lining strip adjacent to the slot and wedges in the slot having lining strip.

peening edges t9 engage the 6. In a turbine, an element provided with a slot, a blade holder in said slot including spacers having portions entering a recess in the wall of the slot, 'alining strip for the clei'nent and means for holdingthe spacers in engagement wlth the recess in the wall of the slot, saidlast named means having a portion projecting above theslot adapted to be peened over into engagement with the lining strip.

v l i a-slot, a blade-holder in said slot, means for 7. In a turbine, an element provided with Securing theblade' holder in the. slot conil g l ki g Wedges having oppositely p can be carried out by other inclined faces, and'means on one-of the loclring wedges adapted to be bent over the ed e of the s 0t and a lining strip adapted to engaged by the bent-over, portion.

' 8. In a turbine, an element provided with a slot, a blade holder in said slot and having an edge overlying the edge of the slot and locking means for holding said two edges in interlocking engagement, a lining strip and means on the last named means for engaging the lining strip.

9. In a turbine, an element rovided with a plurality of slots, blade-hol ing strips located in said slots, wedges for securing'sald strips in said slots, lining strips for said element and means provided on' one or more of said wedges for securing said lining strips in place.

10. In a'turbine, a blade-carrying element, a plurality of slots in said element, bladesupporting strips in said slots, wedges n pairs within said slots for securing said strips in place, a lining strip between adjacent slots and wedge-supported means for securing said strip in place.

11'. In a. turbine, a blade-barrying element,-

blade-supportin strips for securing blades in a plurality ol rows, a-linin strip'located between adjacent rows of bio. es and means provided on'thev blade strip on one row and row for securing said lining strip in place 12. In a turbine, an element provided with a plurality of slots, bladesupporting-strips in said slots, locking elements for securing said strips within said slots, a lining strip for-said blade carrying element located between adjacent slots and means provided on .on the mounting means of the next adjacent the blade-supporting strip of one row and on 'a locking element of the next row for securing sa1d-l1n1ng stri n place.

' In testimony whereo I have hereunto subscribed my name this 16th day of May, I

FRANCIS HODGKINSON;

Witnesses:

CHARLES W. MoGnEn, E. W. MCOALLIs'rER 'Q